Well that tears it! It locked up!

[Gas Giant]

Re: Well that tears it! It locked up!

Ok experts - here is a question for you. I posted a want ad for a good used powerhead on aomci.org, and I got a reply from someone selling one for a '65 40HP. Is there any reason I couldn't run that powerhead? The price seems good.

 

[Mas]

Re: Well that tears it! It locked up!

I would still disassemble clean to see what you've got. If the crank & bearing are not pitted, I would hone and go for it.

Mas

 

[Gas Giant]

Re: Well that tears it! It locked up!

Got it completely disassembled. Pics will have to wait as both my digital camera and my cell phone decided that today was a good day to act up.

The crankshaft and rod bearing are badly pitted on the bad cylinder. They looked ok on the other cylinder, at least as far as I can tell. Ed Cole and his engineering group at GM didn't put any roller bearings in their connecting rods, hence I'm not too familiar with them.

I did manage to fight the piston out of the bad cylinder, and after an initial hone things started to look up - the rust came out. It was getting excited, but then I noticed the huge 2 inch scratch running down the cylinder wall. That ain't gonna hone out.

So, I definitely need some machine work. Anyone care to guess if that '65 powerhead will work for me?

 

[HighTrim]

Re: Well that tears it! It locked up!

What is the model number of the 65?

Without looking into it, I cant think offhand of any reason why it would not work. Check things like base gasket part numbers, etc... on marineengine.com

 

[Gas Giant]

Re: Well that tears it! It locked up!

Hmm.....I'm not seeing a lot of similar part numbers......

 

[1946Zephyr]

Re: Well that tears it! It locked up!

Yes, a '65 model will work all the way back to '58. I once mounted a 1968 Lark X powerhead on a 1959 RDS-21B and it worked out great. It may be a better option anyhow, because the 1960-61 model 40's had issues with the cranks, hence the reason of the re-design in 1962.

 

[F_R]

Re: Well that tears it! It locked up!

There are many small changes. You may have to do some component swapping. Probably the biggest is the automatic choke. One has a water heated choke and one has an air heated one. And the plumbing that goes with them.

 

[1946Zephyr]

Re: Well that tears it! It locked up!

Yep, very true. One other good thing too, is that '65 model powerhead, runs on 50:1 mix as apposed to the 24:1 mix.

 

[F_R]

Re: Well that tears it! It locked up!

Oops, BIG difference here. The 1965 has a bigger crankshaft, therefor it takes a different flywheel.

 

[tx1961whaler]

Re: Well that tears it! It locked up!

There are many small changes. You may have to do some component swapping. Probably the biggest is the automatic choke. One has a water heated choke and one has an air heated one. And the plumbing that goes with them.

...and neither one worked very well.

 

[1946Zephyr]

Re: Well that tears it! It locked up!

Oops, BIG difference here. The 1965 has a bigger crankshaft, therefor it takes a different flywheel.

Exactly. The '62 and newer had a lot of major changes to the powerhead, and the crank and head being a couple of them. From what a long time mechanic told me, the 1960 - 61 was merely a punched out 35 and they were notorious for twisting the cranks apart, in the event of a runaway situation. A lot were even recalled. Aparently not many went back, because I still see a lot of them out there. LOL

 

[Gas Giant]

Re: Well that tears it! It locked up!

Oops, BIG difference here. The 1965 has a bigger crankshaft, therefor it takes a different flywheel.

Does this also mean that the armature plate and all the ignition parts mounted on it also need to change?

 

[1946Zephyr]

Re: Well that tears it! It locked up!

the armeture plate should be the same

 

[Gas Giant]

Re: Well that tears it! It locked up!

Here's a new angle...

I found a '63 BigTwin sort of near me. Its currently attached to a little aluminum runabout. Assuming that motor has good compression, is there any reason I couldn't swap out the carb, lower unit, and ignition setup from my '61 motor to this one?

 

[F_R]

Re: Well that tears it! It locked up!

That stuff will swap, but the flywheel won't.

 

[Gas Giant]

Re: Well that tears it! It locked up!

The '63 is a complete motor, so hopefully it has a flywheel on it.... As long as the carb, ignition, and lower unit will swap from my old motor, I should be good to go, I assume. I'll call them in a bit to find out the dealy-o.

 

[Mas]

Re: Well that tears it! It locked up!

If the "parts motor" is complete...why not just try to get that one going and for get all the swapping?

Mas

 

[Gas Giant]

Re: Well that tears it! It locked up!

That's mostly what I am thinking (if it turns out to be a 40hp - still waiting to hear on the model no.). The main reason for swapping the parts is that I just rebuilt the carb, replaced the entire ignition and resealed the lower unit with a new impeller on my old engine, so I know those parts are good.

 

[1946Zephyr]

Re: Well that tears it! It locked up!

If it is a 63 Big Twin, then it is a 40hp.

 

[Gas Giant]

Re: Well that tears it! It locked up!

Man you guys know a lot!

I'll get the model number first; looking more carefully at the ad, it says the boat is a '63, but doesn't specifically say what year the engine is.