Spark Plug popped out

[indianboy7]

Hello all...

I was riding my '05 600 the other day and it started missing pretty bad with a lot of vibration. I pulled over to take a peek and saw one of the spark plugs laying on the exhaust manifold. I'm going to tear into it tomorrow to see the damage, but I have one question: If there is no damage and the plug just backed out due to vibration, would putting some blue threadlocker on the sparkplug be a good idea to prevent this from happening again?

Thanks in advance

[kevin2502000]

No thread lock will cause problems later on, just torque properly.

[akarob]

The ceramic in the plug is fragile. So is the end, one tap and the gap will change. Make sure you at least check the gap.

Make sure you clean the threads well and don't use anything on them. The only thing I've ever put on spark plug threads is a little bit of anti-seize.

[GregS]

Quite often the plug will blow out with some / most / all the threads from the head. You may need to do what I had to do, repair the 10mm threads with an insert or bore out the head to accept 12mm plugs.

[hardlydangerous]

you can repair the threads using a Timesert.
Some have used helicoils but a timesert is much better.

I have done it many times on the engine but be sure to grease the tap well and blow out any chips after cutting the seat BEFORE you remove the tap.


If the threads are damaged and I would be money they are, do not try to install the plug again, you could strip it completely and then you have a bigger problem stating the tap or you could even break the spark plug off.

[indianboy7]

Thanks for the info everyone...I'll be taking a look tomorrow. If the head looks damaged and can't be repaired with a heli-coil, etc. etc. etc., where's the best place to get a new head?

[hardlydangerous]

The head can always be repaired far cheaper then a new head

[indianboy7]

Well finally got in there....the threads for the spark plug that popped out were just fine...turns out the PO had the same thing happen on another cylinder and they overtorqued that plug. The threads for that one were stripped when I pulled the plug out. Off to the shop she goes....hopefully they can do it without having to take the engine out. Thanks again to everyone for your advice...

[mammut89]

you need to tighten it with 30nm if you want it 100% correct

[indianboy7]

in case anyone's curious...just got the bike back...2 time serts and a whole lotta cash later, she's running perfect. Never heard of a time sert though....any opinions?

[hardlydangerous]

did you not read my first post?

they are the best way to repair a stripped spark plug hole andthe only thing i'll use