Souping up a Motobecane

Last year I bought a '78 Motobecane 50V as a basket case. I had two motors in pieces, one an older Dimoby lower end, and the original Variator that came with the moped.

I mixed and matched and built one motor. Not a bad investment for $30.

It runs fine, but I'm wondering if anyone has any tried and true hot rod tips for this moped. I've really enjoyed tinkering with it and thinking about cutting the piston and doing a port job.

Anyone have any do's and dont's on this machine?

Thanks

Re: Souping up a Motobecane

i know simon recently got a polini exhaust for the motobecane and a (i belive) 16mm dellorto carb with a manifold adapter for the motobecane from somewhere in Italy. i think Polini also makes big bore kits (www.polini.com) but i dont know anyone who has actually tried one... good luck.

casey

Re: Souping up a Motobecane

Ron Brown /

I have a couple of 1978 Model 7s. I don't know what your air cleaner looks like, but I removed mine, then jetted the carb for max speed, then modified the air fiter to not be as restrictive. I am not sure how much improvement I got but it was significant.

I think the carb is a smaller diameter than the intake and could probably be enlarged.

Ron

Re: Souping up a Motobecane

It's true. I haven't gotten it running very good yet, due to some throttle problems, but when I do I'll post here to let you know. You can mount a dellorto performance carb on a motobecane, as long as you have the right adapter. You can get adapters from the Moped Warehouse.

Unfortunately, performance parts natively designed for the Motobecane are rare. It's not as easy to mod out as an Italian bike.

simon

Re: Souping up a Motobecane

I'm not sure which equipment was original with my moped. One intake was curved, and another was straight. One air cleaner was a rectangular box, and the other was a small round thick disk. I used the straight intake, and the small round air cleaner. I got the original carb back on since the top was still attached to the throttle cable and I just simply used the carburator that fit.

Thanks for the tips!

Re: Souping up a Motobecane

Ron Brown /

Measure the carbs and intakes so you can use the largest. The curved vs straight is most likely due to bodywork fitting so you may be limited.

As before, jet without an air filter, then using what you have or can make, set up an air box/cleaner which flows well enough not to screw it up.

Ron

Re: Souping up a Motobecane

Thanks Simon. I'm a retired big city motorcycle cop. I guess I'm entering my second childhood, but I love fooling with mopeds. I have six now, and all were bought for pocket money after I spied 'em sitting around peoples homes as I drove by.

My latest addition is an '87 FA-50 still in break-in mileage with original tires!! Guy said it would "idle, but not run"....he thought it was the reed valve. Turned out that wasps had built mud nests in the exhaust. So, some clean up of the carb and exhaust, clean fuel and oil, and on the road I went.

We've had it now!

Dadgummit!..NOW we gotta watch our cop jokes or he'll e-mail us a ticket!Well at least you're retired and possibly your sense of humour has returned.WELCOME to the mopeder's mecca,the General Discussion Forum,MNPD!

Re: Souping up a Motobecane

John Custodio /

Iam glad to see other babyboomers on this site.As a teenager in Bermuda in the late 70s we souped up our mobys.Back then performance parts were available.I do remember that the carb was the first thing to go. Then the exhaust, intake and outtake was bored out, 13 tooth sprocket in front 36 or 38 in back,head was also shaved.Keep in mind that a replacement part could be bought,or found at the dump so we could afford to exeperement. I do have a DEllorto 15 that I hope to try but it appears that a 16 or even a 17 may be better. Which manifold is better for speed,anyone know why the change in the late 70s. Thanks John p.s. always read good info.

Re: We've had it now!

hahaha.

Re: Souping up a Motobecane

Thanks for the tips. I've heard that replacing the stock head gasket with a beer or soda can shaped, cut and hammered flat has the same effect as shaving.

Anyone try this down and dirty trick?

Re: Souping up a Motobecane

John Custodio /

mnpd.I also read about the soda can gasket,safer way.Ibelieve same article sugested using a carb from a tomos 70 speed kit.Can anyone verify that, if so what kind of carb is it.John

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