At 6000 RPM (or thereabouts) I'm getting a loud "racing" noise from the front of the engine, coupled with a seeming loss of power. I just changed the exhaust without changing the gaskets. Could this be a leak? Or is it something perhaps more sinister?
Bike is totally fine/performs normally up to that engine speed.
The noise could be bad gaskets.A set is only like $10.The loss of power is probably a jetting issue.What jets did you rejet with after the exhaust upgrade?
The loss of power might just be me instinctively backing off throttle when hearing the noise. These jets have been in the bike a while now; if they were an issue I'd have known it.
I've done enough work on this bike the past few weeks. I'm just going to take it to the shop and have them deal with it.
Anytime you upgrade the exhaust or air filter,it changes the flow through the engine and changes the air fuel ratio.Rejetting keeps everything running correctly.Your power loss issue seems to be a lean condition on top end due to a free flowing exhaust.If you have the factory exhaust and air filter,it maybe you letting up when hearing the noise.
Quote from: ben2go on May 20, 2011, 08:37:29 PM
Anytime you upgrade the exhaust or air filter,it changes the flow through the engine and changes the air fuel ratio.Rejetting keeps everything running correctly.Your power loss issue seems to be a lean condition on top end due to a free flowing exhaust.If you have the factory exhaust and air filter,it maybe you letting up when hearing the noise.
The exhaust was removed to paint the headers, not install anything new. I'd previously had a Yoshi slip on and jets done by the shop; their jetting was spot on. But by the above logic wouldn't a leaking gasket also change flow/impact power?
What I'm detecting as (maybe) power loss could just be a sudden drop in back pressure from the exhaust blowing by a faulty/old gasket. I've ordered a new set of gaskets off the bay. Are these the right ones: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=160581228529&viewitem=&sspagename=STRK%3AMEWNX%3AIT (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=160581228529&viewitem=&sspagename=STRK%3AMEWNX%3AIT)
Christmas...I guess I'm gonna be turning a wrench on this thing again.
Quote from: Pelikan on May 20, 2011, 08:51:51 PM
Quote from: ben2go on May 20, 2011, 08:37:29 PM
Anytime you upgrade the exhaust or air filter,it changes the flow through the engine and changes the air fuel ratio.Rejetting keeps everything running correctly.Your power loss issue seems to be a lean condition on top end due to a free flowing exhaust.If you have the factory exhaust and air filter,it maybe you letting up when hearing the noise.
The exhaust was removed to paint the headers, not install anything new. I'd previously had a Yoshi slip on and jets done by the shop; their jetting was spot on. But by the above logic wouldn't a leaking gasket also change flow/impact power?
What I'm detecting as (maybe) power loss could just be a sudden drop in back pressure from the exhaust blowing by a faulty/old gasket. I've ordered a new set of gaskets off the bay. Are these the right ones: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=160581228529&viewitem=&sspagename=STRK%3AMEWNX%3AIT (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=160581228529&viewitem=&sspagename=STRK%3AMEWNX%3AIT)
Christmas...I guess I'm gonna be turning a wrench on this thing again.
A bad enough header leak could cause a loss in power,but not a dramatic loss.Back pressure in a four stroke engine kills power.It choke the engine and will not allow it to flow freely.