I have a 2002 ST1100. I just bought it a few weeks ago. At highway speed (60 MPH+) it will run OK for about 5 miles and then slowly lose power. I can roll off of the throttle and coast down to about 40 MPH while occasionally downshifting until I am in second gear. At this point I am then able to accelerate back to the 60 MPH + range for a couple of more miles and then this repeats.
I have replaced all 4 spark plugs (correctly gapped) and the fuel filter. I have checked the gas cap vent hose and it is clear. I am able to move air through the gas cap vent valve after a little resistance.
To me this sounds like a fuel delivery problem but I don't know what steps to take next. Fuel pump, carburetors?
Also, in general, while the bike is pretty responsive in the lower gears it seems like the 1100 cc 4v engine should be more powerful that it is.
Can anybody offer me some insight on this?
I have replaced all 4 spark plugs (correctly gapped) and the fuel filter. I have checked the gas cap vent hose and it is clear. I am able to move air through the gas cap vent valve after a little resistance.
To me this sounds like a fuel delivery problem but I don't know what steps to take next. Fuel pump, carburetors?
Also, in general, while the bike is pretty responsive in the lower gears it seems like the 1100 cc 4v engine should be more powerful that it is.
Can anybody offer me some insight on this?