300ex wont idle after warmed up

[XR200R]

if i set idle its fine when starting it up, rev it a few times or ride it and it returns to rev higher. i adjusted it once warm and it wont idle if i let off gas.

this is a PITA for trail riding.

carb was just cleaned. any tips?

[smr]

If I had to guess I would say one of two things.

Timing chain streched (most likely) It just bad enough that when it gets warming up is throws the timing off just a little.

Valve clearance...I set both intake and exhuast at .04

good luck

[XR200R]

ive never heard of timing chain not causing bikes idle but yeah motor is 100% new timing chain, .060 over. and valves set correctly. its a carb issue but i cant get it dialed.

[XR200R]

putting on a new exhaust 1st
putting a uni filter 2nd
in the mean time ill check to see how many turns the airfuel screw is out.

anyone else got any idea?

[QuadCobbler]

If ur so sure it is the carb, than why dont you just pull a carb off something else you own and see if that is the problem. If the problem is still there than its prety obvious the carb is not the problem.

[XR200R]

i dont have another carb lol.

[QuadCobbler]

If you have another carb from any thing around 250 to 400CC it should fit and work. A 400ex carb is a little tight on the intake boot but still fits. Some people have soaked them in hot water to soften them up. Mine fit in with no problem, it was the tube to the air box I had trouble with.

[XR200R]

I got a tiny carb on my xr200 but im not taking that apart. im planing to buy a 400ex carb. im not too worried about fitment of the intake tube...i run a custom alum airbox and just run 3" auto radiator hose.

ill take it apart again its not bad, i set it up my plastics are held on by my gas tank bolts and my tank has 18" of fuel line hose rapped around carb the long way so you can still run the bike and get to the other stuff below.

i had an extra 300ex carb but gave it to my friend alone with a toasted 300 motor in million peices.

[QuadCobbler]

Have you tried running the bike with out the extra long fuel line? If the line is getting hot it may be causing your problem.

[XR200R]

no i havent, its a race set up my buddy used on his other 300's and they all idled fine.

it loops and flows down great. i tried making a tool to get to the air/fuel screw but wow is it tight. better to just take it off and spill some fuel.

just funny in runs perfect but wont idle right. i am planing a 400ex carb. ill tear into it tonight and tomorrow.