QuestionMy Xs650 has some problems,when i'm in the road sometimes dosent take the gas or better to say cuts the gas and sometimes makes like a gunshot ? Where the problem can be ?
P.S sorry for my bad English.
AnswerBardh, I am not a Yamaha expert, however I do know that they were made for many years and went through a number of changes. You didn't mention the year of your bike, so I can only make general comments about dying and backfiring issues.
The compression should be checked and verified as being near factory specifications. If one side is low, adjust the valve clearances to specifications and test compression again.
The carburetors should be cleaned and checked for signs of contamination by rust, dirt or moisture. The float levels should be adjusted to specifications, which probably varied through the years of production. I believe that there are several XS650 forums, perhaps on Yahoo or elsewhere. The carburetors have large rubber diaphragms on the slides. If the rubber is torn or has the smallest hole, the carburetor will not function off-idle.
The ignition timing must be tested and adjusted so the points just open at the F mark on the rotor/stator markings. If the engine is later model, then the ignition may be electronic and not adjustable. You could have a bad spark plug/spark plug cap or coil, however.
Check the intake manifolds for air leaks.
http://www.cmsnl.com/yamaha-xs650d-1977-1979_model8639/partslist/B-03.html#resul #2 and #3
As you can see there are many possible sources for your problems. Start with a basic tune-up.
Bill Silver
