My bike is finally running, great, but...
I had trouble with the exhaust valve shims being way off. I got that fixed. When I first ran the bike it was great. Now, after about 15 miles of puttering while I adjust things, there's a knock when I accelerate. Not always, just with hard acceleration, and it's not all that noticable. I thought it was a loose bolt at first. Now I think it's coming from the valve cover.
When I did the shims I checked again and again, and it was within spec. The high end of spec, but within spec. I had blown the oil out of the shim bucket with compressed air, but I am wondering if I got Buddha's oil float anyway.
Am I right that this is probably loose shim related valve knock? Is this somthing I can live with, or do I need to worry about it?
May sound obvious but you should take the valve cover back off an recheck your valve clearances. If the knock wasn't there b4, then somethings off or been disturbed.
Sounds like gas knock if only when accelerating after engine is hot, could be you have some compression now. If your using regular gas try a tank of premium just to see if it goes away. Can't remember what year bike and how many miles you have on it. Could be a different grade of oil coild get you back to regular gas if that's the problem.
start by rechecking valve clearances. Be sure the engine is cold when you do this.
+1 GSJack and detonation. Rule this out with premium unleaded.
certain model years have a problem (not serious) with excessive end play in the cam shafts. Makes a knocking sound from the valve cover area. Search this forum for more discussion. I forget the fix.
2004 with about 14k miles.
It was running like crap when I got it, so I can't really compare now to then, which is why I hit you guys up.
This is stupid, but I think you're totally right about the gas - didn't even think about it... My last bike was a 1979 - I could drink a 5th and pee in the tank and it would run. I will toss some octane boost in there, and then hit premium when I fill back up. The valve knock didn't make sense to me - I triple checked those clearances.
Nice to be riding again... though last night was 40 degrees.
Quote from: lawman on March 26, 2009, 10:47:33 AM
2004 with about 14k miles.
It was running like crap when I got it, so I can't really compare now to then, which is why I hit you guys up.
This is stupid, but I think you're totally right about the gas - didn't even think about it... My last bike was a 1979 - I could drink a 5th and pee in the tank and it would run. I will toss some octane boost in there, and then hit premium when I fill back up. The valve knock didn't make sense to me - I triple checked those clearances.
Nice to be riding again... though last night was 40 degrees.
Just FYI, GS is not far off. The engine design is from the 70s...
Perhaps, but the carb was updated in 2001, the 04 GS500F has a TPS update, and low octane gas is a known problem for these.
im not understanding how 87 octane gas would be the problem. thats what this low compression motor is set to run on from the factory.