Floats too high??

[corey]

My bike idles great. The other day I made a synch tool out of bottles, vacuum line and motoroil. Really works! Under five bucks, can't be beat.

Anyway, it screams good too.. well, after about 3500 rpms. Under that RPM and under any amount of load the thing pops and stutters out the carbs and pipes. Its done this a bit since I last set the float levels, but the temperature outside was, of course, warmer and I think the bike could handle a richer mixture better.

So here's my hypothesis: the floats are too high, and since the weather is colder, the extra fuel bogs the bike down. When you crack the throttle, however, the mains take over and the full amount of gas can be used. Also, when the bike warms up in warmer temperatures, it can deal use the extra gas. But now since its cold already, the bike can't handle the rich mixture even with the motor warm.

Does this make sense? The only thing that makes me doubt this idea is that my plugs aren't really black... just about the right shade of tan. Well, now that I think about it, maybe a bit toward the dark side.

I would just go out and try adjusting my floats, but I fought like hell to keep the floats from leaking last time and now I'm afraid to mess with them!

[Tdog]

Pilots

Hi Corey,
The pilot circuit is probably lean. Try cracking the mixture screws out a quarter to half turn more before you yank the carbs off again.
Regards,
T

[corey]

I've played with those some, and I wasn't sure what I was doing. Perhaps I'll perform Ken's pilot screw tech now that I can adequately synch the carbs. Thanks!

[oseaghdha]

My bike idles great. The other day I made a synch tool out of bottles, vacuum line and motoroil. Really works! Under five bucks, can't be beat.

Anyway, it screams good too.. well, after about 3500 rpms. Under that RPM and under any amount of load the thing pops and stutters out the carbs and pipes. Its done this a bit since I last set the float levels, but the temperature outside was, of course, warmer and I think the bike could handle a richer mixture better.

So here's my hypothesis: the floats are too high, and since the weather is colder, the extra fuel bogs the bike down. When you crack the throttle, however, the mains take over and the full amount of gas can be used. Also, when the bike warms up in warmer temperatures, it can deal use the extra gas. But now since its cold already, the bike can't handle the rich mixture even with the motor warm.

Does this make sense? The only thing that makes me doubt this idea is that my plugs aren't really black... just about the right shade of tan. Well, now that I think about it, maybe a bit toward the dark side.

I would just go out and try adjusting my floats, but I fought like hell to keep the floats from leaking last time and now I'm afraid to mess with them!

Actually, it's the other way round. Cold air has more oxygen due to the density being higher. If it runs better when hot outside, then you are lean when it's cold. Try opening the idle screws a quarter turn at a time to see if it helps.

This is a good tuning guide: http://www.factorypro.com/tech_tunin...m_engines.html

[egsols]

Hey Corey,

When you say you mave have set the floats too high, you do realize that, the higher the number, i.e. for a 79 going from stock 25.7mm to say 27mm is actually leaning the carbs.

[corey]

Right... I was referring to higher when all the bike. I'll try the screws first, see how that goes... thanks agian!~