katanamangler
Registered user
It's not as it sounds. This post goes out to the technical gurus of the all things oilhead. Please bare with me as I tell the story.
I have been chasing a problem with my 03 1150 GSA ( 32K on the clock) since I bought it about a month ago. The symptom was that once up to working temperature it wouldn't pull around 4-5 thousand revs in 5th and sixth gear ( basically under load) MPG were also quite low.
So I changed the stick coils ( ouch) , the plugs, set the valve clearances and changed the fuel filter. I drained the tank and it was as clean as a whistle ( lining intact and no debris) checked the TPS voltage and balanced the throttle bodies.
The bike ran better but the problem was still present. Next I took the injectors off wired them up to a power source and switch and an air line and fired neat injector cleaner through them at about 30psi ( they were clean) the spray pattern was good. But still my problem persisted.
So I had eliminated the obvious Spark issues , fuel supply issues and valve clearance issues. In addition an electronic diagnostic check showed no faults ( thanks Ian)
Another anomaly was a slightly high tick over and the fact that despite no evidence of air leaks I couldn't get the tick over down and and get the a balance even when the BBS were all the way in one side and just a quarter turn out on the other. I got it as low as I could ( 1200) but it smelt like it was running a little rich.
Finally I sprayed AMSoil power foam directly into the throttle bodies while the bike was running and let it soak into the piston crowns and valves for 30 minutes. I then took the bike out for an "Italian tune up" Hallelujah! it pulled freely to the red line all the way through the gears and the stutter under load had gone. But when I returned the the tick over had risen again.
So ( hopefully someone's still listening) my conclusion is that the bike had, over time built up a significant carbon depositing around the valve seats and the piston crowns. The previous owner told me he never rode the bike above 80mph. If the bike was short shifted everywhere and it was still using oil, the lack of spirited riding may have allowed significant build up of carbon deposits on the piston crowns hence the pinking under load when warmed up. I can only surmise that the removal of some of the build up on the valve seats may have allowed the exhaust valves to re-seat slightly making the previous carbon chocked clearance too tight allowing the cylinder to draw air hence the lift in tick over. I'm going to check the valve clearances again and test my theory.
Experienced oilheeds feel free to poke holes in my theory.
I have been chasing a problem with my 03 1150 GSA ( 32K on the clock) since I bought it about a month ago. The symptom was that once up to working temperature it wouldn't pull around 4-5 thousand revs in 5th and sixth gear ( basically under load) MPG were also quite low.
So I changed the stick coils ( ouch) , the plugs, set the valve clearances and changed the fuel filter. I drained the tank and it was as clean as a whistle ( lining intact and no debris) checked the TPS voltage and balanced the throttle bodies.
The bike ran better but the problem was still present. Next I took the injectors off wired them up to a power source and switch and an air line and fired neat injector cleaner through them at about 30psi ( they were clean) the spray pattern was good. But still my problem persisted.
So I had eliminated the obvious Spark issues , fuel supply issues and valve clearance issues. In addition an electronic diagnostic check showed no faults ( thanks Ian)
Another anomaly was a slightly high tick over and the fact that despite no evidence of air leaks I couldn't get the tick over down and and get the a balance even when the BBS were all the way in one side and just a quarter turn out on the other. I got it as low as I could ( 1200) but it smelt like it was running a little rich.
Finally I sprayed AMSoil power foam directly into the throttle bodies while the bike was running and let it soak into the piston crowns and valves for 30 minutes. I then took the bike out for an "Italian tune up" Hallelujah! it pulled freely to the red line all the way through the gears and the stutter under load had gone. But when I returned the the tick over had risen again.
So ( hopefully someone's still listening) my conclusion is that the bike had, over time built up a significant carbon depositing around the valve seats and the piston crowns. The previous owner told me he never rode the bike above 80mph. If the bike was short shifted everywhere and it was still using oil, the lack of spirited riding may have allowed significant build up of carbon deposits on the piston crowns hence the pinking under load when warmed up. I can only surmise that the removal of some of the build up on the valve seats may have allowed the exhaust valves to re-seat slightly making the previous carbon chocked clearance too tight allowing the cylinder to draw air hence the lift in tick over. I'm going to check the valve clearances again and test my theory.
Experienced oilheeds feel free to poke holes in my theory.
