[heimy]

I have an '87 TW200 that doesn't like to idle when cold. The carb has been taken apart and cleaned, new fuel filter installed, tank has been flushed, valve clearances are good and checks out mechanically, new spark plug and air filter.

Most times when I start it, it runs really rough, will stall if you throttle it. Sometimes the rpms will go up and down a few times. Usually it will sort itself out and run properly after about 15 minutes, but once in a while it stalls and won't restart. There is fuel going to the carb. I thought it might have a tank venting issue, but does the same with the gas cap off.

After riding for 5 or 6 miles it will often start running rough again for several minutes and then sort itself out and run fine for the rest of the ride.

It starts fine when warm, and occassionally it will fire right up and run smooth when cold.

Anybody had this type of issue?

Any suggestions would be appreciated.

 

[Xracer]

If you have not all ready done so.Check the intake manifold and carb/airbox boot for any cracks.Even a small one can cause problems.Also check the carb/airbox boot for shrinkage that can cause a gap that lets air in.

 

[rockiedog2]

If you have not all ready done so.Check the intake manifold and carb/airbox boot for any cracks.Even a small one can cause problems.Also check the carb/airbox boot for shrinkage that can cause a gap that lets air in.

What Xracer said plus when you had the carb down did you check that the choke is working properly? The rpm varying up/down often is an indication of lean/varying mixture. Is it possible that your choke is somehow intermittent; I'm not familiar with that particular carb. From your description of after several miles it gets rough again makes me wonder if you may have more than one problem working there...lean when cold and some other intermittent feed problem after it's warmed up

 

[heimy]

I got the bike back from the mechanic today. Turned out to be the CDI box. Runs great now.