1974 Johnson 50hp?

[Texas Prowler]

Hello,
I'm back with another outboard question. I'm going to look at a 74 50hp John in a couple weeks. Is this a good outboard year? Seller says it runs and has 140psi on the cylinders. Considering the compression how many hours would you say this outboard has on it given routine maintenance? Someone on another forum recommended putting in boysen reeds and one step larger jets suggesting the outboard would wake up. I'm all about more horses and better idling with the same weight. I think(I know little about outboards) hypothetically it will increase the oil inside the outboard and extend the life of it. Im probably wrong so correct me if so. This outboard will be used on a 59 run about styled 14ft tin for fishing in big lakes. It's the max hp for the tin. The same seller has 40hp outboards as well, but I'm a hp junkie...more the faster. No replacement for displacement...is this a good outboard? Would you mod it?

 

[Faztbullet]

Reeds do not make horsepower....and the 74 is powerhead rated so it only about 40-48 hp at prop

 

[Texas Prowler]

Thank you fazt. Would you buy this outboard? I'm in need of an outboard tip get this Tin powered. I'm fine with its hp. I'm just looking for an outboard besides a merc...

 

[flyingscott]

It's a good outboard make sure the lower unit is good and shifts. Test drive if possible and depends on price just had an 85 40 hp sell for $500 by me. That is a more powerful motor and more parts availability.

 

[Texas Prowler]

Thank you flyingscott. You've been a tremendous help. I'll just keep it all stock with no modifications. Do you have an idea what the compressin was trim the factory on this motor?

 

[flyingscott]

Compression should have been 150 psi new. I cannot stress enough about the lower unit. Lot of NLA parts and used ones are hard to find.As far as boyesen reeds. I have them in my boat they are not a performance item it idles better but that's about it. I use them because my motor ate a reed and I don't want that to happen again. As far as putting a bigger jet in to get more oil in the motor not really how it works. A 2 strk motor at 50-1 is very well oiled motor.

 

[Texas Prowler]

Thank you. I most definitely will check the lower unit for proper operation. I'll check the oil while I'm there. What tools should I bring besides a compressin tester?

 

[Texas Prowler]

Ok i just read your first post again and you say the 85 40hp is more powerful? Wow! I didn't think that was possible.

 

[flyingscott]

THe 74 is a 41.5 CID motor and HP is rated at the powerhead. The 1985 motor is 45 CID and HP is rated at the prop. So power out put at the prop is probably similiar but the 85 probably has better low end torque. No replacement for displacement.

 

[Faztbullet]

Would you buy this outboard?

Only if I could lake test it...These motors can have great compression and be worn out as they wear the skirts of piston.This results in idle and bogging problems won take off and dying if trying to troll.You stated you don't want a Merc but a 40Mag/45 or classic 50 will run better than the OMC and they will have trim where the others wont..

 

[F_R]

The '74 was a breakthrough in twin cylinder design and worked very well. If there was a "bug" in them, it was that some broke pistons at the top ring land. But that most certainly would show up on a compression test.

 

[Texas Prowler]

THe 74 is a 41.5 CID motor and HP is rated at the powerhead. The 1985 motor is 45 CID and HP is rated at the prop. So power out put at the prop is probably similiar but the 85 probably has better low end torque. No replacement for displacement.

Thank you! Hopefully he has a couple newer outboards.

 

[Texas Prowler]

Only if I could lake test it...These motors can have great compression and be worn out as they wear the skirts of piston.This results in idle and bogging problems won take off and dying if trying to troll.You stated you don't want a Merc but a 40Mag/45 or classic 50 will run better than the OMC and they will have trim where the others wont..

I've been burnt by a merc once.I've spoken with a long time merc mechanic and he said stay away from the two cylinder models and that the 3 and 4 cylinders and bullet proof. I've found a 80s 50hp merc with 130on the cylinders with t&t but not sure if i want to take that chance... The choke rod is missing and the link for the carbs is broken and taped together.I'll see if he has any newer omc outboards if not I will see if I can get this running in a garbage can this week.

 

[Texas Prowler]

The '74 was a breakthrough in twin cylinder design and worked very well. If there was a "bug" in them, it was that some broke pistons at the top ring land. But that most certainly would show up on a compression test.

Awe man that doesn't sound good....

 

[Texas Prowler]

Well guys after the hours of searching the boat yard and going through at least 60 outboards i didn't buy anything... The guy has a lot of parts motors but nothing complete and running. I'm going yup another boat shop tomorrow with hopes of finding a good outboard.at this point I'm ok with 35-50hp outboards... I guess we will see what tomorrow brings...

 

[flyingscott]

Try craigslist you may need to be patient but the deals are out there.

 

[Texas Prowler]

Yep I've been watching the local CL. Hopefully I'll find something soon.

 

[Texas Prowler]

Well guys i got a 73 johnny with 160psi wet. Little more info this evening

 

[phillnjack2]

1973 !!!!!! you realy are a sucker for punishment. I hope you got plenty of spare cash lying around for spares.

 

[Texas Prowler]

Really??? It has awesome compression and he gave and still has any part i could need for free... What's so. Bad about this one? Omg got it at a stupid great price and spare parts plus steering cables, steering wheel, controls, rpm gauge and other stuff.

One issue is it doesn't have spark but if got the complete ignition system from another to swap parts. The stator reads ohms so I'll start by changing the power pack unless you guys have another idea. Like i said I've got and have access to all the parts i need for free... Thanks. After that I'll need help syncing the carbs after i soak them in something.
Thanks guys!