78 hobbit restrictions

i recently bought a beautiful garage kept 78 hobbit and started working on it and i was wondering if any one knows about its governor at all or how to tweak it??

Re: 78 hobbit restrictions

It's fairly simple. If you have a PA50, then it's restricted by the variator plate whic is part of the complicated clutch/flywheel system.

If you have a PA50II, then you are basically unrestricted, and will go 30mph pretty easily (had one this summer....ran great).

If you are stuck with a PA50I, then there's not a whole lot you can do asside from popping an Airsal kit on there. You could get a PA50II variator plate and cut it to fit. But this isn't recommended. Variating engines are great, but rely on specific balance to run the right way. The Hobbit has the same variator plate system as the Ciao....in fact, they copied the Ciao. Peugeot and Motobecane function similarly, but the whole engine swings.

Here: this guy explains it all for you. Pretty clear.


Re: 78 hobbit restrictions

My friend stuck a performance exhaust on his hobbit, and that thing flies! I don't recall what kind of exhaust it is though.

Re: 78 hobbit restrictions

I've heard the same thing. If you own a PA50II and drop a Proma Circuit on there it'll go about 5-8mph faster no questions asked.

However, Proma is in the process of being bought out and those pipes are no longer manufactured. Your best bet would be to somehow retrofit/make your own from a peugeot pipe since that also comes off the front/bottom of the engine. You'll see....it's not easy to get at...but if you're crafty you can do it.

I did just see a PA50 (20 mph version) with an Airsal on it. I think he said that he did nothing to it other than put the kit on it.....oh...he did have a Proma pipe though. But otherwise it was stock everything - carb, intake (Hobbits have stock reed valves) etc. And it would go almost 50!

Re: 78 hobbit restrictions

Raymond Rexroad /

Be careful, there is some mis-information going on here!

A PA50I (red in color) is different is more ways from a PA50II (yellow in color) than the variator.

The cylinder has different porting;

The carb is a 10mm versus a 12mm (and jets are different sizes); and

The muffler is different (higher flow design).

I put a PA50II variator on my PA50I with no difficulties - to say that it is not recommended is not fully consistent with other sites (including some posts from this site).

In the end, if you want "bolt-on" simple, then I agree that a performance exhaust is your best bet - although it will be difficult to find and expensive ($150 or more). You should still check to see if you will need to up-jet (plug chops - search this forum).

If you don't mind wrenching and modifying, it all depends on how fast you want to go. If you want to go PA50II speeds (about 30 MPH), you can do that for about $100. I ported my cylinder, bought a PA50II carb and reeds/manifold, installed a PA50II variator, added a cheap exhaust, and we go 35 MPH.

I wish I had a better exhaust, but haven't needed it to get to the speeds we wanted.

I just bought a second Hobbit - this one a PA50II. I intend to try to graft on a BiTurbo exhaust (readily available, and less than $100). I'll post the results as the project progresses.

Re: 78 hobbit restrictions

Raymond Rexroad /

I should have mentioned that a Proma Circuit exhaust - and pretty much any other that I am aware of, is made for a PA50II cylinder. The exhaust port opening, including the machined area where the exhaust mates to the cylinder is larger on a PA50II than a PA50I.

The point? An aftermarket exhaust will not "bolt up" to a PA50I. I would expect that some could be modified to fit, but if you expect a "bolt on" experience, you are out of luck!

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