Motorcycle Repair/1983 XL250r

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Question
I bought a 83 xl250r for harescrambles but am having problems with it. Bike has a bad miss when you apply throttle. I have installed a new carb, new coil, wire and plug boot as well as the plug and I still have this problem. I am very confused and don't know what else to try. Any help you shed on my problem I would be grateful.

Answer
Jimmy, did your "new carb" match the one that came on the bike or was it an aftermarket carburetor that fits the bike? Does it have a stock cam?

If the exhaust has been changed and/or the intake system altered from the factory installed parts, then you can expect to have to rejet the carburetor and/or change the needle clip position to get it to perform properly.

This assumes that you have good compression, no manifold leaks and a good piston/ring seal in the cylinder.

Some carbs have an accelerator pump to help part throttle flat spots. If yours doesn't then I would get a batch of main jets and go up one size at a time to see how it responds. Once you get it to pull full-throttle, then you can fine-tune the mid-range by moving the needle up and down using the clip positions.

Bill Silver

Motorcycle Repair

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Bill Silver

Expertise

Need help with vintage Hondas from the 1960s? I am an expert with 250-305cc bikes in particular and most all of the other pre-91 models, in general. I do NOT claim to have a great deal of experience on Gold Wings, Cruisers, ATC/ATVs and dirt bikes.

Experience

I have owned/ridden/maintained Honda motorcycles for 35 years. I have written five books on Honda repairs and collecting. I was a service manager for two Honda shops back in the 1980s.

Organizations
VJMC (Vintage Japanese Motorcycle Club) of North America

Publications
VJMC newsletter, as editor for two years and as contributing editor currently.

Education/Credentials
3 years auto shop in high school, teacher's aide in Automotive Technology in Jr. College, Diesel mechanic course in college, self-taught mechanic and automotive writer.

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