QuestionHaving trouble with 1995 cbr 600 . idles great lack of power under load, cleaned carbs completely ,did not touch pilot jets,new plugs,syncronized the carbs, did not change the way it runs. put on a second set of carbs same problem. also the bike once revved stays at 3000 rpm and stays there until the idle screws are turned down. The throttle position sensor if unplugged while the bike is running has no effect on any way of the performance of the bike. Tried a different throttle position sensor and it made no difference as well. I suspect that the spark unit may be bad but I do not know. I just got the bike recently and do not know what has been done to it other than a full exhaust sys, k&n filter. Do not know if it has an ignition advancer. This motorcycle is a race bike and I have checked the wiring and it is in good condition. Any help would be greatly appreciated as I do most of my own repairs and and enjoy doing so.
Thanks E.J. scootjockey@aol.com
AnswerHi EJ,
The description indicates an intake air leak. This could be carbs not seated properly into the manifolds, a split or cracked vacuum hose, or other. "It also is indicative of carburetors out of synchronization. Compare your synchronization level readings with factory service limits."
When cleaning carbs, keep individual carbs together on the brackets. Thoroughly clean each circuit passageway and jet. This includes removing air-fuel screws and cleaning their ports and passageways. I'll send carb files to your email detailing many carb related tasks.
First thing to do is check cylinder compression. This will tell you the sealing properties of combustion chambers (condition of engine). Also perform a leak-down test if necessary.
Read the spark plugs. Their colors and conditions explain what's going on with the combustion process and air-fuel mixtures.
Check for the obvious such as throttle and choke cable routing, unplugged vacuum ports, etc...
The problem is not electrical.
Respectfully,
Mark Shively
