Evinrude 18HP 1960 low power

[fleetwin]

Are you saying that the oil/fuel residue is getting onto the mag plate and points??

[salnaes]

Yes. (Sorry for late answer). It’s hard to start the engine, but when I succeed it runs nicely. I pulled of the flywheel. There was fuel/oil mixture on the magplate.  The upper seal on the crankshaft is brand new. So I guess the crankshaft is worn.

[fleetwin]

Perhaps…  Is there sideways slop on the upper end of the crankshaft?

These engines have a very strange upper seal/recirc system that can mess up.  There is a vacuum passage in the upper seal/bearing area that is supposed to draw off any residual fuel/oil mix that sneaks past the upper bearing and route it down to the intake manifold.

These systems are kind of tricky, and not well thought out, in my opinion.  Sorry, I have not reviewed this entire thread again, but has the crankcase been split apart in the past?  Someone may have inadvertently installed an oring around the upper bearing.  Installing the oring will block off the vacuum port and probably will result in the mag plate getting sprayed with fuel/oil residue.  There is also a vacuum port that runs down from this area into the intake manifold.  If this passage is plugged, or perhaps the wrong intake gaskets were used, the same issue will result…

[salnaes]

Thank you for helping me, fleetwin. Sideways slop on the upper end? Not likely, I doubt it. I did a total overhaul myself. The Power head was completely dismantled in 2022/23. Crankshaft, rods and pistons went out. New pistons and rings, new seals (upper and lower in crankshaft), all gaskets are new. There is no O-ring mounted on the upper crankshaft bearing . All passages are open, guaranteed. I cannot see that the intake gaskets are wrong either.

My concern is rather the condition of the upper end of the crankshaft. It had a blueish color and was a little pitted.
Take a look at this post: https://www.aomci.org/forums/topic/crankshaft-condition/

And this concern:
https://www.aomci.org/forums/topic/crankshaft-condition/#post-269944

Do you think fuel/oil it’s likely to pass between the new upper seal and the crankshaft? If so, do I have to dismantle everything again and buy a proper crankshaft in good condition? Or is there some quick fix?

 

[salnaes]

Here’s a picture showing the crankshaft upper end before assembling.

 

[salnaes]

Yes, I see there’s an o-ring on the outside of the upper bearing lying on the bench. But after some talk about this here on aomci I removed it before assembling the crankcase. There’s a topic on this matter:

https://www.aomci.org/forums/topic/seal-upper-crankshaft-bearing-evinrude-18-hp-1960/

I’m more worried about the pitted area on the crankshaft.

[salnaes]

Update. Due to hard winter conditions my struggles with the 18 HP has stopped. I have to wait for spring to come with warmer weather.  Happy New Year to you all and thanks for all good advices.

[Buccaneer]

Would it be possible to replace the needle bearing with a bronze bushing?
The pits in the crankshaft might be less damaging.
Of course, after all the time and money you put into it, a better crankshaft
might be best.

Prepare to be boarded!

[salnaes]

I’m not aware of any bronze bushing that may replace the upper needle bearing. Do you have a part number?

[Buccaneer]

salnaes wrote:

I’m not aware of any bronze bushing that may replace the upper needle bearing. Do you have a part number?

Maybe a last resort thing to do, or a “poor man’s” fix,
but it would have to be custom made.

 

Prepare to be boarded!

[Author]

Posts