Stripped spark plug
- Thread starter Rambeezi
- Start date
Spark plug won't come out but will turn evenly in either direction. I'm guessing I'll need to take it to shop at this point or is can I fix this myself? Are we talking major repair here?
Seesm
All love no fight....
I would get the motor out of the chassis and maybe take the head off apply pressure (from the dome side) while spinning with your plug wrench couner clockwise... Your gonna have to helicoil it for sure... You will want to do that off the bike or sure... Have to drill and tap larger and pop a heli-coil in and that will make a mess before you clean it up...
ST Guy
Well-known member
Yes. Major repair. You must take the head off to properly repair it. Bummer.
In the future, remember that spark plugs don't need to be cranked on. Just enough to snug them up and compress the crush washer a bit. Then, after the bike has been run for awhile, go back in and snug them up again. And don't forget to use some anti-sieze on the threads. But keep if off the insualtor.
In the future, remember that spark plugs don't need to be cranked on. Just enough to snug them up and compress the crush washer a bit. Then, after the bike has been run for awhile, go back in and snug them up again. And don't forget to use some anti-sieze on the threads. But keep if off the insualtor.
Grease_Monkey
Sloshie Joshie
you do not need to take the head off. put a thread-cert. in it, and if it pops out again, then take the head off. you have nothing to lose to try that first.
ST Guy
Well-known member
Yes, you do have something to lose. In order to do any kind of repair work on that thread, you need to drill out the old threads, tap new ones for the insert and then screw in the insert. The drilling and tapping operations generate plenty of metal fragments and even one of those in the combustion chamber can fuck things up when you restart. And there's no way to tell for sure if you've gotten all the metal chips out. Plus, if you screw the threadsert in too far or not far enough, you end up with sharp exposed edges in the combustion chamber. That can lead to pinging and predetonation. Yes, it can be done. But I'd only do that on an engine you really don't give a shit about.
Another note: If you overtightened one plug, you likely overtightened the others as well and it's likely there is damage to the other threads even though you don't know it yet. While the head is off the engine, I'd just have all four plug threads repaired regardless of whether or not they actually show damage. And properly done, the threadsert will be installed so it extends into the combustion chamber a bit (making sure it's properly positioned on the plug side) and then the excess will be carfully ground off to match the existing shape of the combustion chamber. Like I said, if you give a shit about the motor, you'll have the head pulled and then have an expert who really knows how to work on heads to the actual repair work. These may be two different people. One to pull and install the head. Another to actually do the repair work.
And don't let some mechanic just use a hand drill and drill out the old threads. The work must be done on a mill and the head must be set up properly at the correct angle. Don't cut corners.
hapamoto
四世
yea just drill it out and use a vacuum to suck up as much shavings as possible then blow out the cylinder with air and you could even try and get a small tube adapted to a good vacuum and work your way down inside the cylinder to be sure you got as much of the crap as possible. Then put in your insert and away you go. Most small shavings will get blown out the exhuast at start up.
My .02 we done it on cars alot!
good luck and keep us posted.
My .02 we done it on cars alot!
good luck and keep us posted.
ST Guy
Well-known member
Whatever.
Like I said, if you don't give a shit about the motor, then do it the cheap, quick, and dirty way. And be honest when you finally sell the bike and let the buyer know how the repair was done and see what happens to the resale value. (If the buyer knows what their talking about.)
Like I said, if you don't give a shit about the motor, then do it the cheap, quick, and dirty way. And be honest when you finally sell the bike and let the buyer know how the repair was done and see what happens to the resale value. (If the buyer knows what their talking about.)
Grease_Monkey
Sloshie Joshie
I've done plenty of spark plug thread repair, air cooled VW, and ford 4.6 modular V8 are some of the most common. greasing the drill and tap will reduce the amount of shavings that fall into the motor. using a vacuum, compressed air and a fiber optic scope can tell you if you got 99% of the shavings out. Plus the aluminum is much softer that the hardend seats and valves of these motors, and minute particles left behind will pass without harming engine componants. would i do a helicoil on an F1 race car, or a top fuel dragster, no. But with a little skill and the right tools it can be done properly without incident.
Seesm
All love no fight....
I have a machine shop and I can tell you st guy is really right on... If you do not give a hoot about the motor quick and dirty is ok but truly you can not get all the shit out... Do one cylinder and pull the head off and see what you missed after sucking it out and stuff... If you were doing a race lile paris to dakar ok maybe but fix it right and have the piece of mind to know you did it "right" getting 99% of the aluminum out is ok but 100% is the "right" way... Btw you can do it on a really nice drill press you do not need to do it on a mill but that is best as well... ST guy right on!!
paladinnorcal
Well-known member
Helicoil on a head that is on the engine is a BAD idea. Ask any professional mechanic and he is going to say pull the head. Metal bits in any engine are not a good idea, in a motorcycle engine it is a really bad idea. The shade tree mechanic group may have other opinions but if you want you engine to last have it done the right way.
augustiron
2fast 2live 2young 2die
whatever repair you do, don't use a Helicoil, use this
http://www.timesert.com/html/bigsert.html
the problem with doing it while the head is on is that any chips you don't get may get slammed between the valve and seat as they exit and get trapped there and you will lose the seal, they aren't likely to damage the rings or the cylinder.
http://www.timesert.com/html/bigsert.html
the problem with doing it while the head is on is that any chips you don't get may get slammed between the valve and seat as they exit and get trapped there and you will lose the seal, they aren't likely to damage the rings or the cylinder.
hapamoto
四世
do what you feel is right and you can only blame yourself. but it really is up to what you want to spend! Yes you can do it better or lets say more correct by pulling the motor apart and putting it on a mill or drill press and getting the hole drilled out exactly the way it came from the factory. but truthfully if you drill it at a slight angle it aint going to make a bit of difference. Like the other guy mentioned you are talking about aluminum and it is much softer then your cylinder wall or valve/seat.
Best bet buy a new head.
second take it off and redrill and helicoil it
third drill it and helicoil it (do a real good cleaning job rev the shit out it to clear the particles) and see what happens.
eitherway you are F ed cause you have to deal with this.
get some balls and do it yourself and see what happens you will learn that way. trust me.
Best bet buy a new head.
second take it off and redrill and helicoil it
third drill it and helicoil it (do a real good cleaning job rev the shit out it to clear the particles) and see what happens.
eitherway you are F ed cause you have to deal with this.
get some balls and do it yourself and see what happens you will learn that way. trust me.
hapamoto
四世
yes this is a good idea it is a more solid substrate for the plug. They have different helicoils for plugs vs other applications.
Grease_Monkey
Sloshie Joshie
i am a professional mechanic. I have no problems with repairing stripped spark plug threads. The engine will last if the thread repair is done properly and professionally. Aluminum is softer that anything in the engine. it does not hurt anything.
Grease_Monkey
Sloshie Joshie
I don't using a "helicoil" for spark plugs. a timer sert, or thread sert, how ever you state it is the only way to repair spark plugs