Been trying to help with a 2010 RT. Bike idles fine and runs ok at part throttle. If you try to accelerate, the bike really runs poorly until about 5000 RPM and then the bike seems to run ok.
He has replaced the spark plugs and coils with no improvement. He has ran a few tanks of fuel since the problem started so I dont think it's bad fuel.
I have disconnected the o2 sensors and knock sensors but no change. I also did a compression check, 160 lbs on both sides.
No codes from the GS911.
With no failure codes, no history of when the problem started, & not being able to ride the bike this is going to be a difficult diagnosis over the internet.
Let's start by having you explain the term -- bike really runs poorly
-- Exactly what is it doing? Any popping or farting in the exhaust or back into the intake
There is some popping on decel, but it has an Akra can on it and has always done some. It really isn't a miss, more of a stumble and just a lack of power.
Some history of when the problem started & IF it came on slowly or all at once could be a big help in understanding the problem. Anything, like a service just done prior, or a fuel fill up just prior, or riding in heavy rain just prior, or accessory just added, or anything on the bike disturbed just prior, etc?
It's been serviced regularly but not before the problem cropped up. He doesn't ride in the rain and it's ran through a few tanks of fuel since it stated acting up.
Were all 4 coils replaced? It has some ear marks of a bad lower coil.
It really acts like a bad coil, I've experienced that before. However, when I take a temperature reading from the header pipes they are equal. He did replace all four coils with new coils.
I know that you ran a compression test but that doesn't always tell the story-- Can you run a home type leak down test (with all valves on a cylinder closed blow about 75-100 lbs compressed air into the cylinder & see how much air comes out where). See if it sounds equal on each sides.
I'll give it a shot.
Is the bike stock (ie no added fuel controllers, or added intake temp sensor spoofer, etc?
Outside of the Akra it's stock.
Has the valve lash been checked?
I checked the valve lash, it's within spec.
Is the cam timing close?
Need to check.
I guess baring more specific info on the problem & when it started you might try a FPC by-pass & temporarily run full 12-14 volts to the fuel pump (basically eliminate the FPC).
Need to check.
Is the problem apparent when revving the engine sitting still?
Nope, only under load.
Any chance that you can do a GS-911 data trap during the time that it is acting up-- Actual sensor & fuel control data during the time that it is acting up could go a long way towards finding the problem.
It's a RT so I'll have to see if I can rig something up.
Thanks for the response!