Forum

[Midge]

I can't get it to seat even with grinding. There's still torch light showing. I even bought a new valve and ground that but still the same. It has never had great compression and I think now it is why the previous owner sold it. It starts and runs ok, but when you turn it over you can plainly hear air passing towards the carb on compression. The valve seat looks fine and isn't tilted or anything, do you think I should get the valve seat recut? only I am very short of cash being out of work for a year now and no income, If it is going to cost a lot I may have to get rid and use the pedal cycle. I found this after replacing the beheaded piston which cost a fair bit to put right although I think the valve problem was there before. I also noticed that the alloy con-rod had been pitted quite badly by the failed piston and really should have been replaced, again, cost intervened. I have thought about going diesel, but no money. 2000 500 Bullet

[Alan R]

Hello MIDGE,---------OH dear !!! Even with a new valve the problem is still there ?? I wonder if the failed crown has damaged / dislodged the cast-iron guide ?? I know you don't want to hear this BUT--- after any major event where so much kinetic energy can be transferred in an instant you really must do a complete and thorough strip of the head and all associated items----even the push rods can become buckled if the detached piston crown touches a valve, if only just for an instant.... OK, so that's worst case scenario---- let's work within the parameters that you have ?? Dismantle the valves, springs etc and give the guides a thorough clean & visual inspection, looking for any cracks or bits missing off the nose... I personally would have both changed for new ( Bronze )anyway..... Place a long bar of same diameter into the guide and see if it looks off-set or off-square.... Similarly with the seats----check for loose or damage. Again, personally I would have them changed at the same time as the guides..... at least that way we know all is back to "as designed" status. Where are you in the country ? I'm near a very helpful cyl head shop.(Motor cycle friendly also !!)) Might be able to keep those cost down a tad.

[simon]

Getting the seat re-cut would be the cheapest option. If you can see daylight its clearly either out of true or off centre and so a cut will be required either that or a new seat (no so cheap) but even if it leaves the seat a bit low at least you'll get some use out of it.