Snapped a spark plug in my ZX7R this weekend

Hi Guys,
Just thought I would share with people my experience of snapping a spark plug off in the #1 piston of my ZX7R. Up untill this Kawasaki ownership has been pretty smooth sailing. I have changed the battery after that died, it had been hard to start and smelt of fuel if it sat for a few days. I am shutting fuel tap off now to see if that helps and maybe I was using to much choke and flooding her.

But anyway thought it was time to change the oil, filter and have a look at the spark plugs. Oil and filter change went smooth, had her up on a mate's bike stand, so no complaints there. Got him to help with tank removal, so all good there too.

But when it came to changing the spark plugs things went a bit pear shaped. Pulled # 1 out fine but when it came to installing the new one I got a little clumsy. I thought the little washer had to compress more and she sanpped on me. I thought that I had pretty well killed her. Luckily the porcelin centre came out leaving some chance of getting it out without pulling down motor.

Now my mate, who I now refer to as "The Doctor", machined up a joiner so we could get down to the remains of the spark plug. Thankfully the ezi-out caught and the remains came out.
Found another plug and installed them all this time using a bit more caution and care.

So I feel pretty lucky. Riding back to my house felt pretty good and she felt a fraction more responsive too. Just thought I would ask if anyone else has had an experience like this or if there are any other things I should be more cautious with on a 16 year old Japanese motorcycle.

I just can't get past your user name in the context of this story A bit like Mr Faulty with his zx6r which had a million problems

When was the fork oil last changed out?

Yeah I know. Clumsy + Motorbikes = Fail. But I do like riding them so much. Just thought I should get used to servicing them too. The bad thing is that I was sort of warned of how careful I should be. As the night before I took off one mirror that needed the stalk repainted. Sounds simple I know, got it painted up all good. But putting it back on I snapped one of the threads. Doh! Firm not hard is what I have been told now. Must remember Japanese hands are small and delicate. Just hope I don't do a third one as I want to put a K&N air filter in her soon as well.

Good on you and keep up the good work! You'll get a feeling for the required tension the more work you do. If you're not sure you can try to get a hold of your bikes service manual and it should have a section where all of the recommended tensions are listed. That will give you an idea of the numeric relative tensions different things require.

Just remember, if you double the length of the spanner/ratchet etc(how far your hand is from the centre line of the work), you double the torque applied to the nut/bolt/screw (with the same applied force).

great to hear that your mate got the old plug out - these can be a right bitch sometimes.

Just a tip when doing them next time - spray a touch of WD40 onto the threads - not a heap, just a dribble. This will assist in the install of the new plug, it also generally allows you to tighten them up with fingers only - until they bottom out, then its only 1/8 to 1/4 turn so they 'seat' nice.

With jap threads, especially the smaller 6 and 8mm 1.00 or 1.25mm pitch - you don't need to wail on these with the spanners at all. They just need to be snugged up by hand then a very light last push, in most applications. The only 6mm and 8mm nuts or bolts that I ever do up to factory torque settings, are the engine case bolts. Not the outer engine cover fasteners, the actual nuts'n'bolts that hold the cases together. These - and all other internal engine fasteners - must be done up to factory spec in every instance.

Turn it till it strips, then half a turn back...

(-&

Your a rough nut
You've certainly picked a great breed to learn on! I think you will out grow the 7 before you break it
Bout time there was another catch up ride im thinking..

Turn it till it strips, then half a turn back...

(-&

Also known as an "Irish tension wrench" .....

Thanks Guys, appreciate the advice or mis-advice as some may have been...
Definately feel pretty lucky as I understand it does not allways go as smoothly as it did for us on the weekend.
Probably what I will do next time is just use the tools in the Kwaka tool kit (small spanners) and not a 3/4 drive ratchet as I understand now what Tim was saying above lengths of tools applying more torque.
Just thought I would post up about it as I don't have a huge amount to say on Kawasaki's yet.
And, yes Pos, been trying to get out for a Sunday morning ride, but I have had my little girl staying at my house most Sundays lately.
Has been great to have her more often but not so good for riding motorbikes on the weekends.
Cheers

Probably what I will do next time is just not use a 3/4 drive ratchet.

Phuck !
I always use a 1/4 drive ratchet & extension & an embiggening adaptor with a 3/8 drive plug socket, it makes it a bit more idiot proof which is perfect for me.

.... just use the tools in the Kwaka tool kit (small spanners) and not a 3/4 drive ratchet.....

3/4" FMD no wonder it snapped !! 3/8" is perfect for most fittings on a bike, 1/4" stuff for the small stuff. 1/2" drive for torquing down cylinder head nuts.......and 3/4" for doing up the PTO on a Massey Ferguson !!

Mr Clumsy .....for future reference get a hold of a long t-handle magnetic 16mm plug socket. It makes life easier for changing sparkplugs on a 7R .

TIPS:
#1 Get yourself a decent 1/4" and maybe a small 1/2" or a good 3/8" dr torque wrench

"With jap threads, especially the smaller 6 and 8mm 1.00 or 1.25mm pitch - you don't need to wail on these with the spanners at all. They just need to be snugged up by hand then a very light last push, in most applications. The only 6mm and 8mm nuts or bolts that I ever do up to factory torque settings, are the engine case bolts. Not the outer engine cover fasteners, the actual nuts'n'bolts that hold the cases together. These - and all other internal engine fasteners - must be done up to factory spec in every instance."

2# Spark plugs are easily installed and removed gently using approx 4" of 5/16" (8mm) fuel hose pushed onto the ceramic insulator.
3# Bike plugs (16mm and 14mm) require the use of standard deep sockets with no rubber insert like dedicated plug sockets .. this means you have to ensure you are straight onto the plug , not on the piss or you WILL break the insulator every time.

'Clumsy' you are certainly not the first and well and truly not the last to encounter such issues . Fortunately having such mates as 'the doctor' plus the necessary skill base to sort it out saves a lot of headaches.
Rule of thumb on NEW spark plugs = seat by hand then 3/4 turn (this means firm - spark plugs ignite the fuel air mixture , they do not hold the bike together !!)

It takes quite a while for some people to get the 'feel' of what is the right torque and what is not .... but having said that , I know supposedly more experienced mechanics than myself that still either leave shit too loose or snap the farker off!? so don't be too concerned
ZX7 is a pretty sturdy bike and a weapon in the twisties - enjoy

WD works but I'm a big fan of Nickel or Copper anti seize. Make removal so much easier next time the plugs are due

Well im sn RP-7 man... So there !