stripped spark plug 25 hp evinrude

dmorray

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Joined
Jul 29, 2009
Messages
17
please please help,..............what do i do,.......ive got a 1976 25 hp evinrude outboard, and ive stripped the spark plug threads on the lower cylinder,.....i dont know what to do, and i dont know how to fix it,......the motor ran like brand new until now!!!! any help will be appreciated,....i have tap die's,.... but im affraid to use them as im sure they will not be the same thread,....tolerance,,....and so on,...what do i do for this situation>??????
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: stripped spark plug 25 hp evinrude

calm down, there are several products for fixing that. helicoil is one, there are several others also. it is best to remove the head when repairing.
 

tx1961whaler

Vice Admiral
Joined
May 31, 2008
Messages
5,197
Re: stripped spark plug 25 hp evinrude

If you a not sure that you can fix it, take off the cylinder head and take it to a machine shop. They can put a heli-coil or other insert in for you. Bring a spark plug with you.
 

Britar

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Jun 27, 2009
Messages
20
Re: stripped spark plug 25 hp evinrude

Agreed, not the end of the world, just frustrating.

A machine shop can fix you up.
 

CanWoodsman

Petty Officer 3rd Class
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May 21, 2006
Messages
75
Re: stripped spark plug 25 hp evinrude

The exact same thing happened to me with my 1968, 40hp Johnson.
The above advice is dead on.
I removed the head & took it to a machine shop. They inserted a heli coil & IIRC it cost me $20-$25. Problem solved.

Rick
 

dmorray

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Joined
Jul 29, 2009
Messages
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Re: stripped spark plug 25 hp evinrude

thanks guys that helps alot, thats kinda what i was afraid of, but atleast i know for sure now that is is repairable!!!
 

dmorray

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Jul 29, 2009
Messages
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Re: stripped spark plug 25 hp evinrude

i have one more question,....i assume that when i pull the head off i'll need to replace the head gasket when re-installing, as is with most motors. any idea the part number for that gasket?
 

CanWoodsman

Petty Officer 3rd Class
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May 21, 2006
Messages
75
Re: stripped spark plug 25 hp evinrude

I had no problem reusing my gasket. It wasn't a paper gasket but more like rubber.
NAPA list the head gasket for your motor as 18-2962
 

jaymasta

Petty Officer 1st Class
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Jul 14, 2006
Messages
236
Re: stripped spark plug 25 hp evinrude

If you are going to remove the head be VERY careful with the bolts. With that old of an engine the bolts are going to be extremely hard to get out without breaking them causing many more problems and expense. I would presoak them for a night with PB or wd40 or something similar and tap around the bolts to try to get it in there, and when you go to crack them use more and as soon as they crack loose use more and tap around to try to get it in there. Good luck.
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: stripped spark plug 25 hp evinrude

Take the head off to do the thread repair in my opinion. Some folk do it with it on but you can never guarantee that you get all the shavings out.
Just my 2 cents though.
 

14ftgrumman

Chief Petty Officer
Joined
Jul 19, 2008
Messages
416
Re: stripped spark plug 25 hp evinrude

Remove head, Take to a machine shop or small engine shop. The HeliCoil will be stronger than original.
 

14ftgrumman

Chief Petty Officer
Joined
Jul 19, 2008
Messages
416
Re: stripped spark plug 25 hp evinrude

Remove head, Take to a machine shop or small engine shop. The HeliCoil will be stronger than original.

Lawn mowers and such have this happen all the time. Spark plug threas size is pretty much the same- 14mm
 

kbait

Commander
Joined
Nov 13, 2007
Messages
2,471
Re: stripped spark plug 25 hp evinrude

Call tim's outboards 218-682-2331 and ask if they have a used one. May be cheaper than heli-coiling.
 

dmorray

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Joined
Jul 29, 2009
Messages
17
Re: stripped spark plug 25 hp evinrude

hey guys, i actually got it fixed a few weeks ago thanks to all of your comments, i put the helicoils in myself, and havnt had a problem, the only thing that is bugging me now, is that it is idleing to high, the carb. has been rebuilt and i set the idle "needle" all the way in- the backed off one and a quarter turn from there, the motor still chokes out. i ended up having to set the needle out about two and a half turns to keep it from choking out on me, but its idleing too high by doing so!! could this be a timing issue with the flywheel, or something else, maybe an idle jet in the carb. clogged? im not very good with trouble shooting timing issues or messing with the magneto and things of that nature. the motor also hesitates slightly when i "gun" the throttle handle. but when i get up to speed and on plane,....its an absolute dream, she purrs like a kitten. and it was doing this before i ever messed with the heli coil issue, the compression is good, 120 psi on both cyl. for 45 min. with no pressure lost. any suggestions??
 

crxess

Chief Petty Officer
Joined
Apr 30, 2009
Messages
559
Re: stripped spark plug 25 hp evinrude

Check your cam follower and make sure the throttle is closing all the way.
Did you wire clean the tiny idle passages behind the soft plug on the Carb?
Did you install new packing on the low speed idle needle?
 
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