Advice for first-time buyers on selecting a scooter

This started out as a response to a post on a message board; some people have suggested that I preserve it as good advice, so here it is. There’s some US-market specific stuff here, so if you’re outside the US some of this will not apply.

So, you want to get your first scooter. And you see one on Craigslist. How do you know if it is worth considering? Especially if it is your first scooter, and all you know about scooters is that there was one in the movie ‘Roman Holiday’ ?

Here’s some advice regarding buying a first scooter in the US for someone who knows nothing about them. It is slanted more towards ‘what to avoid’ rather than ‘what to look for’, with the aim of helping you avoid some of the worst that is out there.

1. Avoid any scooter before 1960

Pre-1960 parts get difficult, bikes get slower and less reliable, and there are a lot of one-off things that were only done for a single year. Doubly so for models before 1958. Triply so for models before 1955.

2. Avoid any scooter from 1966-1970, (especially ‘150 supers’, and ‘Vespa 150’ or ‘VBB’ models)

This span is a period of very few scooters being imported to the United States, yet are high years for Bajaj production and vietnamese importation (due to the turn the Vietnam war took in 1969-1970). There are exceptions, but I’d venture that 90% of the bikes in this date range that come up for sale are poor quality asian restorations.

Italian production of the round-cowled VBA/VBB/VNB/ ‘Vespa 150’ style scotoer ended in 1965, and continued until 2006 in India. These Indian Bajaj Priyas were never imported to the US new, however many, many of these have been imported since, and they usually have been cheaply refurbished and resold as ‘Vespa 150’ (VBB’s), the Italian model they closest resemble.

The 150 super was exported to the far east in disproportionately high numbers in these years, and many of the worst scooters i’ve worked on are 150 supers with extensive modifications and ‘customizations’ done in the far east.

There is a solid exception to this rule; I wouldn’t shy away from a 1966 Vespa Sprint or 125 Smallframe badged as a Sears; there are a good number of these stateside in good to excellent condition.

3. P series and Stella are usually pretty solid.

Partly due to the fact that they are some of the newer bikes available, partly because they are not as desirable and therefore fewer of them have been thru ‘restoration mills’. Bone stock they are some of the more reliable and higher performing models produced. You also see few grey market or ‘restoration mill’ imports due to the fact that untill recently they were more difficult to import due to not meeting the criteria of over 25 years old.

4. Low miles is a bad thing.

Low mileage bikes invariably have the seals fail within a few months to a year of being pressed into daily rider service. the seals take a set and harden over time. You will need an engine rebuild if you start riding a low mile bike regularly. They do not like to sit unused.

Not that you should avoid these outright; a cosmetically perfect bike with even a seized engine can be ideal if you plan to have a shop go thru the engine and rebuild it and plan accordingly.

5. Avoid any bike that has been ‘upgraded’ to 10″ from 8″.

There are many, many ways to do this conversion, and most have problems, some of them of the severe safety issue type. Very few, if any reputable shops do this, and it’s usually the sign of a bike either done by a restoration mill or extensively reworked by an amateur.

The main differences affecting handling between most 8″ scooters and most 10″ scooters are the results of differences between models that have little to do with the wheel size, and more to do with the differences between models, and even those differences are not as pronounced as some make them out to be.

6. Avoid high performance upgrades.

You are at the mercy of the last person to work on it, and if someone hasn’t done it right it can cost you, or strand you, or leave you with expensive repairs. A mild pipe is ok, but if it’s got a kit I’d say shy away from it as a first bike.

I’d even hesitate to put an exception for work done at established shops; there are a number of individuals who are well regarded by a fair number in the scooter community that I wouldn’t trust to spec and build an engine, for various reasons.

7. Avoid ’12v conversions’,  ‘no battery’, and other wiring conversions.

There are many ways to do this, and some are better than others. Any issues you have will involve trying to figgure out how it was originally wired, what was changed, and if the person doing it knew what they were doing.

8. Stock, unmolsted bikes have less ‘surprises’

This goes hand in hand with the last 3, but a bike that is factory original but neglected is usually a better buy than a shiny repainted one, in the mid to low price range. The more a bike deviates from bone standard, the more likely it will give first time buyer problems.

