Spark plug weirdness

[MARKC]

Have had my 04 Tiger since November 06.It was last serviced in June 05 at which time it had 5729 miles on the clock. I took it in for its 12000 mile service yesterday (11200 on the clock).  The mechanic told me that two of the plugs were missing electrodes. His opinion was they had snapped or sheared off and not melted. The bike runs perfectly.It starts quickly even from cold.Acceleration is very good (better than my 900 as I expected) and power delivery is smooth and consistant throughout the rev range. Fuel usage was 190-210 to reserve. Tick over was smooth and steady.There was no noise,smoking exhaust or oil usage. In fact no indications that anything was amiss. I dont thrash the bike and I know the previous owner did not either. The mechanic states the bike is A1 apart from his discovery.



A duff batch of plugs.? Heavy handed plug gapping at some point.? Some sort of spark erosion process.?



Anybody had any similiar experiences.?

[iansoady]

Definitely sounds weird to me. Is the mechanic saying the side electrodes are missing? If so, that would make the plug gap about 5mm and I can't see how it would run like that. If it were the centre electrodes even more so.



I (as have others here) have suffered with incompetent and dishonest Triumph dealer mechanics. Are you sure you trust this one?

[MARKC]

I suppose if I had said there was a problem with starting or rough running he might have come up with a bullshit story or tried to con me into some expensive engine surgery. But it was running well when it went in and he was at a loss. I have just heard from a guy on another forum that exactly the same thing happend to him last year on the centre pot on a speed triple. He does his own spanner work and could find no reason.

[Guest]

Could be that they are Irridium plugs which have a very small centre electrode and the mechanic needs glasses.    :roll:

[MARKC]

I dont know the difference between iridium and common garden variety plugs. The worn one he showed me had nothing projecting from the rim of the plug that could be sparked off. I'll have to find a picture of an iridium to check it out

[Guest]

So it's the bit from the rim that's gone. That IS weird. Irridium has a small CENTRAL electrode but the tab from the rim is roughly the same as the cooking models. I dunno then. It's wonder that it still ran OK.

[birdman]

Well you're not alone , just pulled the plugs from my 2000 Girly and much to my supprise # 1 plug was missing the the ground electrode , took a good look under a jewelers loop and it has been running that way for a while . It idled a little rough but ran just fine .I guess it spit the piece out .