1961 Evenrude 40, Water in Lower Cylinder

Hi All,

I just bought an old boat with a motor that looks to be in realy good shape except that the crank shaft will only turn a very small amount before "sticking" in both derections (it gets about 1/8" of piston travel).

The motor is a 1961 Evenrude 40Hp (Big Twin) M/N: 35022

Prev owner said that eingine used to run but got water in lower cylinder somehow. He said that he put diesel fuel in cylinder once he discovered water.

After getting it all home and making a closer inspection the motro still looks really good. I can find no discolored paint on the head or block, so hopefully not overheated. Lower spark plug looked good, no rust or discoloration.

It seems a sheme to not try to save this motor becoming a parts donor but need to figure out how it got water in the lower cylinder.

I did a search on this forum and did not find any threads, although I know that there has to be something about problem this out there already.

Can anybody offer any help with this or point me to some threads that have already discussed this?

What is/are the most likely causes of water in the lower cyl on the motors, and how are they best addressed?

I appreciate the help.

marty

Re: 1961 Evenrude 40, Water in Lower Cylinder

Take the head off and look at the cylinder walls. If it's simply surface rust, make a mixture of automatic transmission fluid and acetone. Mix it about 1:1. Squirt some in both cylinders. Lay the motor on the floor (on it's face) so that the cylinders are pointing up. Let that mixture sit in the cylinders over night and then gently try the flywheel (clockwise). Keep doing it for a day or two and the cylinders should loosen. Replace the head gasket (probable cause of water entering a cylinder) and see if it will start.

Re: 1961 Evenrude 40, Water in Lower Cylinder

Well, it ain't water in the cyl that's causing the problem.

I pulled the head off yesterday afternoon, the cylinders and pistons look really clean. No water, no rust, not even any wear ridge from the rings running in the sleeve. Both pistons moving with the crank when it turns what little that it does. Looks like I got "deeper" issues in the crankcase.

Buttoned it back up and Put the cowl on, it's a Project for another day.

Marty

Re: 1961 Evenrude 40, Water in Lower Cylinder

When you get back to it, pull the lower unit (gearcase) off and see it that is what is messed up. If the flywheel turns with the lower unit off, then you know that the problem is with the gears.

Re: 1961 Evenrude 40, Water in Lower Cylinder

Definately the problem is in the lower unit gearcase.

Pulled the lower unit off today, power head pulls thorugh very smooth and seems to have REALLY GOOD compression.

The lower unit, on the other hand has problems. The propeller shaft rotates nicely and shifts from Fwd-Neut-Rev well and smoothly, no indications of oil leaking from propshaft seal or housing gasket. Drive shaft will not turn, removed water pump housing and impellar, still no turn. Maybe just the pinion bearing is siezed.

marty

Re: 1961 Evenrude 40, Water in Lower Cylinder

Definately a cheaper fix.