9. Avoid restored bikes under $5k

It costs alot of money to do a restoration properly. It costs much less to cut alot of corners like the ‘restoration mills’ do. Granted, there are sob stories (got it restored, lost my job, must sell) but if someone has restored a bike properly, they have serious money into it, and even selling it at $5k is usually selling at a loss. Just to give some context, to have a bike restored by a shop such as Scooters Originali, the price STARTS at $8,000. not including the cost of the bike. I don’t even know what I’d charge at my shop because with the few requests I get, once I go over a rough ballpark of what paint and the motor work would cost they usually lose interest. To be honest few customers have the stomach or the pocketbook for it.

10. If the scooter is over 25 years old and the engine has never been apart, budget for an engine rebuild.

While you might get lucky, from my experience, any scooter over 25 years old that has never had the engine open has seals living on borrowed time. Plan to pay to have the engine rebuilt within a year or two.

Yes, there are exceptions to these rules, but follow them and you’ll weed out alot of the bikes more likely to give you problems. If you need advice on a specific bike, i am willing to weigh in on scooters for people. Just contact me.

Advanced stator surgery: Building a 6V VBB compatible P stator

So, I’ve run into a problem I’ve had to solve before. Figured I’d write it up.

Most non-battery 60’s and 70’s Vespa scooters use a system first used on the VBB2; it’s a quirky system where the load functions to limit the voltage. The whole system balances without a voltage regulator. Problem is, because of the way this system works, it’s completely baffling to most people, and you can’t just hook up a later engine from a P (or PK , for small frames)  easily. And a lot of people want to do that. You can hack into it and fiddle with the wires, add a few, change the brake switch, and you can come up with a system that sort of works, but really the best way is to rewire it from the ground up.

But, there’s an easier way. Piaggio did carry this style of 6V non battery electrical system forward into the P Stator designs. In fact, they even manufactured a few non battery, non turn signal, 6v P200’s in the late 70’s. But alas, that stator isn’t available any more. However, there is a stator much more plentiful and still available new that had this lighting system, in this stator design.

The ET3.

These use the same core setup as a P, but on a smaller diameter backplate. And the ET3’s were pretty much all non battery 6v. We can use the ET3 stator and transfer the coils over to a P stator to end up with a stator that is compatible with that old 6V bike we want to drop our P engine into.

So first: The stators.


Late US P on the left, ET3 on the right.

As you can see, they are very similar in design. What we will do is remove the coils from the ET3 backplate, and transfer some, or all to the P backplate.

There are wires tying the coils to each other and the odd ground wire in the center. These connections need to be de-soldered. There are also the wires that go out to the junction box. These need to be either cut or run in such a way as to allow the coils to be removed. When doing surgery on stators this old or where they are going in a vastly different setup, I usually cut them and rewire the stator when I am done, making sure to leave enough length so I can identify the color of the wire that went there originally.

These coils slide onto the center core, and then have one of the laminations folded down to lock the coils in place. Like this:


So, that in mind, let’s begin. We un-bend the laminations like so:



It is also important to note that two of the coils overlap the other two, so it matters which ones you remove first.

These are the ones that need to be removed first:


Now, to make this work, you are really only after the yellow/blue coils. These two power the tail, brake, and pilot lights. For the headlight, one can choose to use the P’s headlight coils, if the donor stator is an American market bike, or any two of the lighting coils if it is the European market style stator. If this is done, you end up with a hybrid; a 12V headlight yet a 6v brake/tail/pilot circuit. However, I didn’t trust the headlight coil on this P stator so this one is being built as a full 6v system, using all of the coils from the ET3.


And here we have the core from our donor P stator. Then, we remove the coils from the ET3 stator. As I remove them, I like to place them on the table in such a manner that I do not get them installed incorrectly.


And there is a problem.

See, there are actually two different types of P stators. This is the later one that has extra laminations so the lighting coils can be a larger diameter. You can see them on the picture above. The ET3 stator we have, being an original early one has the thinner coils. So these extra laminations need to be removed.


