Hi guys,

I've got an 89 xt600 that I've had for 2 years and haven't been able to get the carb dialed right yet. It's been good enough to ride but at wide open throttle (and close to it) it sputters and hesitates, especially when I have the weight of a passenger. I've tried some slight variations in the main jet, increasing the float level a little, have new boots and can't detect any air leaks. The bike is stock except for the baffles are removed from the factory exhaust.

Should I continue to experiment with the main jet and float level or should I play with needle height? If so would it be the needle on the left or right side? Other adjustments I should consider?

Thanks in advance!

PK

Make sure the secondary carb's butterfly is fully open at wot , or that it isn't going past flat and actually closing too much to restrict airflow . 120 mains in both carbs are what I'm running IIRC , if 125 or 118 in the right carb(secondary) doesn't clean it up then it may be another issue like the pick-up coil or cdi that's giving issue . Could even be the compression is getting low so it can't run efficient up top . I'd do a compression test or leakdown test to see just what the health of the motor is at least .




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Sounds like there is not enough air or fuel at highest load.

Is the air filter an original one or some aftermarket 2-layer thing?
Have you checked with fuel tank lid off?
Extra inline fuel filters?
Fuel pump already bypassed?
Fuel line without any sharp bends?
Did you check the tank (fuel filters inside) and fuel taps for good flow?
Is this the same no matter if the tank is full or near empty?
You have checked the scondary carbs membrane for any wear?
Connector tubes between carbs are fine? Same for tube to inlet boot?

Andy

It may be silly, but have you done the side stand switch, vibration may cause cutout.

Thanks for the tips guys, I'll be back with the bike this weekend and will try your suggestions. I realized that the manual I have is for 1990-95 models. Is there a PDF online of a manual for 1989?

Thanks again,

Peter

It sure sounds like its a rich condition.

Any news?

New air filter cured these symptoms on my bike. I need a new one every 3-4 months cus of the vast amounts of dust in portugal.