1959 35HP SuperSeahorse

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skybum

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This engine is giving me a headache. I had it running nicely in the bucket. When I got to the lake it would still not develope full power. Here is the weird stuff, when the engine is advanced to full throttle it sounds like it is only developing about half its power. Once in a while it starts to surge like it wants to go and then not. In reverse the engine will produce full throttle. Like I said in the bucket it growls like no ones business but when on the water it just wont go! Any help is appreciated!!! Thanks.
 
JB

JB

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Re: 1959 35HP SuperSeahorse

It's running on one cylinder, skybum.

With little (like reverse) or no (in the bucket) load it will sound good on one cylinder. Put a load on it and it falls flat.

Probably one of the magnetos is failing.
 
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skybum

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Re: 1959 35HP SuperSeahorse

So a ignition rebuild is in order you think?
 
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skybum

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Re: 1959 35HP SuperSeahorse

I think that it is the lower cylinder then because when I disconnected the leads the top one not only shocked me but killed the motor, and the lower cylinder lead did not shock me and did not even change the rpm frequency of the motor!
 
F

F_R

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Re: 1959 35HP SuperSeahorse

Do you know the history of the motor? Those magneto coils are notorious for cracking and going bad. If they have not already been replaced, they are bad. Yes, you need to do an ignition inspection and repair.
 
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skybum

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Re: 1959 35HP SuperSeahorse

I do not know the history of the motor unfortunately. It is however in good shape overall. I have been debating pulling it apart this winter and rebuilding it and or replacing parts that need to be. I spent the majority of summer redoing the boat and did not have much of a chance to work on the motor. I am a little uneasy with the year of the engine and trying to find parts for it. The debate continues either tear down and rebuild or buy a different motor thats newer and easier to come buy for parts any experience with these older motors?
 
F

F_R

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Re: 1959 35HP SuperSeahorse

If the present problem is the only issue, don't give up on it. Those are tough ol reliable motors. Common service items like ignition and carburetor kits and water pumps, etc. are readilly available right here at iboats.

Check the compression. If that's OK, fix the ignition and enjoy it.
 
R

R.Johnson

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Re: 1959 35HP SuperSeahorse

On an engine of this age, before spending any money, do a compression check. That is simply a given on any outboard, new, or old.
 
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itstippy

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Re: 1959 35HP SuperSeahorse

If the compression check shows readings above 60 per cylinder and both are within 10% of each other you probably have a very rewarding project on your hands. 80-100 lbs would be ideal, but 60 is OK if they're close to each other in reading. Lower than that and you're looking at too extensive a project.
You probably won't find an outboard mechanic to do the work. There's just no money in it for them. If you're handy, though, you can do the work quite easily yourself. Parts are dirt cheap (as far as anything is "cheap" these days). Those old Big Twins are like old tractors. They burn a lot of gas. They pollute. They're built well. They run forever. They're easy to work on. They have heart. They have real torque at low RPM's. Do the compression check And post back.
 
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skybum

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Re: 1959 35HP SuperSeahorse

Thanks to all for the expoditious responses! I will look into doing a compression check before anything else! Anyone care to give me an idea of the proper procedure for doing a compression check. I have a manual but am still a little unsure of how to get a reading. Thanks.
 
tashasdaddy

tashasdaddy

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Re: 1959 35HP SuperSeahorse

it's best to use the compression guage that screws into the spark plug hole. remove plug, insert guage, set throttle at wide open. turn engine over 4 cycles. note reading on guage. repeat for each cylinder, and report back here. i use a guage that has a rubber hose, it makes it easier to get in around the shroud.
 
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F_R

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Re: 1959 35HP SuperSeahorse

Crank the motor with the electric starter if it has one. Otherwise disconnect the compression relief on the manual starter because it will give you false readings. Crank it till the reading goes as high as it will, 4 may be enough but more won't hurt. No need to have the throttle open on a two-stroke, if fact that prevents you from cranking it with the key switch.
 
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skybum

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Re: 1959 35HP SuperSeahorse

Thanks to you all for the help, I will get that done straight away and report back!
 
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skybum

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Re: 1959 35HP SuperSeahorse

Alright I did the compression check and the #1 Cylinder reads 118 PSI and the #2 Cylinder 108 PSI. The #2 is the one that I suspect having the bad ignition lead. Would this have anything to do with the fact that it is also reading a bit lower than the #1 cylinder since it has not fired in a while? What do you all think? Thanks!
 
tashasdaddy

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skybum

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Re: 1959 35HP SuperSeahorse

Any idea how to get the compression back in the #2 cylinder. Do you think it might be bad rings or just possibly some buildup in the cylinder from not firing? I will get started on the ignition, from what I have read on here and in the manual it is leaning towards a magneto gone bad who knows till the flywheel comes off. By the way the gear on the top of the flywheel is missing (the one for the generator which is not installed), is there any other reason to replace this gear unless I wanted to try and find a generator? Thanks for your replys! This is a great website!
 
tashasdaddy

tashasdaddy

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Re: 1959 35HP SuperSeahorse

i'm not worried about # 2 at this time,, if it doesn't come back after the decarb, then worry. it will probably run for a long time like it is. the compression is just within the "GUIDE LINES" 9.1% difference. it's just a rule of thumb.
 
F

F_R

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Re: 1959 35HP SuperSeahorse

Almost all of those generator gears fell off the early flywheels. No need to be concerned as long as you don't have a gen.
 
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skybum

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Re: 1959 35HP SuperSeahorse

Thanks to everyone for their help! I am going to be on the road for the next week, however when I return the ignition will be one of my first priorities! I will post back with results. Hopefully we can get this sweet machine running strong again!
 
Scaaty

Scaaty

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Re: 1959 35HP SuperSeahorse

I stopped reading this thread after JB's post.
Coils are JUNK...Don't just replace one. I got a 58 35 sitting here, and you need new coils..do the whole ING system, and the rest will outlast you..
 
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