1957 18hp Evinrude crankcase leak

[BSDenning]

Hello,

I've got a 1957 Evinrude Fastwin 18hp. I purchased the motor a few months ago after it had sat for 20 years or so. I rebuilt the carb and replaced the impeller. The motor has been running great ever since. Now the motor has suddenly stopped running good. It only gets about half power and it does not idle well. It spits and sputters and will not idle down without dieing. I thought the problem could be in the magnito, so I took the whole magnito plate off and replaced it with one from a different motor, but it ran exactly the same. It has good compression, 100psi in each cylinder. So, the only thing I can figure is that the problem is coming from a leak in the crankcase. You can see little bubbles of fuel leaking out from where the crankcase seals to the block. So, how do I reseal the crankcase? There is no gasket there. It is just metal on metal. Do I use some type of sealant? Or, should I just take it apart, sand it, and bolt it back together? Thanks.

 

[jbjennings]

Re: 1957 18hp Evinrude crankcase leak

BSD,
I doubt the crankcase bubbles are big problem. Myself, I still think you have a spark problem. Have you checked it with a spark tester? Almost positively you have another problem than crankcase leaks. There is no gasket there but if you split the case there is a sealer that you can use. I'll bet F-R can tell you but I can't remember.
Good luck,
JBJ

 

[BSDenning]

Re: 1957 18hp Evinrude crankcase leak

Thanks JBJ! Before I split that crankcase, I'm going to take another look at the ignition system. It does show spark on the spark tester. But, I've got new points, condensors, coils, and plug wires that I will install before I open the crankcase. Hopefully, I will get that done today.

 

[BSDenning]

Re: 1957 18hp Evinrude crankcase leak

I replaced the coils, points, condensors, spark plugs, and spark plug wires today. I cranked it up and it ran for a second, but then it died and I couldn't get it to crank again. I took the flywheel back off and found that I had sheared the flywheel key. Luckily, I had an extra key that was on a 1956 Johnson 10hp. I put the new key in and cranked the motor up. It ran pretty good. It didn't idle very well, but it ran pretty good at high speed. I decided to take it out on the water to see if I could set the high and low speed needles. Before I left, I decided crank it one last time to make sure it would crank. I gave it one pull and it sheared the flywheel key again. I don't have another one, so I'm going to have to order one. Does anyone know where I can find some flywheel keys? Also, why is my motor sheering keys? I didn't use a torq wrench, but I thought I tightened it down pretty good. Any ideas?

 

[F_R]

Re: 1957 18hp Evinrude crankcase leak

By your own admission, you didn't use a torque wrench. That is almost a guaranteed way of breaking keys and destroying the flywheel and crankshaft. Every time you shear a key, it damages the shaft and flywheel a bit more. Eventually, it will never hold a key again.

So, from square one: The shaft and flywheel tapers must be shiny clean and dry. And not battered. You MUST use a torque wrench to tighten the nut to 40-45 foot pounds.

Those few bubbles you see may make a mess, but they are not the cause of your poor running.

The crankcase is sealed with Scotchgrip #847. Do not attempt to do any resurfacing of the crankcase surfaces other than minor dings. Do not remove any metal.

 

[jbjennings]

Re: 1957 18hp Evinrude crankcase leak

BSD,
I'm thinking that you either overtightened it and changed the flywheel taper, or undertightened it. YOu can find flywheel keys at laingsoutboards I would think, or even a BRP dealer. If not there and you don't mind waiting on mail, I could probably send you one in the mail.
My worry is that it will keep shearing them. I've also got an extra flywheel if you need it. You didn't grease the crank taper, did you? I hear that it will cause overtorqueing. It needs 45 ft.-lbs.
The only problem is that I'll be super busy for the next few days----vacation is at an end today and softball season (I'm the "coach") begins as well. It still isn't a big deal and I believe I already have one laying around, so pm me if you need it.
BTW, with a fan blowing air on the front of the motor, I have absolutely no problem setting the slow idle on my 18's in a barrel. You should be able to do the same. Use that torque wrench!!
Later,
JBJ