On this one, I cut them in two places. The first shown here; then I cut on the other side of the next one, then ground down the rivet. After that, it was a matter of spinning them on the rivet and gently prying to get them loose.

Granted, not all P stator kitbashes will end up running into this early/late difference but if you run into that, you’ll know what you are looking at.


And here is the stator with the extra laminations removed so the earlier coils will fit on it.

Incidentally, visually it is very apparent that these coils have very different characteristics, owing to the vastly different gauge and number of turns of wire on them.


Here are the ET3 coils on the P backplate, before being re-wired.


Here they are with new wires installed.


I did have to get a little creative with the grounds, as i had to cut the original ground tabs off to get the extra laminations off.  I ended up grounding to the pickup mounting screw instead.

I just have to put the outer housing on them and cut to length and install connectors, and this stator can be installed onto any P engine and make it connect directly without adaptation to the vast majority of older non battery bikes. If done right, it should power a 12v 35w headlight and 6v pilot, brake and tail without any modifications to the harness, or adding any voltage regulator.

A little different than most people would do in this situation, but easier in some regards.

If one wants to undertake this modification, ET3 stators are available new in two types:

RMS brand and OEM Piaggio

Either will work, and as usual the Piaggio is more expensive.

Visiting our old Ape P501

I’ve taken a trip back to my parent’s house for Thanksgiving and had the opportunity to visit my old P501.


My old 1980’s Italian market P501 ape.

See, when i relocated from Chicago to Seattle, There was not enough space in the truck to bring this along  so i traded it to my Father for a Riva 180 and a Puch Magnum, which i sold once I got out to seattle.

How i came to own this is that while i was working at Scooterworks in Chicago, we imported container loads of used Italian scooters and restored Fiat 500’s. However, as the supply started to dry up and the US economy stumbled, we were importing fewer and fewer scooters until word came down that we were only getting a 20 foot container instead of the regular 40 foot container we’d normally get. So, I asked if I could get an Ape if I paid the difference in shipping costs between a 20 and 40 footer. To make a long story short, i ended up paying something like $500-600 delivered to Chicago.

From what i can tell, this ape was used somewhere around Genova.


The ape has about three or four of these bumper stickers on it.

The ape has three or four bumper stickers for this Italian radio station on it; apparently this radio station existed from 1977 till 2001.  ironic; as this vehicle has no radio…..


This is probably the coolest thing on the ape; the original dealer decal from where it was sold in Italy. L’Alveare means ‘the beehive’ in Italian. A cool choice for a place that sells Apes (bees) and Vespas (wasps).


Here you see the controls on the column; the orange painted lever on the right is the parking brake.  the lever on the far left is the reverse lever. Engage this and the four gears on the handlebars become four reverse gears.  The red lever and the one opposite it are the choke and heater controls.

The heater lever controls a flap in the rear of the Ape; In the off position it dumps the air that has cooled the engine out onto the pavement. Pull the lever and this flap closes and the air gets ducted into the right hand frame box beam and comes out under the seat to heat the cab. it actually works really well. the original system has what looks like an o-ring groove cut into the exhaust flange and the cylinder head. These are connected with passages and the head has a hollow tube that sticks out beyond the cooling shroud. Because of these design features if there is an exhaust leak it doesn’t make it’s way into the heated air and into the cab.

20141123_141122Here’s a shot of the engine; that dot to the left of the bolt in the cooling shroud is the aluminum tube I’m talking about. you can also see the Mikuni 28 conversion i put on it.  This Ape also has a  230cc Polini cylinder on it.

It’s a fun ride, and much larger than my Ape 50; I once had three people in this and rode it thru a few Chicago winters. It honestly sounds just like a big, rumbly P200 when it is running.

Re-snaking an expansion chamber

Unfortunately, the images to this post were lost in a server crash.  i’m preserving the text in case it is of any help to anyone.

Here is the Ape 50.

There aren’t any really high-end exausts available to fit this, so we are going to modify and re-snake a Hammerzombie pipe to fit it.

First thing i did was get access to snake the exhaust.

As i currently do not have the fuel tank installed or any fluids in the engine, it was a simple matter of removing the battery and tipping it on it’s side.

