Logo
FULL SITE MENU

1971 9.5hp Evinrude with lean idle

Re: !971 9.5 Evinrude with lean idle

Here are the pics. They're linked because I can't upload attachments for some reason, and I would rather not have the full size pics messing everything up.

This is the cylinder head. Nothing out of the ordinary here.

http://i312.photobucket.com/albums/ll331/thx997303/Boat/100_2320.jpg

Here is the top cylinder.

http://i312.photobucket.com/albums/ll331/thx997303/Boat/100_2325.jpg

Here is the bottom cylinder.

http://i312.photobucket.com/albums/ll331/thx997303/Boat/100_2326.jpg

And here is some random plug in the outer exhaust cover. Not sure what it does, but I can easily slide it in and out with my fingers.

http://i312.photobucket.com/albums/ll331/thx997303/Boat/100_2327.jpg

Nothing really appears out of the ordinary.

Needs a decarb, and a new head gasket for sure, but it seems my cooling issue is not caused by the head gasket.

Time to get the powerhead gasket set and start inspecting some things.
 
Re: !971 9.5 Evinrude with lean idle

How much of the crumbly head gasket was intact when removed? I have'nt seen anything like that. Maybe a head gasket thats squashed, or burned through an 1/8 slot, but usually it's a hundred percent there. Chunks of that could easily clog up the works. Could be normal, I guess.
 
Re: !971 9.5 Evinrude with lean idle

Thing is, I can't see anything clogging up the works.

Of course I will have to pull the exhaust cover to really know.
 
Re: !971 9.5 Evinrude with lean idle

Tore the motor down to a block holding the internals. The exception being the armature plate is still one.

Didn't seem to be any blockage. Small amount of sludge at the bottom of the inner exhaust cover.

There is some black greasy substance underneath the armature plate.

I wonder if maybe the upper crank seal is leaking on my motor as well.

Also, it appears that the gasket for the little cover on the intake manifold at the bottom of the engine, appears like it was leaking.
 
Re: !971 9.5 Evinrude with lean idle

The oily sticky stuff under the mag plate is most likely coming out of the upper seal. Blow out the water passages with compressed air to see if anything comes out.
 
Re: !971 9.5 Evinrude with lean idle

If you have compression and spark, I'm still finding fault with the carburetor.
 
Re: !971 9.5 Evinrude with lean idle

Compression was low but even Joe.

What I can't understand, is after going through the carb, and adjusting it according to your instructions, why is it still giving me issues?

Anywho, the previous owner had torn it apart like I have, only when he put it back together, he reused the gaskets.

So, to eliminate the unknowns, I'm replacing the gaskets.
 
Re: !971 9.5 Evinrude with lean idle

Well, new powerhead gaskets and a new upper crank seal and the 9.5 runs great.

I also replaced the impeller. Just figured it was a good idea.
 
Re: !971 9.5 Evinrude with lean idle

Finally got new upper crank seal in place. Old one was punky from alcohol fuel. Motor runs like brand new, idling at 500 rpm. Wow! Happy now.
 
Re: !971 9.5 Evinrude with lean idle

You can get the old crank seal out by drilling some small holes into the seal and starting a small screw just the right size into the holes, then using the screw heads, pry up with a small bar or screwdriver until the seal pops out. BE CAREFUL not to scratch the crankshaft surface and vacuum out any debris.
This is my trick as the seal is located down below the crankcase flange and very tight quarters to work in.
 
Back
Top