tomos speed cuts out near top speed

i have a 1995 lx with airsal 27 tooth sproclet techno estroil 15/15l carb uni filter and ported intake and exhaust. i was riding to day about 90 degrees outside and i reached my top speed witch is around the speedo once so passed 40 at zero again. after that, i went into my friends house and when i went back to ride it it would get to 35-40 and cut off then accelerate then decelrate in a very jerky way. what is the probelm help. is it the heat is it seized?

Re: tomos speed cuts out near top speed

pull the head and see what's up.

Although it sounds more like a carburation or electrical problem than a mechanical one, when you push these little engines to the limit you gotta stay ontop of things.

Heat makes air thinner so it will run richer at 90F than at 50F. Thats no problem.

But humidity in the air means the air carries more water vapor. That vapor crowds out oxygen so the carb runs leaner. (air + water + gasoline instead of air + gasoline.)

If you are riding on the edge of a too-lean mix and the air changes to very humid, jetting has to be adjusted..

Electrical.. who knows.. maybe a condenser is dying. maybe the points are floating..

Re: tomos speed cuts out near top speed

thanks it just sort of gave up and the comprssion is great.

Re: tomos speed cuts out near top speed

an i get tons of shock becuae i got shocked when i plud the cap of the spark plug

Re: tomos speed cuts out near top speed

after re-reading the way it was acting.. jerky .. like slow to fast and slow again, i'm thinking it could even be a drive problem, like a clutch or belt is slipping or something.

i bet that after you give it all a good looking over something will be obvious.

Re: tomos speed cuts out near top speed

alright so its probaly tranny probelms

Re: tomos speed cuts out near top speed

if its a multi speed chain drive, then no.. i wouldnt suspect the trans.. maybe the clutch. If it is a drive problem something's slipping. Thats a big 'IF'.

You would know it if you lost a gear or a bearing.. from the noise mostly. But clutches usually dont just go away without warning. They work their way up to it over time.

in my opinion it's carburation. something like a piece of junk got sucked into the carb's main jet, partially blocking it This would cause erratic carburation and erratic top speed.

Electrical problems a bit more rare so thats farther down the list.. although examining and testing this bike with a brand new spark plug will not hurt.

you gotta get down and examine everything. Whatever it is can be fixed, but not until you find it.

Re: tomos speed cuts out near top speed

ok i plan to clean the carb today i do have do surface rust in my tank so that might be a problem in the carb

Re: tomos speed cuts out near top speed

Make sure no extra air is coming in via the oil injection or the intake box. Breaking apart the carb and checking the float and filter on the gas inflow can't hurt, either. Make sure your main jet is clean.

Ben

Re: tomos speed cuts out near top speed

well i did all of this and it was the sparkplug it was fouled

Re: tomos speed cuts out near top speed

got it fixed? cool..

you have any idea what fouled the plug?

Re: tomos speed cuts out near top speed

well bj at handy bikes saifd that it was becuase of the humidity and vapor build up in the tank

Re: tomos speed cuts out near top speed

it could be because oil got into the condensor and points i had something like that and thats what the problem was

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