What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

[brianteel]

What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

I got this motor for $100 and was told it needs a top end rebuild. I am sure it will need more than that but for the price i could not let it go. it is super clean.

 

[Daviet]

Re: What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

All depends what type of damage you have. What is the compression, have you pulled the head to take a look at the pistons and cylinders? Do you have play in the rods?

 

[brianteel]

Re: What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

I have not done anything yet. I am just going by what the person told was wrong. I have to build a stand for it before i can start check but by the look of what has been taken apart i think all that was done was a compression check. I was also told that no one has tried to start the motor in at least 5 years. I am going to hunt down a good shop manual for it and check each part out.

 

[Daviet]

Re: What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

It might be best to look in the "Top Secret Files" on awakening a sleeping engine. You might want to get it started and see exactly have, might not need to be overhauled.
It would be worth the money to get a factory manual, look on e-bay or google Ken Cook, he sells factory reprints. Make sure andpurchasee the manual by using your model number to get the correct manual.

 

[brianteel]

Re: What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

i am not seeing awakening a sleeping engine in that area, although i might just missing it. Definitly getting a manual. I will post some pictures of the motor tomorrow

 

[Daviet]

Re: What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

Sorry, wrong heading, try this.
http://forums.iboats.com/showthread.php?t=158086

 

[brianteel]

Re: What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

Thanks i will be building a stand for it tomorrow and start working on it

 

[brianteel]

Re: What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

I put the bolts back in the head and found it had at least 75 compression cold (cranked very slow so could not get a good test). The head gasket looks like it is bad. Before me someone unbolted the head and the gasket was loose. I pulled the head off and the cylinder walls and pistons looked in nice shape. I am going to go the cheap route first, clean up the head replace gaskets from there up then try and run it. I think that is the best way to go instead of spending a ton of money without knowing the real condition.

 

[baitmaster]

Re: What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

Years ago a guy gave me an old Evin that was bolted to a wood stand. He said it was locked up, wouldnt turn over. I took it home and found out the prop was hitting the base of the stand. The best part was he didnt want it back.

 

[brianteel]

Re: What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

this guy just did not want to mess with it. it has been in his garage for 6 years and got tired of looking at it.

 

[wilde1j]

Re: What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

The powerhead may be fine. Did you check the compression with the plugs out? It needs to crank ~ 300 rpm to get a decent test. 75 psig isn't too bad for slow cranking.

 

[brianteel]

Re: What does a Top end rebuild of a 1986 Johnson 40hp with VRO?

the bottom plug was in and maybe turned 5 times before we stopped. someone took it apart and i am unsure if it was the guy i bought it from or the tech.