40hp 1962 Johnson Seahorse electromatic, no speed Help!

[paintdan85]

Hey guys,

This is the first time to the forums but quick but tricky question for you all.
Last year I bought a 40hp 1962 Johnson, and seloc manual. Rebuild and painted the whole motor, also made a new wiring harness for it, stuck it to my fiberglass 14' and only getting 10-12 MPH on my G.P.S.. Here’s the tricky question, the motor is revving good high speed, running a 50:1 gas ratio, replaced the prop with a new one because of the old rubber in the prop, I am using type C oil in the lower. Have no problem with shifting and engine revving, just not getting any speed out of it. I just tore apart the lower just to make sure everything got put together right and as far as I can see it is. While apart I put 12v to each lead and putting vise grips on the motor shaft and prop shaft, I can get it to turn like the springs and magnets are working fine, but not sure under high load if it might be slipping??? Also I don’t have the generator hooked up, but the batteries have a full charge when I go out to the water so I don’t think is a amperage problem.

So the big question is, dose anyone have any idea's what might be wrong??? Should I go out and buy a new front magnet, spring and spindle and try there, which would be about $300 to $400??? Any and all help would be greatly appreciated!!! The seloc manual says to test the magnet, if you put your meter on ohms you should pull a 4.5 to 6.5, mines running a 9 in front and an 8.5 in the rear, reverse works fine, is that the problem?.

Thanks guys!
Dan

[paintdan85]

Hey guys,

Also the boat is a 14' glassmaster also 1962 light load with 2 people in boat no gear just crusing, again its a project boat so theres only 2 seats and thats about it no more the 1000 Lbs all together both people motor and boat. again engine runs fine at WOT no bogging or anything, and already replaces the prop due to the rubber in the hub. Its a side console set-up, the motor cavitation plate is even with the bottom of the boat so the prop is fully below the boat to. So again any help would be greatly appriciated!!!

[tx1961whaler]

I'm going to think outside of the box here:
Check to see if the new prop is slipping.
Check the spark to see if you are running on only 1 cylinder.
Make sure the carb butterfly is opening up all all the way at full throttle.
When the springs broke on my electramatics, I certainly don't remember getting 12 mph out of it. I'm thinking your gearcase is OK.

[lindy46]

How is compression?

[paintdan85]

compression is 128 on #1 and 130 on #2, The old prop I marked to see if it was spinning and the marker line, lined right up like it wasn’t spinning, but I bought a new prop just to make sure, visually looking at the springs they look intact, they don’t look broken, I was thinking they where slipping but not sure. And if the motor was firing one one cylinder would the motor still run fine with out hesitation at wot? I haven't checked since I rebuilt it that could be the case ill have to check it out, as for the butterfly in the carb yes it is opening all the way.



Thanks
Guys

[paintdan85]

Ok guys, just checked and i do have spark on them both the plugs are gap'ed at .35, I rebuilt the whole system new coils condensers points wires and plugs, like i said earlyer the motor sounds like its running fine at wot and thats why i though it might be the lower unit... im wondering if i just got a dud haha

[jimmbo]

In 1962 I believe the Carb still had an adjustable high speed needle. Perhaps it is out of adjustment. What are the pitches on the old prop and the new prop?


As a point of info, the oil spec for a 1962 engine is 24:1 not 50:1