Timbone
Well-Known Member
Was cruising into work a few mornings ago and while climbing a short steep hill I suddenly lost power and the engine would no longer run, forcing me to pedal in the final 4 miles.
Before attempting the return ride, I re torqued the head bolts (they were a bit loose) and checked the spark plug for gap. For about 3 miles, I kept working to get things running, checking every system of the bike. Electrics were good. Throttle cable was operating nicely and the jet was clean. No problems with the choke. But by this time, I had noticed blowback from the cylinder head.
Finally, I removed the head. Bam! Saw the problem: aluminum gasket was deformed badly with the rearward facing part blown loose. Blowback was shooting straight backwards past the cinder head.
I removed the old gasket and tried to run without it. No way. But I stopped at a hardware store and bought a roll of Teflon tape. I pulled out a small stretch of tape, folded it in half and rolled it into a string that I carefully roped around the the top of the cylinder. I clamped the head back down and it actually worked! I made it home!
It was far from perfect as I still had leakage and loss of power. I thought I would make the gasket thicker. It worked for a second and then POP! - it blew the gasket out of the back! Looked like a piece of graffiti sticking out.
I've examined the head and the top of the jug. The top looks pretty flat to my 50+ year old eye. The head itself may be a bit warped, with a high spot that would face directly rearward. I did some very light sanding to smooth out any rough spots that might make that part higher but, honestly, it's hRd to see exactly where I need to sand.
I am gonna spend $9 on a copper piece that I will cut to replace the old messed up gasket. But it will sicken me to go to that effort just to see the thing get destroyed. Are there any clues I can find that will allow me some idea if I am in a workable condition here?
Before attempting the return ride, I re torqued the head bolts (they were a bit loose) and checked the spark plug for gap. For about 3 miles, I kept working to get things running, checking every system of the bike. Electrics were good. Throttle cable was operating nicely and the jet was clean. No problems with the choke. But by this time, I had noticed blowback from the cylinder head.
Finally, I removed the head. Bam! Saw the problem: aluminum gasket was deformed badly with the rearward facing part blown loose. Blowback was shooting straight backwards past the cinder head.
I removed the old gasket and tried to run without it. No way. But I stopped at a hardware store and bought a roll of Teflon tape. I pulled out a small stretch of tape, folded it in half and rolled it into a string that I carefully roped around the the top of the cylinder. I clamped the head back down and it actually worked! I made it home!
It was far from perfect as I still had leakage and loss of power. I thought I would make the gasket thicker. It worked for a second and then POP! - it blew the gasket out of the back! Looked like a piece of graffiti sticking out.
I've examined the head and the top of the jug. The top looks pretty flat to my 50+ year old eye. The head itself may be a bit warped, with a high spot that would face directly rearward. I did some very light sanding to smooth out any rough spots that might make that part higher but, honestly, it's hRd to see exactly where I need to sand.
I am gonna spend $9 on a copper piece that I will cut to replace the old messed up gasket. But it will sicken me to go to that effort just to see the thing get destroyed. Are there any clues I can find that will allow me some idea if I am in a workable condition here?
