Johnwhit
Registered user
cheers dude, head gasket, valve & a few odds & ends delivered today for the weekend !
help no compression !
- Thread starter Johnwhit
- Start date
DaveGSCymro
Registered user
- Joined
- Feb 21, 2005
- Messages
- 1,504
- Reaction score
- 0
Valves often burn out because of a tight tappet or something holding the valve open slightly. On the exhaust stroke the gas is pushed out and will find the first available point of exit, this is whee you have a missing part of the valve, more likely to have burnt away than dropped into the cylinder, although it would be worth checking the bore.
Let us know how you get on.
Let us know how you get on.
I'd only be replacing the burnt valve but check the other one is seating OK and maybe clean up the stem and lap in with some fine paste.
As previous posts, the cause will probably have been that the valve was leaking slightly, either due to wear on the valve or seat, or possibly tight valve clearances, so limited value in replacing a valve that is not damaged.
As previous posts, the cause will probably have been that the valve was leaking slightly, either due to wear on the valve or seat, or possibly tight valve clearances, so limited value in replacing a valve that is not damaged.
Johnwhit
Registered user
an update on my tale of a broken valve.
I replaced the failed valve & lapped it in and it looks good.
the other valve had a bit of dammage on the sealing bit but I managed to lap it so it looks good. -its not as good as I would have liked but its a million times better than it was.
Went out today & put about 2 hours riding in and all seems well.
the only slight worry is the bike still pinks badly if I open it up fast in top at about 70 without changing down. - if I only give it 3/4 or less it doesnt pink at all.
I also removed the yellow cat code plug to help it run a bit richer - dono if that will help ????
any way thanks to all for the help, Stepptoes guide made it seem like I had done it before and helped a lot
cheers & thanks
John
I replaced the failed valve & lapped it in and it looks good.
the other valve had a bit of dammage on the sealing bit but I managed to lap it so it looks good. -its not as good as I would have liked but its a million times better than it was.
Went out today & put about 2 hours riding in and all seems well.
the only slight worry is the bike still pinks badly if I open it up fast in top at about 70 without changing down. - if I only give it 3/4 or less it doesnt pink at all.
I also removed the yellow cat code plug to help it run a bit richer - dono if that will help ????
any way thanks to all for the help, Stepptoes guide made it seem like I had done it before and helped a lot
cheers & thanks
John
Well if it leaks air lets hope that valve doesn't get a hot spot and burn, the same as the other valve.
Matt Padgham
Registered user
It was the exhaust valve after all, right hand side. Didn't realise quite how expensive the exhaust valves were! Not going to end up being that cheap a job
As ever, thanks for all the advice.
As ever, thanks for all the advice.
Johnwhit
Registered user
Matt,
sorry to hear you got the same exhaust valve problem,
its not as hard a job to do as I thought , but if you pull the head yourself (as per Steptoes guide) you can get the valves & if you can afford it get a shop to do the face & put the new valve back in, it shouldnt cost you to much. it was the money made me only replace the one when the other wasnt in the best shape but it lapped in ok (i hope) - i think it maycome back to haunt me one day but I will hopefully have enough one that day to take off both heads and replace all the valves & guides at a shop to bring both heads up to new.
I wonder if me putting back the yellow cat code plug that was disconnected when Igot the bike caused it to run lean & burnt the valves ?? -no idea,
anyway its been a week and its still running
i suggest pull the head yourself and take it to a motor shop with the new valves.
A guy in Worcerster quoted me £40 to cut and install valves into my head -only found this out yesterday LOL!
sorry to hear you got the same exhaust valve problem,
its not as hard a job to do as I thought , but if you pull the head yourself (as per Steptoes guide) you can get the valves & if you can afford it get a shop to do the face & put the new valve back in, it shouldnt cost you to much. it was the money made me only replace the one when the other wasnt in the best shape but it lapped in ok (i hope) - i think it maycome back to haunt me one day but I will hopefully have enough one that day to take off both heads and replace all the valves & guides at a shop to bring both heads up to new.
I wonder if me putting back the yellow cat code plug that was disconnected when Igot the bike caused it to run lean & burnt the valves ?? -no idea,
anyway its been a week and its still running
i suggest pull the head yourself and take it to a motor shop with the new valves.
A guy in Worcerster quoted me £40 to cut and install valves into my head -only found this out yesterday LOL!
Similar threads