This is the Hammerzombie, in it’s unaltered state. A great smallframe pipe.But, when put on an Ape,  the truck bed got in the way of the header, and the differential got in the way of the main body of the pipe and the axle got in the way of the muffler.

so, we’re going to fix that.

First, we had to cut the header along the seam in it and rotate it to get it away from the truck bed.  we used this cut off saw, but found out later the band saw would have gotten us a better cut.

Here we are, cutting the second cut.

It looked good, so we tacked the header together at the first pipe with a TIG setup.

And then did a test fit.

This went well. So we did the next cut.

We tried the band saw, but on this large section of the pipe it was deflecting to much, giving us not a straight cut.

So we got it most of the way with the thinwheel, then switched back to the bandsaw to finish off the cut.

And then a test-fit. and then tacked together.

we were worried a little about the pipe coming too low, and killing the ground clearance.

We tried another test fit. We ended up going with a slightly different routing on the final weld, though.

And here is the pipe fully welded and good to go, except for the bracket modifications.

And here we go. the final picture. looks a bit different than the standard Hammerzombie.

All in all, i’m happy with it. we just need a piece of  1″ angle stock and an exhaust clamp to make the bracket and it’s good to go.

Reinstalling the Ape 50 engine

Unfortunately, the images to this post were lost in a server crash.  i’m preserving the text in case it is of any help to anyone.

Here’s a write up on reinstalling the Ape 50 engine.

it’s going to be more write up than photodocumentation, as i didn’t take too many good pictures of this step.

So, in this picture I have the front engine mount bolt in place, and both axle shafts removed. i’ve also removed both the rear shocks as I planned to replace them anyway and this seemed like a good time to do it.

Of note, you’d typically want to have the cooling shroud on the cylinder, but I left it off since I have to modify an exhaust and figured that would make it easier.

Next, swing the engine up into place and bolt up the engine cradle.

Then, I replaced the rear shocks.

Here’s a shot of the old shock and spring next to the new shock. These shocks were pretty reasonable. I’d recommend replacing them if you have an ape 50.

To get the shocks out, there’s two covers held in place by two screws each in the truck bed. remove these  to get access the top shock mount. remove these nuts top and bottom to get the shocks out.

Then you install the half shafts. These slide in, and then there is a thrust washer that goes against them. Of note is that this washer has a tab on it. This tab has to line up with a corresponding notch in the differential.

Then you install the circlip.

At this point, you’d probably hook up all the electrical and the control cables. I have other things to do first so i didn’t.

Assembling the ape 50 engine and differential

Unfortunately, the images to this post were lost in a server crash.  i’m preserving the text in case it is of any help to anyone.

Alright. sorry this has been a few weeks late but here it is; assembling the differential and engine on an Ape 50. It’s been a busy spring here at Hodgespeed.

So, here you have the four engine case bits for an Ape 50 and the differential. First you’ll have to swap the cylinder studs for the longer 125 studs if you’re upgrading displacement as we are.  you’l also need to install the Christmas tree in the flywheel side case and the clutch basket in the other main engine case along with all bearings and seals.

Now, attach the inner differential case to the clutch side case.

Here you’ll see the first mistake i made. You need to insert the three differential cover bolts on the left hand side in this picture into the case, before bolting the two pieces together. otherwise, there’s no way to get them in the holes, similar to those two annoying case bolts on a handlebar bike engine. save yourself the do-over and put them in before you bolt these case bits together. you need to use gasket goo (witch i personally dislike) on this joint. there is no paper gasket.

Now, insert what is the rear axle on the scooter, but is the output shaft to the transmission on the Ape. make sure to line up the shifter with the shifting fork, and get the gears lined up with the christmas tree. some people like to install this shaft and then put the gears on, as it is slightly easier that way.

Next, we’ve got to put the differential together.

Here you see how all the internal bits go together. it’s pretty straightforward. three gears and a shifting fork for the reversing gear. gasket goo again here, no paper gasket.

