1988 Johnson 150 Head Gasket

[KyleM]

Hey guys,

Im heading out to look at a 1988 Stratos bassboat on the weekend and Im told the motor is a 1988 Johnson 150. Not sure what model (I believe theres 3?)

Anyways, I was told it needs a head gasket.
What are some of the other problems associated with these motors? What kind of hours do you get out of one these things before the headgaskets go in them.
Im expecting theres more then meets the eye with this thing as the entire boat/motor/trailer package is 3000 bucks CDN.

I dont mind doing some work on it. I rebuild smallblock chevs often enough so Im sure Id give one of these things a try with the right manual.

Been looking for a bass boat project for quite some time so hopefully you smart fellas will have an answer or two for a learning boat fixer upper guy like myself.

Thanks!

 

[R.Johnson]

Re: 1988 Johnson 150 Head Gasket

Pull the head with the problem gasket, and take a look at the cylinder walls, this only take's a few minute's. and will answer a lot of question's.

 

[mikesea]

Re: 1988 Johnson 150 Head Gasket

Kyle,the most important thing you can do is a compression test.how did the seller determine the head gasket is blown?For a mere 20 bucks that prob could be resolved,so I would wonder why would seller be so willing to give the package away for 3000,yet be smart enough to know theres a blown head gasket. Theres a good chance that the cylinder is scored because it ate a piston. Fact isyour a mechanic, so bring along a compression gauge, when you find a low cylinder ,ask the seller to allow you to remove the cylinder head. It would take 5 minutes and a 7/16 or 1/2 inch socket. At that point check the cyl. walls and pistons.I would bet its more than just a head gasket. And if it is,you would be right to rebuild the powerhead ,as the whole thing must be torn down to fix one cyl.Rebuilding the engine would be of no contest to you. However it is more costly that a chevy.the pistons are about $115 a piece @ 6.then machine wrk ,gasket set and berings.Id say under a 1000 if you do thework,but it would be as new. You might also remove the lowest plug on the lower unit. Its a slotted screw,kinda large. Allow a few drops of fluid out. What you dont want to see is water.There could be a teaspoon amt of condensate,but that would be the max. Oil should not be milky brown,with bubbles of water.As for the electronic parts,its a coin toss. If the engine runs but weak on a low compression cyl. then the stator,coils powerpack are probably ok. If it runs also note if the tach and charging guages work if there are any. That would tell you the charging system is working. Good luck

 

[KyleM]

Re: 1988 Johnson 150 Head Gasket

Well thanks for a lot of that info guys.

The guy gave me this story....

The boat was a trade in on a new bassboat.and the dealership that owns it has no room for fixer uppers at the moment. The guy thats selling it has told me they could probably get it in writing that it will run when a new headgasket is put in.

If he has a problem with me tearing off a head then Ill tell him to kick rocks otherwise I might be interested.

It looks like an issue of not taking care of the boat.
Its all in immaculate shape. Carpet, seats, haul, motor all look like little to no use.

Some people just dont take care of motors and when they break they just trade them in.

I will go over the thing and maybe offer him 2500.
Its actually 3200 but I haggled him down to 3k just on the phone.

Thanks again guys,

I will check back in the AM to see if anyone else has some helpful hints for me.