carb problems

[fast94tracer]

well even tho i have float problems
there is a new problem
i have good bottom end i can even give it wot but when the revs start to climb it cuts out totaly but then i can back out of the throttle and it starts to run again

what could this be caused by

the person i bought it from said he put a larger carb on it so im wondering if it jetted way to rich

[super90]

Yes, most likely too rich. What does your plug look like? If its rich lower the needle clip a couple notches and mess with the air and fuel screws. Try turning the air screw out a couple turns and putting the fuel in a couple and just fine tune it with the screws. If that dosent help you may need to go down a few jet sizes.

[fast94tracer]

well i dropped the needle down 2 notches and it runs alot better but it still floods the engine out but know i have experianced the breaking up in the high revs

[iowarotax]

My 85R was doing the same thing, and it turned out to be the air-filter was clogged with too much oil. Now it screams. Also, check the pipe and silencer for being full of carbon. My 84R had that problem and had no top end. After I cooked the pipe, it ran great.

[fast94tracer]

well at least its more ridable right now

[fast94tracer]

get this i finally got my carb in the mail and compared the carb that is on my bike to the one i recieved and the one i just got is so small compared to the one on my bike the motor side of the new carb can almost fit inside the old one

so i tried putting the new one on and when i started it i had to hold the throttle half way open just to keep it running and it wouldnt rev for nothing the carb i recieved has a 126 jet in it and my old one has a 260 in it but i got it to run beautifully with the old carb but i just still have that float problem

what could be wrong with the new carb its acting very funny its like its getting way too much fuel

[super90]

Make sure your float is not sticking. A good carb rebuild kit would help probably, also try going down size by size until its perfect. If the raising the needle clip did help you should go down to a a couple sizes from the 260. And you did say it ran better when you raised the needle clip right?

[fast94tracer]

yes it did but whats pissing me off is that i purchased a stock 250r carb and it wont run when its on there

also how do figure out what floats i need to buy for my unknown carb
all i know is its a mikuni carb and it has the shafts inside that the floas ride on since they are two seperate floats

[super90]

Is there any mods done to the engine that you know of? That could be one reason the stock carb is lacking the fuel, or its jetted way off. But it sounds like the larger carb would be the best. The little float valve could be sticking inside the carb letting too much fuel in also. Is there any gas coming out of the overflow when it starts to bog out? I bet a good cleaning and rebuild kit (around 12.00) would help you out alot. If it still bogs down then its not the float, and jetting down would stop it from flooding out.

[fast94tracer]

well today i went riding all day and i never had to turn my fuel off it was great no overflowing at all

it ran great till the engine got to hot and wouldnt run but as soon as it cooled down it ran great