Motorcycle Repair: Poor Performance, yamaha xt 225, vacuum leaks

Question
I have been working on a 97 Yamaha XT 225 for a couple of months now, I rebuilt the engine and have restored most of the bike to original stock condition.  I have the bike running now, but it has poor performance when I hit the gas...  It idels well, when I doa quick rev of te engine the RPMs climb then it dropped off 2 -3 back fires then stops.  Its a factory seal carbarator ao there are no exterior adjustments I can see.  Also, when it runs, its leaks fuel from the air intake, not sure what to do.  Any suggestions?

DJ

Answer
Hi DJ,

Providing the valve clearances and compression are within service limtis, and cam timing is set properly, I suspect the carburetors will need one or more of the following: cleaned, synchronized, jetted.

Check cylinder compression and perform a leak-down test to verify the sealing properties of the combustion chamber (condition of the engine).

Check and adjust valve clearances.

Read the appearance of the Spark plugs to know what occurring during the combustion process. The appearance of the plugs will help determine which tuning adjustments are neccessary with the carburetors.

Check for vacuum leaks.

The carbs has tamper plugs covering adjustment screws.


If you're still experiencing problems or cannot perform the above tasks, have a local tech perform the work.

Visit the following XT225 Rider's Group website:

www.neatknacks.com/ubb/ultimatebb.php

Respectfully,
Mark Shively