I think I may have overtightened the front spark plug on my P650. Now I cant get it out. It turns about 1/2 turn and won't go any more. Any suggestions would be appreciated.

 

is it spinnig in the plug hole or dus it just stop

 

That could be the result of overtightening or, if you have run it for some time since last attempting to remove the plug, carbon build up on the bottom of the plug. Another possibility is the plug came loose while running it and the threads are damaged by compression leakage. In any case addition of more force will nearly always result in stripped threads. Unfortunitly I don't have an easy answer for you, it has been my experiance the best course is to pull the head off and see what is going on. Somtimes you can save the head when you have it off and can really get to the problem. Some heads can be redrilled and a Heli-coil installed if the threads are stripped. I have also seen a couple of heads saved by retapping to a larger diameter plug but I doubt if this can be done on your engine.

Good luck, maybe someone else has a magic bullet for you.

 

It just stops. Plug is brand new. I re-jetted and put new plugs in. Tried to take it back out to read it.

 

i have seen my uncle at his machine shop spray "super component cooler" on plugs to basically freeze them and bring them right out. it is basically liquid freon in a small spray can. by freezing the plug you "shrink" it and it will usually come right out.you used to be able to buy the stuff anywhere 20 yrs ago, but now it is hard to come by. check with an older tv repair shop, ya might get lucky and be able to buy a can from them. there are also several other alternatives you might try. most spray"duster" type cans use freon or something similar , if ya turn the can upside down it will spray the liquid out and freeze anything it touches. if that doesnt work i would take the head off and have a machine shop take it out for ya.will cost ya a few bucks in gaskets and time, but it beats the risk of stripping and/or cracking the head.good luck

 

i would advise against using a "helicoil" type thread repair as it affects the heat transfer from the spark plug to the head, and could result in pre-ignition.

how much force did you use in trying to get the plug out? maybe you might just have to turn harder. maybe it's just the washer on the spark plug that's bound up.

 

That same problem happened to me except my plug broke off flush with the cylinder head ,we tried ez outs no luck finnaly we had to remove the head apply a small amount of heat the whole process took about 8 hours (removing all the front fairing,rocker cover and cam)Most peeps dont know that the plugs are only supposed to be installed with 9 lbs of torque thats all.


My advise take the quad to a experienced machine shop you do not want it to break in the block!!!

 

Last resort

have your uncle drill out the hole to a larger diameter then press in new metal and redrill & tap to stock size.....It would have to be a tight press fit becuase of the high compression.

 

Since the plug turned about "1/2" and stopped, it makes me to think the threads are seized (galled) together which is common between two dissimilar metals when there is friction. If you just try more torque to loosen it, the ceramic part of the plug might break and you could be in a deeper trouble. So, let's try easy way first if you haven't tried yet. Warm up the engine and while the head is still hot, try to loosen the plug. The heat will expand the aluminum head more than the plug, making the plug come out easier. If that doesn't work, spray a lot of silicone based spray (something similar to WD-40) that says it works on frozen bolts/nuts into the spark plug hole. After spraying a liberal amount, let it sit overnight so the chemical has a chance to soaken into the threads. Then try to loosen it next day. Another idea is to use an impact wrench to loosen, insead of slowly turning by hand. Using the impact wrench would have a less chance to break the ceramic and the vibration of the impact would help as well. Good luck.

 

Thanks for all of the replies, guys. I removed some plastic to get a better angle at the plug and it came right out without having to use too much force.

The threads were strippet towards the end of the plug. I got a new plug and she threads easily so I don't think the head is damaged. I know not to over torque the plugs but they're in such an awkward position that one time I didn't tighten enough and was able to remove the plug by hand. Just wanted to make sure that didn't happen again.

From now on I'll just remove a little plastic for easier access.