Kawasaki Motorcycle Forums banner

exhaust butterfly valve

6K views 3 replies 2 participants last post by  Ben-in-Brazil 
#1 · (Edited)
Hi guys, originally i thought that disconecting the cables would keep the valve open, but it doesn't, it keeps the valve almost closed. So then i opened the valve all the way open by some twisting and bending of metal. The diffrence was crap low rpm power, was horrible, so, i put the cables back on, and hey presto, power came back, more torque and a smoother running engine. When the valve was almost always closed it felt better than always open, but fell on its feet because the gases couldn`t escape after 5,500 rpm, making it feel like shite, had loads of torque because of the back pressure/SCAVENGING effect down low but high rpm failed. That valve is there for a very good reason, so personally i would leave it well alone or buy the akra slip on with the valve. In England the slip on or muffler is called a silencer for a reason, to serve the purpose of silencing noise, not emissions, as many are led to believe. The CAT, silencer and valve all have different applications, that work in perfect harmony in stock form, for stock fueling.
 
#2 ·
Ay Ben I have a 2008 zx6r had a starting problem but look like was the battery but I still have a clicking sound by the starter selanoid,what's up with that? But the problem you had with the valve did it didn't make you past certain Rpms? Like something was stoping it ? Because that's the problem I have like I getting high revs .
Mines ain't goin past like 8000rpms
 
#4 · (Edited)
Hi there, sorry I can`t help you with that one, is it still doing that? I never had a problem like that. Basically with the valve held open all the time, it felt like the engine had weak, poor power delivery at low rpm`s, but would be totally fine above 8,000rpm with possibly a bit extra power up top, but it`s not worth it in my opinion because of the effect on power delivery. Hope you get that problem sorted out.

Check your exhaust valve to make sure it`s opening and closing correctly. Maybe the problem is because the valve is stuck in the closed position, which might explain the high revs problem.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top