Now, back to the other side. from here it’s like a regular smallframe except way simpler because there is no kickstart mechanism. i never realized just how much work that added getting that lined up, but this thing just flew together in no time compared to a scooter smallframe case because of this omission. no runner biffers to install, not spring to fiddle with, no quadrant to line up. just set the parts in the engine and bolt together.

First you install the crankshaft, then grease the gasket surface.

Then you put the gasket on.

Then you grease the gasket

Then you install the flyside case.

If you’re using 50cc-style ball bearings, you’ll have to tap into place. if using the needle style bearings used in all other displacements, it’ll just slide right on.

Notice these two case bolts:

Leave those out for now, because you need to use them to install the engine mount.


Now, install the crank gear. to get good speed you need to go way higher than you’d think, as there is a 1.68:1 reduction in the differential. as a result, the gearing i went with was so tall i needed to clearance the case a little to fit it.

now install the clutch.

Then install the clutch push plate and cover, repeating the grease-gasket-grease from earlier.

Install the top end.

And here’s the issue i found. Most scooter carb setups do not work with the Ape because of the T-shaped engine mount. The reed block will not go together here. the solution? Polini makes a reinforced performance engine mount. here they are side-by side.

the mounting points are the same, but it is Y-shaped to clear whatever carb you want to run.

See? the carb manifold now fits. Here’s another shot of it.

And now to resolve one of those weird little things. there’s a hose that goes from the stock carb to the intake tract, and i didn’t bother to look too hard at it to figure out what it did. needless to say, the 25mm carb doesn’t have this bit, and I’m just going to close it off for my build.

I used a bit of stainless rod in some vynil tubing, and then put that over the nipple on the case.

now, install the stator and flywheel. And here we have another issue. the electric start gear interferes with the malossi 136. score the cylinder fin with a cutoff wheel and then grab it with pliers and break it off. use a grinder to clean it up and to clearance it so it doesn’t rub.

install the flywheel cover and cooling shroud and it’s pretty much ready to go in the bike.

next installment we put it in place and possibly wrestle an exaust snaking.

Ape 50 top end and gearing comparison

Unfortunately, the images to this post were lost in a server crash.  i’m preserving the text in case it is of any help to anyone.

Most of the parts for our shop truck have arrived; I wanted to take this chance to illistrate the difference between the stock parts and what i’m going to.

First up: the cylinder and piston

As you can see, it’s bigger. much bigger. It’s also going to have a longer stroke. this takes displacement from 50cc to 136cc. In addition, it has a much improved set of transfer ports inside the barrel walls, improving the changeover from burnt gasses to fresh fuel and air. It is also set up for a cylinder inducted reed valve and larger carb, giving it much more power overall and a much wider spread of power.

Next, to take advantage of the power-

This is the old primary gear next to the new one. the old one is the one with the wee tiny separate gear and is a 14/69 tooth count, ratio 4.93.  the new set is a 29/68 tooth count, so 2.34 is the ratio.  If you’re coming from the Vespa smallframe world and are familiar with their gearboxes, you might think i’d lost my mind. when put in a smallframe scooter, this ratio gives you about 85mph @ just over 8,000 rpm. Fear not; there are other factors at play.  first off, the gearbox on this ape is different from the typical 4-speed scooter gearbox.  Actually, it’s more of a scooter 3-speed with a higher fourth gear added. (Remember the zirri short 4th gear kits? they use a modified ape 50 3rd gear as a 4th gear). it’s a 26/42 1.62 ratio 4th gear instead of a 22/46 2.09 like the scooter uses. But wait- that means if this combination was in the scooter, it’d get 105mph @ 8000 rpm. How does this work with the Ape 50? It’s the differential. there is a 34/52 1.53 ratio reduction in the differential. This drops the gearing considerably, to get us a ratio that gives 68mph @ 8000 rpm. in addition, this specific kit gives us some leeway to adjust the gearing easily later. there are 26,27,28, and 30 gears available separately that can be swapped without removing the engine from the frame. This gives us a range of steps from 62mph @ 8000 rpm to 71mph @ 8000 rpm. This should work well if we need to later fine tune the gearing once this is in service.

