Triumphrat

DMc · 11-27-2006

I had a plug come loose and broke off it's electrode and in the process ding a valve. I repaired the bike and she came back stronger than ever. The valve job made such a big difference to the bikes pull.
3000 miles later I'm riding along and all of a sudden pop....popopopoppopoo. I can hear the compression cycle. I shut it down and towed it home. When I pulled off the air box the center coil was half way blown off. When I removed the remaining screw holding it on it broke in two. The plug was completely backed out of the threads and electrode gone.

I share the wrenching on the bike with a mechanic that comes to my place. When this first happened I blamed him for not seating and compressing the crush ring on the plug. The crush ring on this plug is not crushed. I can't believe he would make the same mistake twice. He's is a good mechanic and was vigulant after the first glitch. I'm thinking that the threads in the head are somehow not letting the plug go all the way into the head thereby not crushing the ring. I'll see when the head comes off.
Has anyone else had a plug back out?

soonerfan85 · 11-28-2006

Sorry to hear about your troubles. I'd be ready to cry if after finally getting my bike to run perfectly I had this happen.

I've read on either this or the T595.net board that while not at all a common problem, this has happened with a few Triumphs. The cause seems to be not using the OEM spark plug tool to tighten the plugs. Apparently some aftermarket sockets are too thick/big and don't allow you to snug up the plug sufficiently to prevent it from working its way loose. It feels tight when torquing down the plug but it's really not due to the socket coming into contact with part of the engine casing before the plug has seated properly, thus creating the feeling that the plug has been snugged up properly. Not something a non Triumph certified service tech would likely be aware of. On the bright side, at least the plug's electrode didn't break off and cause even more damage. It's obvious to me now that I'm spending way too much time reading threads on Triumphs! :wink:

Good luck with getting your ride back on the road.

[ This message was edited by: soonerfan85 on 2006-11-28 06:24 ]

DMc · 11-28-2006

Now that makes sense. I'm sure he used his own tool to tighten the plugs. Oh, It did brake off the electrode the second time :hammer: Thanks for taking the time to post your response.

DMc · 01-11-2007

Well the bike is back together now after having the plug threads "chased" and the valves reset.
I ran a test while I had the head off. We put plugs in and tightened them up. Once we thought they were tight enough we backed the plugs out to look at the crush rings. Two of the three were not crushed. ***???
After the "chase" it seemed to work fine. I guess junk was getting into the threads and gunking up the last couple of them. So they felt tight but never were.

I did a ring job while I in the engine that deep.
I got a great tip on how to pull out the cylinder sleeves.
Clean the sides of the cylinders to remove all of the oil. Put duct tape around the cylinder when the piston is all the way at the bottom of it's stroke. Crank the cam and the sleeve will come right up with the piston. Saves you from buying the "special" tool for doing this and works better anyway.
The bike is running great so far. I can't get on it yet as I'm still breaking it in.
Has anyone else been through this other than me?

mikey · 01-12-2007

good to hear you got it sorted out again.
I'm wondering shouldn't the threads get all covered up by the plug and sit flush with the inside edge?
I had a ZX7 with the same problem,the valve cover /head was really narrow and I ended up having to grind the socket down in order to fit.
Just out of curiosity how much does it roughly cost to freshen up the topend with new rings and stuff like that?
mikey

DMc · 01-12-2007

Doing the valves was about 400
Rings were 240
Gaskets were 350
Labor was about 300
I did most of the prep work and rebuild. The head was done at a shop where they reseat the valves and replace guides. I work with a mechanic that comes to my place, that makes it much cheaper.