Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

[Chaparralbob]

I have a 1962 model 5524R Evinrude 5.5 HP "Fisherman". I have the parts diagram, but I don't see the main bearings listed anywhere. Are these replaceable?

If so, can someone please help me with the part numbers?

All of the parts diagrams I have found are missing any reference to the main bearings. They are bronze bearing inserts, very much like what I would expect to see in a regular car engine. It makes me wonder if they are not replaceable.

I am reluctant to do anything with them until I know if they are replaceable. The middle bearing has a fairly deep scratch in it. The corresponding journal on the crankshaft looks fine, so I'm not sure how the bearing insert was damaged.

Thanks for helping with this!

 

[F_R]

Re: Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

They are cast integrally when the block was poured and thus are NOT replaceable. That's why there is no part number.

 

[Chaparralbob]

Re: Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

Thanks for the answer F_R!

I was afraid that might be the case. Other than the scratch in the middle bearing, everything else looks good. I guess I will just have to go ahead and run it as is. I'm guessing the cost of a new block would be too high to make this economically feasible.

I appreciate the answer!

 

[boobie]

Re: Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

Look at the positive side, the scratch will just trap more oil for lubrication.

 

[F_R]

Re: Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

How deep, and what direction is the scratch? If it is deep, and vertical (joining the upper and lower crankcases), it will transfer the crankcase compression back and forth between the two chambers. If that is significant, it will affect the starting and idle.

If it is a circular scratch, not joining the two chambers---not to worry.

 

[1946Zephyr]

Re: Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

How did it get scratched?? Was it done by a nick in the crankshaft?

 

[Chaparralbob]

Re: Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

The scratch is in the direction of the crankshaft rotation. It is just deep enough to see shiny metal, apparently the backing of the bronze coated bearing shell.

I don't know how it got there! I just acquired this engine, and it hasn't run in 20 years. There is no corresponding scratch in the crankshaft, so I can't tell you how it happened. I had low compression in both cylinders, and thought the rings might have been frozen. And, I just generally wanted to see the condition of the engine before I spent the time, trouble, and money to fix it up. With the exception of the scratch in the center bearing, and some very fine sand blocking the thermostat and some water passages, the engine looks damn good!

I had no idea that older outboards used plain bearings rather than needle bearings! You learn something every day.

Thanks to Boobie, F_R, and 1946Zephr for your answers and help! I appreciate the answers very much!

 

[Faztbullet]

Re: Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

Thats why people need to check oil/fuel mixtures as these type engine wont live long at 50/1 mixture......

 

[Chaparralbob]

Re: Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

The most reasonable mixture I have read for this engine is 24:1. Several posts have mentioned that the original mix was 16:1 with 30 weight motor oil. Supposedly, with TCW-3 oils, 24:1 is adequate.

Does anyone have any opinions on this?

Fatzbullet - thanks for the comment. I'll pay close attention to the mixture!

 

[F_R]

Re: Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

Hoo-boy do people have opinions!! Mine is use 24:1 with TCW-3 oil and regular unleaded.

 

[1946Zephyr]

Re: Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

Yea, I would run 24:1 on a 5.5 that late. The 50's vintage, I would give 16:1 to. I would mic out the bearing journals and if they measure out good, then it should be fine to put it back into service. If the crank looks good, then you're good to go. The ideal clearance on the crank to bearing is .0015 - .002

 

[Chaparralbob]

Re: Bronze Main Bearings on 1962 Evinrude 5.5 HP - replaceable?

Thanks F_R and 1946Zephr!

I'll post when I get everything back together and running.