Stay tuned; i’ve already modified the cases for the new top end and expect to post that article next week. Feel free to ask any questions you might have in the comments; i’ve enabled using facebook to authenticate users so you shouldn’t even need to sign up for an account or anything,

UPDATE: This kit turned out to be a hair too high, even with the 26/42 combo. it might be right if used with the DRT short 3rd/4th christmass tree.

Rebuilding the rear brakes on the Ape 50 – Part 2

Unfortunately, the images to this post were lost in a server crash.  i’m preserving the text in case it is of any help to anyone.

So, when we last left off we had removed the half-shafts from the Ape, and had removed the brake backplate and drum on one side.

Yesterday the parts arrived, so last night I finished this up. so. here’s how you take apart and rebuild the backplate and brakes. First, remove the brake slave cylinder.

This removes via two screws that hold it to the backplate.

For comparison, here’s my old cylinder and the new one next to it. for some reason the bleeders were pretty much completely corroded away and would have been completely unserviceable. the other wheel’s cylinder  was actually WORSE than this side.

The next item you have to address is these little springs that pull the brake shoes towards the backplate.

Just grab them with a pair of needlenose pliers and unhook them. Next, push the brake shoes off the pivot rest. they should slide right off. Like this-

One important note – notice how the spring’s hooks are offset to one side on that bottom spring? remember that. you need to have that orientation correct when you re-assemble them or the spring will want to pull the shoes off their rests and out of the alignment they need to have.

Once the shoes are off the backplate, unhook the bottom spring. you can push the shoes together to take the tension off of the spring.

Then pull the shoes apart at the bottom to remove the bar the cable brake uses. remember which side goes towards the backplate, as it is different.

Reassembly is pretty much the reverse of these steps, with a few exceptions. of note is the replacement RMS brake shoes. in stock form, the hole for the smaller spring was not big enough for the spring to fit in so I had to enlarge it with a drill. I recommend making sure all the springs fit in all the holes before attempting reasembly.

For reassembly, install the bigger spring and the e-brake bar. make sure you get the bar in properly as it is different front to back and left to right.

once that is on, it should look like this:

next, i installed the master cylinder into the space in between the shoes. Then i installed the smaller spring opposite the brake sure you have it on right. Here’s the correct and incorrect way, shown against the backplate for reference.

Before putting the shoes onto the backplate, put the brake cylinder in place on between the shoes. then put the shoes into place.

One huge thing to point out- see those two bolts to hold the backplate to the bearing holder? put those in now, because these two ones can’t be installed into their holes if the brake shoes are on the backplate.

You’ll need to get the brake shoes onto the piece opposite the brake cylinder. it’s not easy, but with a little careful levering they pop into place.

Once you get the shoes seated in place, bolt in the brake cylinder.

Re-install these two springs:

And the brakes are back together.

Rebuilding the rear brakes on the Ape 50 – Part 1

Unfortunately, the images to this post were lost in a server crash.  i’m preserving the text in case it is of any help to anyone.

Last week, we started rebuilding our Ape 50’s engine. While we wait for parts to arrive, we’re going to rebuild the rear brakes.

So, when we got this thing it wouldn’t roll. after we removed the engine it became clear this wasn’t in the differential, it was in the rear hub/brake drums.

And there’s the rub; the brake shoes were stuck to the drum. a pain-in-the-ass situation to say the least, not even taking into account the fact that i hadn’t ever had one of these apart.

In the spirit of  “in for a penny, in for a pound”, I decided that as long as i had to take the rear wheels apart, i’d get new brake shoes, cables, and hydraulic slave cylinders.  The slave cylinders ended up costing $15 a piece, so it really was a n0-brainer.

But how to get it apart?

I ended up removing the wheel bearing housing from the A-arm.

 The brake line, two bolts, and the nut that holds the shock on the bottom is all that held it on.

I managed to get the four bolts out of the bearing holder that held it to the brake backplate; once I removed these and the nut on the shaft, the half-shaft and wheel bearing housing  just lifted off the assembly.

This is definitely not the preferred disassembly order; but, it did make the shoes and the hub easier to separate by making the assembly less cumbersome.

