Johnson / Evinrude head interchangability?

[iloveketchup]

Hello,

I have what i think is a 1985 johnson 140 HP motor. The guy tells me the powerhead is a 91 or a 90 but originally was a 85.

The head stamping is 328624-4 on the port and 328624-3 on the starboard.

If one looks on ebay there are quite a few evinrude and johnson heads that appear to work for a 140 but not the same casting. Is there somewhere that shows if these parts are interchangeable with part numbers?

 

[Faztbullet]

Re: Johnson / Evinrude head interchangability?

If it a 1985 140 its a small bore looper and the 90-91 85 is a crossflow and the heads will not interchange. Have you got heads off? Are pistons semi flat or have a large ridge on them? If semi flat its a looper and heads from a 1985-87 120 or 140 are direct replacments but the later model will work, you just have to do a few hose reroutes and do away with the power boost cooling. If its a crossflow just make sure it a 3.5 inch bore head and it has the bosses on head to mount coils....

 

[iloveketchup]

Re: Johnson / Evinrude head interchangability?

I haven't had the head off yet.

I notice there are two different what may just be cosmetic designs. I have the one that looks like this:

Ebay Link

and not like this:

ebay link #2

Does that matter at all?

 

[emdsapmgr]

Re: Johnson / Evinrude head interchangability?

Follow Faztbullet's advice. The two heads you show are not for the same engine. The first listing is for a looper head-according to you, the correct style for your engine. The second posing is a head for a crossflow-it won't fit a looper.

 

[iloveketchup]

Re: Johnson / Evinrude head interchangability?

I am. I'd just like to find a way to identify the parts prior to doing the work of removing the head. Right now the engine is sealed up and on the boat.
I'd like to keep an eye out for a decent set of used heads.

The starboard also has slightly low compression too (65 psi) in one cylinder and has hit temp cutout twice. I may have clogged a water passage or who knows. It's worth opening up and checking for problems. It could be something simpler but well... it's something to toy around with this winter. The guy i bought it from did a horrible heli coil job on one of the port side cylinders and essentially made it near impossible to change the plug or check compression too. It's not really time efficient trying to fix.

 

[Faztbullet]

Re: Johnson / Evinrude head interchangability?

I got several sets of these small bore heads if you need one. 65psi is way low on that engine, should be 100psi or above. Pull head and inspect the exhaust port and walls as this engine is a bridged port design and do scuff in this area do to high heat and lack of lube thru passage in piston(carbon blockage).

 

[iloveketchup]

Re: Johnson / Evinrude head interchangability?

How much are you expecting for set or at minimum port side in today's market?