Cylinder head repair

dakotahoku

Seaman Apprentice
Joined
Dec 10, 2007
Messages
32
35hp 1995 johnson, What would be the best way to repair a damaged spark plug hole?
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Cylinder head repair

best is to remove the head and helicoil it, second is to use the correct lenth and thread size insert and repir it in place.
 

dakotahoku

Seaman Apprentice
Joined
Dec 10, 2007
Messages
32
Re: Cylinder head repair

Thanks for the quik reply! I was thinking of buying the helicoil kit from NAPA ($40.00) and doing myself. The only problem is removing and putting the cylinder back together. I know I need to get at least the head gasket. Is there anything special that I have to do to when I put the cylinder head back together?
 

Harker

Chief Petty Officer
Joined
Sep 21, 2003
Messages
452
Re: Cylinder head repair

You have to torque the bolts in sequence. Instead of a Helicoil, you could probably buy a good used head on ebay or a boat motor recycler for less than the kit. While you have the head off you should probably replace the thermostat and check the diverter tubes.And yes, you will need a gasket.
 

Scaaty

Vice Admiral
Joined
May 31, 2004
Messages
5,180
Re: Cylinder head repair

Check with a boat shop first...they Helicoil all the time, and don't charge much..(last I looked anyway)
 

dakotahoku

Seaman Apprentice
Joined
Dec 10, 2007
Messages
32
Re: Cylinder head repair

If found a early 80's head on ebay. Does anyone know if it will fit my 95'. It looks the same!
 

Lakester

Chief Petty Officer
Joined
Nov 17, 2007
Messages
428
Re: Cylinder head repair

Thanks for the quik reply! I was thinking of buying the helicoil kit from NAPA ($40.00) and doing myself. The only problem is removing and putting the cylinder back together. I know I need to get at least the head gasket. Is there anything special that I have to do to when I put the cylinder head back together?

hello,

have u ever drilled a big hole like a spark plug hole freehand. not too ez!! i would only use a mill. not even a drill press. a mill. i know, i have done many helicoils, in fact i did one last weekend. nothing i could do would get that 1/4 x 20 water plate bolt to come loose.

so i had a 3/8ths snub at the head once the water plate removed. carefull as i was... no deal. snub broke with ez-out. so i drilled then to 1/4x20 tap, but some of bolt still in there. too hard. only a mess resulted. grrr! so had to pop the head and chuck it up into my mill... oh my gosh... a 3/16th carbide bit was sitting already there in the R8 collet. what luck.

had snapped clean in two. :mad: it would have taken acetylene to do it, i suppose. but i was out in the country... happen to have a mill there... but no helicoil so i made my own out of 3/8ths bolt end. turned out great, even though i only had a bottoming tap. :eek: here, ck it out... :D

new 1/4x20 is just to right of right hand plug hole... shiny new ss bolthead. goes in perfectly with two fingers... smooth as can be, just like all the rest. and it IS on-center. :)

u prob can do it in a good drill press, but a mill does it ever, so much better. [subject to operator skill, of course]

also some tips: http://www.xs11.com/tips/repair/repair27.shtml

good luck and regards. hope u show us the final product.

lakester :cool:
 

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Harker

Chief Petty Officer
Joined
Sep 21, 2003
Messages
452
Re: Cylinder head repair

Seems like there is an 89 on there that is being parted out. Look on BRP's site an compare part numbers. Look in the 25 and 30 hp parts too, they are more than likely the same.
 
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