From here, I had to tap, beat, and pry ever so carefully. If one is VERY careful not to overtighten them by mistake, the rest stops for the brake shoes can be adjusted to their relaxed position. these are the two hex head bolts at approximately 12:00 and 6:00 on the picture above.  I managed to walk it free and get them separated.

I’ve also decided the wheel bearing holders will get all new seals since i have them apart.

Watch the website for part two, witch will detail the re-assembly of the rear hubs and bearing holders, to be written when the parts arrive.

Inside the Ape 50 engine.

Unfortunately, the images to this post were lost in a server crash.  i’m preserving the text in case it is of any help to anyone.

Hello World!

Just last week Hodgespeed acquired something not often seen in the United States. a 1998 Piaggio Ape 50.

This is the ‘smallframe’ Ape, and is even smaller than the main line of full size Apes. In some european countries, these qualify as a moped, and get much more lenient registration and driver licensing requirements.

It’s powered by a variation of the Vespa smallframe 50 engine.

See it back in there?

Because it is fundamentally a Vespa smallframe scooter engine, there’s tons of tuning parts available to fix the 23mph stock top speed. Yep. 23 mph top speed. takes four gears to get there, too. Piaggio did make a 125cc version of this vehicle starting in 1969, but stopped production in 1974 after only 1700 or so were made. The lenient laws regarding 50’s made the 50 the king in sales, but not in performance. The ape 50 has been in continuous production since 1969, till the current day.

When this project is done, this will become our shop truck; we hope to have it be the chase vehicle on rides and rallies in the Seattle area before Seattle Scooter Insanity this July. It should be able to haul a single scooter when we’re done with it.

Because this engine is not too common, yet familiar, I think there might be some interest in seeing what it’s like on the inside of these. So, I’ve documented the tear down for the rebuild on it.

Unfortunately, i didn’t document actually removing the engine from the frame. That was a real bear.  Suffice to say, if you have to remove an engine from an Ape 50, the thing is light enough to use milk crates as jack stands. You have to unbolt one of the A-arms from the frame and the shock and remove a circlip from underneath the boots on the differential to remove the half shafts.

Anyway, here it is, in all it’s glory. the Ape 50 engine.

This is the engine, propped up by a brass hammer on my work bench. if you’ve ever had or worked on a smallframe i’d imagine these angles look a bit familiar to you.

Here’s a shot looking from the side of the engine the rear wheel and rear shock would mount if it were a scooter. because this is an ape engine, this is actually the front; the cylinder faces to the rear on the Ape 50. On the Ape 50, the differential bolts to the engine case where the brake backplate bolts to the scooter version of the engine. that’s what that lump hanging off the back of the engine is. you can also see where the gear cables attach to the top of the engine, and where the reverse-selecting cable attaches to the differential.

Opposite the flywheel. for context, you can just see the starter poking out from behind the exhaust. just to the right of the exhaust is the differential.

Here’s the bottom.Note the stamped steel bolt-on cradle where you’d expect the swingarm to be. Also, the clutch cable on these is routed a bit differently than on the scooter. The cable stop is cast into the differential case just out of frame at 12:00 in this picture. Notice also- if this were a scooter engine this would be the bottom of the engine where the cables attached. However, on the Ape the offset linkage inside the case is omitted and the cables are attached to the top of the engine.

And here you can really see that stamped steel ‘swingarm’. Polini actually makes an aftermarket version of that  piece. I’m tempted to order one. You can also see the exaust. Becasue the engine faces the opposite direction in the ape as in the scooter, mounting a scooter pipe wold result in a forward facing tailpipe. In addition, one would need to come up with a bracket to mount the pipe to since there is no swingarn. neither is insurmountable; i expect to mount a hammerzombie pipe on this before i’m done.

And here you can see the differential with it’s cover removed. The big bit on the right hand side sticking up is the Planetary Gear System there are two freewheling planet gears inside there, and the sun gears are on the end of the axle half shafts.

