Recommendations for upgrade from 40 hp Big Twin?

[baytonemus]

After a few weekends of boating with my recently restored 1960 Flying Crest (aluminum) and 1963 Big Twin 40 hp motor, I've come to the conclusion that I need a little bit bigger motor. Even with only three of us in the boat (<450 lbs total) pulling a skinny 16 year old on a tube, it just doesn't quite develop enough speed. I have not tried a different prop, although I might have to soon. I had a spun prop yesterday...

I'd like to have a motor that's close to the age of my boat just to keep the whole vintage vibe intact. I'm not at all afraid of a project but I'd like to pick something that will be reasonably "maintenance-friendly" and for which parts can be found.

I've seen quite a few of the early '60s Johnson V4s. Are all of those short shaft motors? I need a long shaft. I actually extended the Big Twin I have now.

I'm seeing a few of the ~'63-67 75 hp Evinrudes, too. I think my boat can handle up to an 80 horse motor.

There's a guy in town here with a '71 Johnson 60 hp motor that has not been running for a long time. I could buy that one pretty cheap. However, I assume that it's one of those electronic shift models and I've heard that some parts for those are really hard to find. Skeg is damaged on that one.

Any input appreciated. Thanks!

 

[Bob_VT]

Re: Recommendations for upgrade from 40 hp Big Twin?

Avoid the electric shift models like the plague !!!! Parts are NLA and what few you can find will destroy your wallet.

What is your boat rated for? It may not be a good idea to upgrade just the motor but, upgrade the entire boat.

I have an older Starcraft and MANY of us here on iboats do........ mine is rated for a 85 hp and the model up from mine is rated for 150 hp......... plenty of power for tubing and skiing.

As a kid I spent many many many hours skiing behind a 33 hp evinrude which was "adequate" at the time.

 

[mstahl1171]

Re: Recommendations for upgrade from 40 hp Big Twin?

I'd try another prop before I give up on the big twin. Trim the motor all the way down too. When I was a kid we would ski behind a 1962 16' Revell Craft mahogany wood boat with 4 people in the boat. Im sure it weighed more than your Flying Crest. Getting up on a salomn ski was hard but if you did 2 skis and dropped one after you up on plane....plenty of power...boogie boards and tubes no prob.

 

[jay_merrill]

Re: Recommendations for upgrade from 40 hp Big Twin?

I wouldn't be so sure that the mahogany boat is heavier than the aluminum boat. This is especially true if its a cold molded boat. Mahogany is a very strong wood, but its also very light.

I agree that the OP should try a different prop, before giving up. Available prop pitches for that motor range from about 11" to 14". Props are hard to find, but with a little searching, they can be found.

I would be careful of the 1971 60hp motor, but not as much for the electric shift, as for the battery CD ignition in it. No doubt that the electric shift system (hydro-electric) can be problematic, but if they work and are maintained (proper gear oil, seals, etc.), they can last quite a long time.

To me, the biggest problem with the battery CD ignition system, is the distributor, which is both wearable and no longer available. The system is also said by some, to be weak in general.

 

[baytonemus]

Re: Recommendations for upgrade from 40 hp Big Twin?

Thanks for your input, guys! A few clarifications...

What is your boat rated for? It may not be a good idea to upgrade just the motor but, upgrade the entire boat...

...As a kid I spent many many many hours skiing behind a 33 hp evinrude which was "adequate" at the time.

The boat I'm keeping because it's been in my family since new. I learned to ski behind it at my grandparents cabin. In the 50s and 60s my dad and grandpa had a Crestliner and Johnson dealership, so they actually drove to Little Falls and picked it up personally. This has been a labor of love of me. Not the original motor, though. We had a Johnson 40 hp on it.

I'd try another prop before I give up on the big twin. Trim the motor all the way down too.

I actually did move the motor from the 2nd lowest to the lowest trim position yesterday. Not sure I could tell a lot of difference. Is it possible that the prop was beginning to slip or does that just happen all of a sudden?

I agree that the OP should try a different prop, before giving up. Available prop pitches for that motor range from about 11" to 14". Props are hard to find, but with a little searching, they can be found.

I wasn't aware that these are difficult to find. However, I just searched the iBoats store and none of the three different pitches I clicked on were available. Are we talking about only old props being available? Also, how can I determine what the pitch of my current prop is ...and can it be repaired?

I would be careful of the 1971 60hp motor, but not as much for the electric shift, as for the battery CD ignition in it. No doubt that the electric shift system (hydro-electric) can be problematic, but if they work and are maintained (proper gear oil, seals, etc.), they can last quite a long time.

To me, the biggest problem with the battery CD ignition system, is the distributor, which is both wearable and no longer available. The system is also said by some, to be weak in general.

Maybe I should buy this one and part it out. I'll bet I could get it for $100 or less.

 

[mstahl1171]

Re: Recommendations for upgrade from 40 hp Big Twin?

According to my OMC propeller Selection Chart fo 40HP you should be running 10-3/8" dia, 13-1/4" pitch OMC p/n 378579 You can try searching ebay or call Fairwinds Marina in Annapolis MD. (410) 974-0758. He has a large inventory of new and use props for these old gems. I purchased a use prop from him last month...$12.00...$50.00 to send out and have prop reconditioned.

PS...I will scan my chart and post for all to use.

 

[mstahl1171]

Re: Recommendations for upgrade from 40 hp Big Twin?

OMC Chart is too large to post. If you would like a copy send me a PM with your email address and I will send you a copy

Mark

 

[baytonemus]

Re: Recommendations for upgrade from 40 hp Big Twin?

The one shop in town that can re-hub props says that a hub is no longer available for my prop. So, I went to the boat salvage yard/repair shop here and found a replacement prop in OK shape - OMC #380637. This was originally one option for the lower unit I have on this motor. It's a 10 1/2 x 12. We'll have to give it a try and see if it's any better than the one I had on there.

The mechanic at this place (which is the only shop locally that will still work on older stuff) says that he is not crazy about any of the Johnson/Evinrude 4 cylinder 60 and 75 horse motors from the 60s. He said that some critical parts including a pinion bearing for at least one model is no longer available. That doesn't sound too promising...

 

[jay_merrill]

Re: Recommendations for upgrade from 40 hp Big Twin?

I'd stay away from the 60s model year 4 cylinders too. Parts availability is an issue, plus they are terrible on fuel consumption.

 

[baytonemus]

Re: Recommendations for upgrade from 40 hp Big Twin?

Had a chance to try the "new" prop on Sunday. I would have to say it felt like a step backwards with regard to speed. There were only two of us in the boat and we weren't pulling anyone, so it might be even worse. At the very least it wasn't an improvement.

It seems like it would be helpful to have a tach to better evaluate where things are at. Not sure how to install one, though.

 

[BonairII]

Re: Recommendations for upgrade from 40 hp Big Twin?

Installing a tach seems somewhat easy from what I've read. A tach and GPS will def help you figure out what prop is best. I use my iPhone with a Speedo app to determine my mph.

 

[lindy46]

Re: Recommendations for upgrade from 40 hp Big Twin?

Had a chance to try the "new" prop on Sunday. I would have to say it felt like a step backwards with regard to speed. There were only two of us in the boat and we weren't pulling anyone, so it might be even worse. At the very least it wasn't an improvement.

It seems like it would be helpful to have a tach to better evaluate where things are at. Not sure how to install one, though.

If your original prop was 13-1/4" pitch, yes, the 12" will be slower but give you more power for pulling skiers/tubers. It's always a compromise.