Piston Liner question

[greg112]

Hi

New to the forum, but it looks like a very helpful tool. I have a 1993 70hp Force I went to replace a blown Head gasket and Im not a boat mechanic but it looks like a piston sleeve with an outer lining around it and close to where the gasket blew a piece of the outside lining is chipped off its about 1/4 " wide by 1/4-3/8" deep and a friend told me I could JB weld that missing piece then sand well. I was wondering if this would work or not I hope to replace the boat in a year or two but I dont want to give someone else a problem if I dont have too.

Thanks
Greg

 

[gotboostedvr6]

Re: Piston Liner question

jb will not "fix" the outer aluminum sleeve i would leave it alone and just debur anything that sticks up past the deck. The ductel iron sleeve that contacts the piston is where the strength is. the aluminum outter sleeve is only there to add surface area to the head gasket mating surface and prevent the sleeve from corroding.
it would take years and years of saltwater running to affect the iron sleeve in an adverse way

 

[Frank Acampora]

Re: Piston Liner question

JB weld alone will not work. But, you must have some support there. The metal sealing ring on the gasket is slightly larger than the bore and the aluminum supports part of the metal in addition to the fiber part of the head gasket. The JB weld will just fail and blow out destroying another gasket. I had a block with the same damage and the previous owner tried to repair it with JB. Did not work.

Best solution is to have a welder build it up then grind level again.

What I tried and have not tested yet was to use a dremel and grind the break square and even, with a matching notch opposite it. I then pressed in a piece of aluminum cut and filed to match the space between the two notches with a little JB weld to help hold it in place. Don't worry, if the aluminum piece is not too thick, it will not block any water flow in the block.

As I said, I have not used this block yet so I can not say for certain that this repair worked. If you decide to try it, post results on this forum. Thanks.