The other two gears are doing something clever- first, the lower left hand gear. this is a single piece with thre gears on it. the lowest you cannot see in this picture, but it is always engaged with the ring gear on the planetary set. Above that, is a larger gear. and on the end, A helical Gear to drive the speedometer cable.

the upper left gear is freesliding on the splined shaft normally, as in this picture, it drives the ring gear from the shaft, propelling the Ape forward. now look at this picture-

In this shot, my grubby fingers are simulating what happens when you pul lthe lever in the cab to shift into reverse; the gear is lifted away from the ring gear, and drives that gear with the speedometer drive on the end. thus adding a reduction and driving the vehicle in reverse.

This shot shows that gear inside it’s shifting fork in the other side of the differential case. This gear is dormally held in the forward position by a spring outside the case.

And here we find what i find the cleverest bit in the engine. there is a sleeve cast into the differential case that holds a needle bearing and seal that is exactly the same outside diameter as the normal smallframe rear hub bearing. this keeps the differential oil and gearbox oil separate.

And here’s what that mates up to on the other side. the end of the axle is this club-like splined shaft that that sliding gear in the differential slides on. notice the five large studs here instead of the two the smallframe scotoer engine normally has.

And surprise- a P-style stator. even more interesting, it is actually wired and color coded the same as an american market 70’s P200 stator. the crankshaft is one of those 20/20 mm types. not the ETS / P-style 24mm i had been expecting. This is one of a few things where developments on the scooter side of things did not make it back over to the Ape side of the family.

And here we get into the clutch cover area. notice that this clutch has six springs in it, not one large one. this late PK style clutch is kind of like the ‘cosa’ clutch of the smallframe.

Here you can see how low this thing is geared. look how tiny that crank gear is! More on gearing later, however.

and the clutch cover. it’s gear driven, not lever driven. and the button isn’t brass, either. on this engine, believe it or not the pressure plate has a ball bearing in it.  Curriously, the oil passages that feed oil into the center of the clutch and the backplate do not exist in this case or the clutch cover. perhaps Piaggio thought the ball berating didn’t need as much lubrication as the brass bit they used on earlier engines did.

Here’s a side by side of a early 2000’s LML smallframe case for comparison. notice how much rounder the Ape case on the left is at the bottom. since the shifter cables attach to the top of the engine rahter than the bottom like on a smallframe. also notice that the holes the stamped steel swingarm thingamajig are in exactly the same place as the cast swingarm is attached to.

look at all the meat on that 50 jug! anyone got a 75th oversize piston? In all seriousness, you can see from this the potential to increase the displacement. in addition, the 50 has a shorter stroke than the 90/100/125 small frames. so longer stroke plus cylinder kit would give a massive improvement on this engine.

Wee tiny piston!

Here is another interesting thing; when i saw the manifold had three studs, I immediately thought it was like a 3-stud PK manifold  (on the left) . Not so! the spacing is different. upon closer inspection i realized Piaggio had just added a third stud to the earlier 2-stud smallframe pattern. look at this picture:

See? a stock 90 manifold fits, leaving one stud out in the cold, unused.

and here’s the christmas tree. notice, there are no notches for a kickstart ratchet. early ape’s had a hand-start that used the scooter kickstart mechanism. Sadly, that feature has been dropped from this model.

And here you can see the strange axle that also serves as the input shaft for the differential. And while we’re on the gears; looking at this gearbox, something didn’t look normal to me so i started counting ratios. this has a very wide ratio gearbox, with very high 4th gear and very low 1st gear. at first, this confused the heck out of me, until i realized what they had done. On smallframe scooters, the three speed top and bottom gears are roughly equivalent to the top and bottom gears of the 4- speed with 2nd  on the 3-speed splitting the 2-3 gap on the 4. However, on this gearbox, 1-3 are roughly equivalent to 1-3 on the 3-speed scooter gearbox, but with one higher gear added.

Here you get a shot of the inside of the case. Very small frame-like.


And here’s a side-by side of the clutch side case. there are definitely differences; the Ape lacks the reinforcing webs the scooter motor has  the swing arm, as the Ape engine is not loadbearing.  The ape also has a few reinforcing ribs added, most notably on the edge next to the bearing the clutch basket primary rides on.

Well, that’s it. my tour of the inside of an Ape 50 engine. Keep watching here, as once business picks up enough for us to spend the money we’ll be building a real screamer of an engine out of this.