1959 motobecane av88

i’ve finally finished this semester and the weather’s good and i’m able to get to work on my 59 motobecane riverside av88 ( this one )… it seems to mainly need some adjustments/tuning, and not so much part replacing – at least, i hope that’s the case as my first few searches on mopedwarehouse.com and mopedjunkyard.com didn’t seem to come up with anything for models made so early.

a few questions…

1) there’s a fuel leak – from around the fuel valve, the previous owner said he thought it was an o-ring problem. are the fuel line parts on a 59 av88 the same as those on a 70s model?

2) i’m a bit clueless as to some of the main functions of the bike… sort of embarassing, but i need help anyway. i understand these things have clutches… but are you actually changing gears? the manual seems to imply that it does this automatically…

3) from what i understand, when you start to pedal the drums on either side of the engine should start spinning, yes? on mine, the belt catches on the variator but that doesn’t make the drums spin. they only barely start to try to spin, you can hear some scraping when this happens, but they don’t even make one full rotation. what should be happening, and how can i make it happen?

4) anyone have any tips on tuning this thing for a bit more speed? i’m not looking to go crazy on it or anything, but it would be nice to be able to go faster, like 40 or 45, or at least to get to 35 quicker.

geez… sorry for so many questions, i just want to get this thing running and learn as much as i can about it in the process! thanks to anyone who will offer any answers/advice.


Re: 1959 motobecane av88

Jason Luther /

that bike is so cooool. i have a riverside made by benelli, i love these old peds. im not sure on the o-ring, but if you cant find another exact replacement, you should be able to fashion something else. the clutch is a centrifical clutch (automatic) as the motor spins faster the clutch engages by itself and then your off, so no shifting. just make sure you have the proper trans fluid and its fresh and at the proper level. i cant help you with the variator question ive never seen a motobecane. as far as tuning, make sure your timing and point gap is set correctly, and that you check the spark plug (do a plug chop) to see if your mixture is okay. ive always been reluctant to do anything too radical to my riverside since its so old, and expansive to fix should something blow. get everything runnning properly first, than think about performance tuning it. sweet ride -jason

1959 motobecane av88

Nice bike!

Isn't this the same Motobecane that has shown up here a few times in the last month or so?

Re: 1959 motobecane av88

nice freakin bike.. nice condition too. i wouldn't modify it for more speed since it's got that classic look, imho... and it might not take the stress. If it gets you to 35 MPH count your blessings since most bikes only get to near 30 or less.

I am going to guess this bike has a common variator setup. If so, the variator spins when you pedal. This spinning motion (centrifugal force) closes a tiny clutch mounted inside, just behind the variator. That clutch grabs (is supposed to grab) the crankshaft and pedaling makes the turn the engine over. (It sounds like this little clutch is slipping) This little clutch stays engaged whenever the engine is running but doesn't contribute to anything beyond getting the engine started.

After the engine starts to run and spins faster, another clutch, call it the main clutch, acts like a normal centrifugal clutch and is always engaged above some RPM, an RPM just a little faster than your normal idle RPM..

Hopefully someone owns one or knows about your bike and can help you with specifics.. hang in there.

Re: 1959 motobecane av88

Keith Hannah /

Hi jeremy, nice looking bike.

1) The fuel valve/petcock probably interchanges. If nothing else maybe someone around here has a junk one from a later model that they can let you use just to check. I've got one I'd be willing to send you, but if someone is closer, or maybe in the same town, it would make more sense to get it from them.

2) As jason said, the clutch is automatic. It's centrifugal. On a bike like yours the clutch, which is dry, and variator are the components that act as a transmission. So there is no fluid.

3) When starting you need to use the decompression lever to make the engine easier to turn over. If it is the same as later Motobecanes the decompression lever is the one (other than the brake lever) that is on the left side of the handlebar. To be sure, follow the cable coming out of it and see if it goes to a little spring loaded mechanism on the head, right next to the spark plug. The little lever on the other side of the handlebar should be for your choke. Follow it's cable and see that it goes to the carburetor.

4) Have to agree with jason on this one too. First make sure it's running right, then think about performance. If you run into problems while trying to up the performance, you won't know where to start looking if it isn't running right to begin with.

Not many bolt on performance parts available for the MBK either, creativity is required to get speed out of one. Personally I'd try to keep an old one like that as stock as possible.

Re: 1959 motobecane av88

I agree with Keith, keep it original as posible. Yet, I disagree with him. It is your bike, if you want to modify it for performance do it.

That being said I would sugest finding out if a later engine would fit. If so mount the newer engine and modify it and save the original engine in case you want to go back to stock some day.

Re: 1959 motobecane av88

It is the best moped of the world keep it original, it can go up to 60km/h

Re: 1959 motobecane av88

What a beauty!!!

YES! Just keep it original!!! and don't sell it! In years you will be able to get good money for it, I am sure there's not much of them left out there!


Re: 1959 motobecane av88

Wow, another person in this country has one of these. Mine is '60 SP50. Looks very simular except for the headlight and the gas tank. Mine is in horrible shape. I have replaced the fuel line, cables, and grips. I rebuilt the clutch(too much work to talk about now) and had to order a new clutch needle bearing. I still have not been able to find a tailight or a set of whitewall tires. It has been fun trying to get it running and I might try to start it this week when I get a day off. Kenn

Re: 1959 motobecane av88


you should email me. I also have a SP50, and can probably help a little. At the very least, its nice to talk to someone who has one of these things.

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