86 johnson 28spl head gasket question

[cm20]

long story short got this motor off craigslist that needed a water pump for 200 bucks 1986 johnson 28spl....j28elcdc...

guy swore he caught it as soon as the indicator stream stopped, so i bought a cheapo water pump kit off ebay

(lesson learned the oem was 15 bucks more) installed water pump, motor ran great strong stream from the indicator...

3rd time out motor revved high about 1/2 mile from the launch and smoked alittle more than usual so shut it down and

trolled back with the electric...started motor at home head gaskets blown checked out lower unit turns out my new p.o.s

water pump kit disintegrated in the housing. pulled the head off cylinders look good exept for one small score mark about

1/2 inch long on top cylinder......do i replace the head gasket and see how it goes or go full rebuild and bore the block

new pistons etc. etc. or forget about it because i bought it for a parts motor for the same one i already have that

runs great...sorry about the spacing trying to double space so its easier to read but a few words get left behind

it was intended for an 18 foot starcraft ive been messing with (whole thing will empty besides 1 side console and

dimond plate alum. floor think the old 30hp johnnyrude will push it ok?

 

[jasper60103]

Re: 86 johnson 28spl head gasket question

Sorry to hear about your misfortune.
Changing the head gasket is probably worth a shot, but I'm still concerned about the cooling issue. Any ideas why the water pump failed? I would address that problem first. Good luck.

 

[tosoutherncars]

Re: 86 johnson 28spl head gasket question

I agree with Jasper; I don't care how cheap the impeller was, it's unlikely to disintegrate that soon unless there's another problem (i.e. excessive wear on the wear plate, lack of lubrication, a missing o-ring or a blockage somewhere).

What's your Starcraft rated for, 50-75 HP? (Should be on a plate near the transom somewhere.) I think the general rule is that you should have at least 70% of max capacity; a strong 28 or 30 should get a lightly loaded boat up on plane OK, but you know what they say, there's no replacement for displacement!

-Duncan

 

[cm20]

Re: 86 johnson 28spl head gasket question

thats what i was thinking something else had to happen for the impeller to just fall apart like that...ive replaced them before and they were fine. ordered a new head gasket and impeller kit(omc) so well see how that goes after i put the head back on and do a compression test. i figure a 25 dollar gasket it worth a shot before a complete tear down.

think it would hurt anything to dump alittle sea foam down into the cylinders while the heads off?? and im trying to figure out how to get the old seal out of exhaust housing the the water tube goes into way up in there if anybody has any tips for that it would be appreciated, i read somewhere that a 12ga cleaning brush on a drill works but havent tried it yet

 

[Faztbullet]

Re: 86 johnson 28spl head gasket question

What brand was the impeller ???? The reason I asked as if its a Sierra brand and it a defect they will replace it and pay for damages to your engine...

 

[cm20]

Re: 86 johnson 28spl head gasket question

im not sure of the brand, cant find the reciept looks like im s.o.l on that idea thank you though for future reference......i think the boat may be alittle happier now picked up a 1975 tower of power mercury 150 off clist today for 75 bucks!