Motorcycle Repair: Engine Trouble, yamaha xt225, carbuerator

Question
I have a 2001 Yamaha XT225.  It has sat for almost 2 years.  I run it occassionally, but have not gone riding for more than a couple of minutes here and there.  Last year I was going to take it for a ride, but it was running really rough.  I took the carbuerator in to have it cleaned up.  When I put it back on my bike it ran really good for a minute or so and then started running really rough.  I think it sucked some bad gas into the carb or something.  When I put the carb back on I didn't clean the gas tank out.  This year I decided to try and get it running well.  Now that you know the history of its recent problems, here is what it does now.  It starts right up with the choke on.  If I give it any gas it bogs up but with more throttle it clears out and runs fast.  If I let it warm up for a while it idles very nice and it stays idling when I shut off the choke.  Now that the engine has warmed up, as soon as I give it any gas it almost kills the engine and if I give it more throttle it does kill the engine.  What do you think is causing this behavior?  How can I fix it?  

Thanks!
Jonathan

jckampfer@hotmail.com

Answer
Hi Jonathan,

I suspect the fuel system will need to be inspected and thoroughly cleaned.

The old fuel contaminated the clean carburetor the instant fuel reached the float bowl.

Fuel circuit passageways are likely obstructed causing the engine bogging symptoms.

Ensure the air intake & air filter are clean and in good condition.

I'll send tech files to your email. Review the files and consider cleaning the carbs and related parts.

Respectfully,
Mark Shively