new problem w/motobecane

Ok i got my Motobecane running where it stays running w/out choke....I'm thinking it may not be the seals because i sprayed starting fluid all over the place. around the clutch and around the magneto side ...all around the carb and it doesnt race when i do any of that...i got it so i can run it down the road about 1/2 throttle, as soon as i give it full throttle it bogs down like it's leaning out. Any idea's?

Re: new problem w/motobecane

Have you checked the petcock for flow? A weak fuel flow would cause a problem like that. Of course there could be other things...If it has been sitting a while, a thorough carb and fuel tank cleaning are in order. An in-line fuel filter wouldn't be a bad idea.

Re: new problem w/motobecane

The choke is not a choke, it is an enrichener (it adds gas rather then cutting air)

-check the main jet for blockage

-check the float level, it should be about half way up the needle I think

-get a little speed going, then at the point when it start to "bog down" pull the "choke" (providing more gas) and see if it gives you a boost. play with the throttle and choke while riding and you should be able to figure if there is a problem with the fuel mix, and what you need to do to correct it.

Re: new problem w/motobecane

If a give it a bit of choke it runs normal when i am at full throttle. so what does this mean? i have cleaned the carb several times and blew it out with compressed air

Re: new problem w/motobecane

It means your engine is starving for gas at WOT. Could be an incorrect float level (as mentioned), a clogged passageway in the carb, a jetting issue, a fuel flow issue...

Just for a start you might want to try adding some fuel treatment to your mix. I toss in about an ounce of that stuff in my Moby from time to time. It does improve performance.

Re: new problem w/motobecane

🇮🇹💦 Of the Loin /

i know mobys arent too finicky about jets, but check your jet just to be safe.

I ran a gurtner 58 and that worked great

Re: new problem w/motobecane

I'm thinking it might be a float issue....how does one get more gas into the float chamber...i did take the jet out and cleaned it really good....

Re: new problem w/motobecane

The float height can be set by CAREFULLY raising (or lowering) the float on the central needle. However, you can only do this if the float is plastic (some are brass and the needle is soldered in place). So, if you have the plastic float, which is most likely the case, fix the needle in a vice with about an 8th of an inch gap and push the plastic float until you have it at the correct height. If your goal is to have more fuel in the float bowl, then you will need to push the float towards the pointy side of the needle. When setting the height, make sure that the pointy side of the needle seats properly under the cap of the float bowl. And be aware that moving the float will require some force; but be careful not to be too forceful and bend the needle when doing this. If you mess things up, new floats are about $10-15 (I think).

Re: new problem w/motobecane

The key to this procedure is to not damage the pointy side of the needle. You might want to protect it somehow if you are putting it into a vice.

Re: new problem w/motobecane

might be running lean if you don't have the airbox in place. It has been my experience that the airfilter assembly has the effect of making the engine run richer at higher engine speeds. There is also a filter where the fuel enters the carb that you might want to check for blockage.

Re: new problem w/motobecane

And don't rule out the spark plug either. Get a couple different types that go through the heat range. I'm not up on my plug numbers, but there are endless threads on the subject. There is also a really cool idea out there called side gapping that might be worth a try. Do a search on the subject.

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