 

[tx1961whaler]

Re: 1957 18hp Evinrude crankcase leak

I replaced the coils, points, condensors, spark plugs, and spark plug wires today. I cranked it up and it ran for a second, but then it died and I couldn't get it to crank again. I took the flywheel back off and found that I had sheared the flywheel key. Luckily, I had an extra key that was on a 1956 Johnson 10hp. I put the new key in and cranked the motor up. It ran pretty good. It didn't idle very well, but it ran pretty good at high speed. I decided to take it out on the water to see if I could set the high and low speed needles. Before I left, I decided crank it one last time to make sure it would crank. I gave it one pull and it sheared the flywheel key again. I don't have another one, so I'm going to have to order one. Does anyone know where I can find some flywheel keys? Also, why is my motor sheering keys? I didn't use a torq wrench, but I thought I tightened it down pretty good. Any ideas?

A torque wrench is important. Too little and the key will shear. Too much and the flywheel bore will spread and the key will shear.
Non-factory (e.g. Home Depot) keys will also shear because they may not fit quite right.

 

[samo_ott]

Re: 1957 18hp Evinrude crankcase leak

First of all, I agree with Jason, I doubt the crankcase leak is your problem. Its probably ignition or fuel. But it sounds like you replaced all the ignition and that helped.

As for the key. It's critical to torque it down correctly as you have seen. That's the only place I use a torque wrench when working on an engine (oh, actually on the head bolts also). I believe yours should be 40-45lbs. If you shear it one or more times you will probably toast either your crankshaft or your flywheel so get it right next time. Get the proper key and use a torque wrench.

and btw, if you want to stop the bubbling at the split case, I had that problem once and am lazy so tried several things not wanting to split it and found that JB weld worked nicely to stop the bubbling. If you can access the area.

 

[BSDenning]

Re: 1957 18hp Evinrude crankcase leak

ok... I've learned my lessen. I will never put a flywheel nut on without my tourchwrench again.

I wonder if my flywheel is damaged. It seems to be nicked where the slit is for the key. Will the flywheel from my 1956 Johnson 10hp work on this motor?

 

[F_R]

Re: 1957 18hp Evinrude crankcase leak

No.

 

[BSDenning]

Re: 1957 18hp Evinrude crankcase leak

I have ordered 2 new flywheel keys from Laing's Outboards. Once I get them in the mail, I will install my flywheel using my tourch wrench and hope for the best. If it shears another key, then I guess I'm looking for another flywheel.

 

[jmendoza]

Re: 1957 18hp Evinrude crankcase leak

Be sure the timing is correct, too much advance, or one cylinder way out of time will also cause you to shear a key.

 

[BSDenning]

Re: 1957 18hp Evinrude crankcase leak

Be sure the timing is correct, too much advance, or one cylinder way out of time will also cause you to shear a key.

Please advise me on how to adjust the timing on this motor. One of my original thoughts was that the timing could be off. But, I couldn't figure out any way of adjusting the timing.

 

[tx1961whaler]

Re: 1957 18hp Evinrude crankcase leak

The timing is set by the points. Timing on these is not really adjustable, or necessary. Set the points to open 0.020" at the very top of the cam, and it's timed.

 

[BSDenning]

Re: 1957 18hp Evinrude crankcase leak

The timing is set by the points. Timing on these is not really adjustable, or necessary. Set the points to open 0.020" at the very top of the cam, and it's timed.

Yeah, everything I've found has shown that you can't really adjust the timing on this motor. I know the points were set correctly.

 

[BSDenning]

Re: 1957 18hp Evinrude crankcase leak

I took the flywheel off today and examined it with my father-in-law. We agreed that the flywheel keyway has been damaged and that is probably the cause of my problems. Now, I need to find a new flywheel.

 

[tx1961whaler]

Re: 1957 18hp Evinrude crankcase leak

I took the flywheel off today and examined it with my father-in-law. We agreed that the flywheel keyway has been damaged and that is probably the cause of my problems. Now, I need to find a new flywheel.

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