Post by wotavidone on Jan 28, 2006 18:41:53 GMT -5
Heeelp! Just bought a 1978 SR500. Allegedly 18,000km since total rebuild. 10:1 Wiseco piston. Premium unleaded plus Flashlube. 15 teeth front, 42 teeth rear. Felt good on backstreet test ride. Parted with my $2500 and took her home on a trailer. Highway riding poor. Surges badly around 4000, smooths out again at 5000. Plug sooty looking. Fitted new plug and air filter.
Cleaned carby. Lifted carby needle one notch (richer) made it worse - plug sootier. Dropped carby needle one notch (leaner) got rid of most surging, almost a pleasure at 4000 rpm. Slight pinging evident when rolling throttle on from 4000 in top. Can be controlled by gentle use of the twist grip. Disaster when carrying passenger. Pings badly when attempting any sort of acceleration in top. Any ideas? Is 10:1 a hopeless number on pump fuel? Hard to buy avgas here. (Port Pirie, South Australia) Is the 50 thou off the slide a worthwhile mod? Is it an appropriate mod for my particular problem? Considering putting in a shim under the e-clip on the needle, sort of get a halfway setting between two notches. Could probably score a TT500 carby. I believe them a lot simpler? Would it fit in the same space, same diameter rubbers, etc? An afterthought, could adjusting the air screw for the pilot jet help? Haven't touched it yet.
Current thinking is dear lord what have I done? ER-5 kwaka doesn't look quite as boring anymore.
Gotta admit its a headturner. Got a nod from a Harley rider yesterday, though he might have just got hit in theye by a bug.
Any advice greatly appreciated.
Cleaned carby. Lifted carby needle one notch (richer) made it worse - plug sootier. Dropped carby needle one notch (leaner) got rid of most surging, almost a pleasure at 4000 rpm. Slight pinging evident when rolling throttle on from 4000 in top. Can be controlled by gentle use of the twist grip. Disaster when carrying passenger. Pings badly when attempting any sort of acceleration in top. Any ideas? Is 10:1 a hopeless number on pump fuel? Hard to buy avgas here. (Port Pirie, South Australia) Is the 50 thou off the slide a worthwhile mod? Is it an appropriate mod for my particular problem? Considering putting in a shim under the e-clip on the needle, sort of get a halfway setting between two notches. Could probably score a TT500 carby. I believe them a lot simpler? Would it fit in the same space, same diameter rubbers, etc? An afterthought, could adjusting the air screw for the pilot jet help? Haven't touched it yet.
Current thinking is dear lord what have I done? ER-5 kwaka doesn't look quite as boring anymore.
Gotta admit its a headturner. Got a nod from a Harley rider yesterday, though he might have just got hit in theye by a bug.
Any advice greatly appreciated.