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spark plugs stuck in head

AugerCreek

Registered
Last Subscription Date
12/19/2015
I went to change the plugs on my vg4d and two of them will not come out! Are there any solutions ? I tried Kroil but no luck!
Your brother in Christ Jerry
 

Phil P

Registered
Last Subscription Date
11/24/2013
Hello

Not much you can do. Heat the head around the spark plug with a propane torch. Not to hot you don’t want to damage the aluminum.

The just take a big wrench and screw them out. If the threads come out with the plug NAPA sells a thread repair kit that inserts a stainless steel thread repair. I have used this many times and it works very well.

If you use the thread repair don’t forget to put good stiff grease in the flutes of the tap so chips don’t go in the cylinder.


If you use the thread repair don’t forget to put good stiff grease in the flutes of the tap so chips don’t go in the cylinder. Also use a pair of needle nose pliers to break the tang off the bottom of the thread repair. You don’t want that in the engine.


Phil P
 

Bill Sherlock

Subscriber
Age
75
Last Subscription Date
07/09/2019
If it were mine, I would use an adjustable impact wrench on a deep socket. Start impacting on a lower setting and increase if necessary.

Bill
 

FWurth

One Millionth Post
Last Subscription Date
07/29/2019
One method we have had success with on aluminun heads is to break out the center of the plug and heat the plug base from the center then let cool, they will usually come right out. Or you can simply remove the head and heat the center that way if your worried about the plug residue getting in the cyl. I usually just crank the engine over with the plug out to blow out the debris. F.J.W.
 

SAMccomber

Registered
If the engine will start I would try firing it up and getting it hot, then try to loosen the stuck plugs. Aluminum expands more than steel, so when the whole assembly is hot the plugs may back out. Be careful, though. If the plug breaks free but will not thread out easily you may be pulling the threads with it since hot aluminum tends to gall easily. I would try to break them loose with it hot, let everything cool, and then thread them out if you have any doubts.

Otherwise the Helicoil kit Phil mentioned may be the route you wind up taking. The Helicoil insert is made of stainless, so the plug will never stick again.

Scott
 

Bill Sherlock

Subscriber
Age
75
Last Subscription Date
07/09/2019
Scott,

Trying to remove spark plugs from an aluminum head when the head is hot is a no-no. That's when the aluminum tends to stick to the spark plug, ruining the threads in the head. Best to allow a cool down period before removing the plug(s).

I've seen this from experience and also covered in engine owner's manuals.

Bill
 

AugerCreek

Registered
Last Subscription Date
12/19/2015
Thanks guys,since they are both on the same head it won't be so bad if I have to take off the head. Thanks again!
 

Power

Registered
I have had some success running it to operating temp, shut down, dose in Kroil, tap plug with a hammer and brass drift all around. Let cool and work wrench back and forth just a tad until you feel it is free.
If does not break free, let sit overnight with Kroil, repeat.
 

J.B. Castagnos

Registered
Last Subscription Date
01/01/2006
It will probably gall the threads if you try to unscrew it. I would break the porcelain out of it, cut to the threads in several places with a jig saw, break the pieces out and re tap the hole.
 

Power

Registered
It will probably gall the threads if you try to unscrew it. I would break the porcelain out of it, cut to the threads in several places with a jig saw, break the pieces out and re tap the hole.
I once tried that with AC - shell seems to be hardened steel - blade just dulled. May be other brands are just mild steel.
 

J.B. Castagnos

Registered
Last Subscription Date
01/01/2006
You have to have a variable speed jig saw, run it slow. A Dremel tool with the carbide burr will cut it out.
 

akretowicz

Registered
I had to use an impact wrench on low setting to get the plug out of the head on my BKN. And yes, it took out most of the threads from the head. Next project is a helicoil repair. Good luck on your project. :)
 

K-Tron

Registered
I am getting a Helicoil repair kit in sometime next week. If all goes well and the process is simple enough. I should have plenty of inserts left. I may be able to helicoil yours for shipping costs. Let me know,

Chris
 

akretowicz

Registered
Sounds like a deal to me. Thanks. I really need to get it done so I can proceed to hopefully get this engine finished. We all know about procrastination, don't we?
 
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