Honda XR200 running a bit rough

[rocketman1]

My Honda XR200 1998 is running a bit rough, idle speed changes all the time and it backfires and splutters a bit on overrun, and some times speeds up while running in neutral for no apparent reason? otherwise starts and runs well.
It goes well when going faster, its only when going slower and idling that it occurs.
My mate reckons it could be a air leak in the carby, does any one have any ideas. I took the bowl of the carby and it had a small quantity of dirty water in it, I thought that would cure the problem, is going a bit better since I cleaned that up, but still not the best.I have cleaned the fuel tank out.The bike has a new timing chain.

[xwhatsit]

This is what my bike was doing, and I put that down to a cracked head causing air leaks. The backfires and splutters is something you get when it's a bit lean, so air may be leaking somewhere. Would exhaust cause this? Check where the exhaust headers connect to the cylinder head, whether there's any corrosion around there, I know a guy with a scooter who had problems like that. I see it's a recent model... are they anything like the early XRs? They seem to have a reputation for cracked heads, which might cause those symptoms. From seeing pictures the XR250 engine is very close to the XR200 engine, unless I'm confused.

One thing I had, was when the wind blew, the idle speed would change, until the wind stopped. I thought this might have something to do with airflow fucking around the air leak...

Anyway, smarter people with more brains than me on this forum will be able to put you right, I'm sure.

[kro]

check the inlet manifold rubber for cracks, or leaks. I have seen the same thing on other XR's, and this was the biggest culprit.

[T.W.R]

unless I'm confused.

your confused

check the inlet manifold rubber for cracks, or leaks. I have seen the same thing on other XR's, and this was the biggest culprit.

What Kro said

get the engine running and then with a water sprayer set on a fine mist spray around the inlet manifold area and you'll see where the mist is being drawn into any cracks or gaps. Could be a simple as a loose manifold or could be hair-line cracks in the manifold itself.

[merv]

You said you cleaned the bowl of the carb and found cruddy water in it so that is a bit of a tell tale. Did you take the carb right off and clean it properly because it sounds like you might have a bit of crud in your pilot jet. The running on and backfiring is a symptom of running too lean with throttle closed, so that's my guess give it another good clean out. In XR speak a 1998 is a young one so unless you've thrashed the shit out of it it should last about another 10 years.

[Ixion]

Sounds like an air leak, as others have said. But, did you clean the tap out ? And throw a cupfull of meths in the tank.

[rocketman1]

thanks mate I did that, cleaned the pilot jet out , there was this dirty crud around the the brass jet, and the two little bottom holes were blocked, it seems to be idling alot better now, but I havent taken it for a good run yet , thanks for the help.
Cheers Rocketman1

[merv]

Good one I guessed that's all it would be because little goes wrong with those engines especially a young one like yours.