makarushka
Tuned and Synch'ed
UPDATE while a specific problem that would explain all of this has not been found, after the following work the bike runs fine: while troubleshooting the oil leak around the heads (which turned out to be around the CPS and the crossover head oil delivery pipe), they have taken the heads off to check the cams and tappets (which were perfect), checked the IAC valve and all related hoses for contamination, stepper motor operation, changed cam cover o-rings, head gaskets, sealed cylinder head set screws, put everything together, cylinder sync as per the factory, tps reset. no fluid leaks anymore and the bike runs fine. END UPDATE
My 09 G8V has the 68 map and the stock exhaust. Tried the Mistral oval carbon but was not fully happy with how it ran with no fueling correction, so it's back to stock for now. The bike runs pretty smoothly until some 30-40 minutes into the ride, when it gets noticeably rougher and starts vibrating quite a bit more. Anything under 4K in any gear becomes very unpleasant and rough. I'd almost want to say that this SEEMS like some sort of temperature-related correction kicking in and that it's purely fueling-based, but it's only a gut feeling. This happens regardless whether the ride is pure freeway steady speed or hills and mix of gears, etc -- more like a timed effect, somewhere after a 30 minute mark. It seems to happen gradually, too -- not all of a sudden but cumulatively, until you realize the tone of the bike changed, it's boomy and rough.
Anyone might have an idea as to what to check?
The bike has barely over 1200 miles on it. Was fully serviced -- properly, only one idle screw open, sacred screw untouched, etc. -- at 800miles. Then after that service an all-familiar spark plug boot issue came up, and I saw the spark short-circuit to the head on the right cylinder side. I got the new NGK caps and installed them, so that is no longer an issue. Double-checked the throttle body sync and idle balance again just a couple of days ago. Spot-on... Checked and replaced the plugs just in case they got fouled when the bike was running with a cylinder misfiring due to that spark plug cap issue. The TPS is at 4.8; I've reset it but it really did not need it.
Not sure what to do with it. It's not unrideable like this but it is also not something I could live with and be happy in the long run. By various accounts of G8V owners with A5 motors, it does not seem normal either. In its current state -- when it kicks in -- it's reminds me of my V11 Sport when it was tuned badly, and that's saying a lot. Any idea anyone could share I'd very much appreciate...
My 09 G8V has the 68 map and the stock exhaust. Tried the Mistral oval carbon but was not fully happy with how it ran with no fueling correction, so it's back to stock for now. The bike runs pretty smoothly until some 30-40 minutes into the ride, when it gets noticeably rougher and starts vibrating quite a bit more. Anything under 4K in any gear becomes very unpleasant and rough. I'd almost want to say that this SEEMS like some sort of temperature-related correction kicking in and that it's purely fueling-based, but it's only a gut feeling. This happens regardless whether the ride is pure freeway steady speed or hills and mix of gears, etc -- more like a timed effect, somewhere after a 30 minute mark. It seems to happen gradually, too -- not all of a sudden but cumulatively, until you realize the tone of the bike changed, it's boomy and rough.
Anyone might have an idea as to what to check?
The bike has barely over 1200 miles on it. Was fully serviced -- properly, only one idle screw open, sacred screw untouched, etc. -- at 800miles. Then after that service an all-familiar spark plug boot issue came up, and I saw the spark short-circuit to the head on the right cylinder side. I got the new NGK caps and installed them, so that is no longer an issue. Double-checked the throttle body sync and idle balance again just a couple of days ago. Spot-on... Checked and replaced the plugs just in case they got fouled when the bike was running with a cylinder misfiring due to that spark plug cap issue. The TPS is at 4.8; I've reset it but it really did not need it.
Not sure what to do with it. It's not unrideable like this but it is also not something I could live with and be happy in the long run. By various accounts of G8V owners with A5 motors, it does not seem normal either. In its current state -- when it kicks in -- it's reminds me of my V11 Sport when it was tuned badly, and that's saying a lot. Any idea anyone could share I'd very much appreciate...