spark plug help

[gavhowe]

I have had my Falco for over a year now bought second hand and it has never missed a beat till now.

The bike would ride fine when you were on the throttle, but when you rolled off and let the revs drop to low RPM and accelerated again there would be a pop a small delay and then it would go.

My thoughts where plugs and leads, checked it all out and found one of the front plugs (upper one) had worked itself loose.

So i started to unscrew it to have a look at it and could only turn it 2 turns before it binds up and wont unscrew any more. So I screwed it back in and it went in a long way before it seated and went tight.

The bike now seems to run great again, but on 1 or 2 times it still some times has this little pop.

The spark plugs are Iridium tipped NGK so should not need to be replaced for a long time. My thoughts are that the plug may have got heavily sooted up when loose and this is why is does not always fire correctly (hense the pop). This may burn off over time.

Why do you think the plug will not come out, as I would have thought that if the threads where damaged it would not screw in or out. I dont wont to force the plug out as this could break something or drop something on to the piston.


Thanks

Gav

[Falco9]

Bit worrying eh??? Have you used an airline (high pressure if you can) and blown out the plug hole recess before trying to remove the plug?

Because the plughole is so deep the front plug does get an awful lot of crap in there (especially if you ride all year round), it could just be a lump of muck or even a small stone binding the plug and stopping it coming out.

I can't think of any other reason at all why it shouldn't unscrew, especially as you say it's tightened down OK and the bikes running fine.

Its very difficult (some would say impossible) to "soot" up an iridium plug, as soon as the bike fires the plug will be clean (the tips are tiny)

I'd be tempted to make 100% certain the plug recess is clean and try to remove it again

F9