Spark Plug Threads

[springbok]

I have a 1988 25HP Evinrude.<br />The threads in the head for the top plug are stripped, most of them came out with the plug when I removed it. I was thinking of using a heli coil, will a heli coil be fine? A little piece of thread fell inside the plug hole, is that a big deal or will it come out if I turn the motor over, or make it's way out the exhaust?<br />Any help would be appreciated...<br />Thanks

 

[DJ]

Re: Spark Plug Threads

springbok,<br /><br />I'm not too worried about the piece of aluminum thread, However, I would still try to get it out by turning the engine over with the spark plug holes facing down.<br /><br />The Helicoil should be just fine.

 

[R.Johnson]

Re: Spark Plug Threads

The head has to come off, no matter how you make the repair. There are several type's of thread repair kit's. The best are staked in, and the inner thread's are ground off flush with the inner surface of the cylinder head. The worst come out every time you remove the plug.

 

[Paul Moir]

Re: Spark Plug Threads

R. Johnson - next time you have one of those inserts that come out with the plug, try putting some hi-temp permenant 'red' loctite on the outside of the insert, and wind it back in, and torque the plug. 24hrs later, it'll never wind out again.

 

[cobra 3.0]

Re: Spark Plug Threads

There are glue/epoxy type products available at autoparts stores that are designed exactly for this purpose.

 

[Terry H]

Re: Spark Plug Threads

Paul Moir...will the spark plug come out the next day when you use the heavyduty Loctite?...just a Thought<br />

 

[Xcusme]

Re: Spark Plug Threads

101, <br />The insert should stay in the head. Since the Loctite is applied to the outside of the insert, there shouldn't be any thread locker between the plug threads and the insert itself.<br /><br />Now, if you Loctite the inside of the insert too, well that's another matter!

 

[ledgefinder]

Re: Spark Plug Threads

Hi SpringBok-<br /><br />I definitely prefer the staked-in thread inserts to Helicoils. RJ is right about many Helicoils backing out. Same price, BTW.<br /><br />You will probably be OK to put the thread insert in without removing the head. On the other hand, removing the head is real easy on a 2stroke outboard, and you'll remove any risk of leaving crap in the combustion chamber. So choice is up to you & your level of confidence. If you do remove the head, for sure use a new head gasket & torque the head down properly (or don't remove the head in the first place).

 

[Paul Moir]

Re: Spark Plug Threads

I should have mentioned, I oil the sparkplug threads - just incase. <br />But naturally, I try to keep the loctite to the outside of the insert.

 

[Terry H]

Re: Spark Plug Threads

So the inserts you talk about aren't like the "helicoils"...they're more like a bushing...just a Thought

 

[bubbakat]

Re: Spark Plug Threads

I used locktite on mine and no problem yet. I can post you a picture of the staked in insert if you want it. Just will have to go over to the shop and break out the camara.<br />I left my head on when I did mine. I just did it one or two threads at a time and put grease on the thread cutter to catch all the little filings or cherf as it is called. I think its called that

 

[Ben Konopacky]

Re: Spark Plug Threads

cobra & or paul Question on the lock tite or epoxy having some effect on the grounding to the spark plug ???

 

[bubbakat]

Re: Spark Plug Threads

I am not them, but no it dosent