1961 Johnson 40 HP Seahorse trouble

First off I would like to disclose to everyone that I am not much of a motor head and this is really my first attempt in getting a motor running. I purchased this motor from a guy who said it hadn't ran in a few years but it turned over pretty well. I got it home and started her up and she ran decent considering a tank of old gas. I refreshed the gasoline and couldn't get her to turn over. I read some books and flushed the fuel lines, changed fuel filter and rebuilt the carb with the original kit. I am not not able to get it to start with the choke on in neutral, if I start it at high throttle it will turn over but soon die out. I am guessing the adjustments for the high/low speed rich/lean could be off or perhaps my idle adjustment. Anyone know how to restore the settings on these bad boys? Oh, I also changed out the spark plugs as well. I am at a loss for more ideas...any help would be greatly appreciated!

Re: 1961 Johnson 40 HP Seahorse trouble

hookups08 said:

I am guessing the adjustments for the high/low speed rich/lean could be off or perhaps my idle adjustment. Anyone know how to restore the settings on these bad boys?

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Welcome to the iboats.com forum. The experts here, which I am not, can answer any question about your boat, motor and trailer. The FAQ's are full of very good info. The link below is a "how to" adjust your carb settings. Plenty of help here if you need more. Good luck!

http://forums.iboats.com/showthread.php?t=167352

Re: 1961 Johnson 40 HP Seahorse trouble

My engine has fixed high speed jets so I don't know about the adjustment on them. As far as the low speed, turn your needle valve all the way in to seat, then back it out 1 1/2 turns. That will give you a starting point to adjust. If the engine starts and runs there, keep turning your needle screw in in small increments, giving the engine a few seconds to respond until the engine kinds sputters/almost backfires, then back it out 1/4 of a turn. That should be your sweet spot.

Re: 1961 Johnson 40 HP Seahorse trouble

I have tried this method and this is sort of assuming I can actually get the motor to turn on and actually run for a minute. I have set them in and backed them out and I still cannot get my engine to turn over. What about the idle adjustment, what is a good starting point for that? Hey, I really appreciate your guys' help though, I was about to drown myself before I found this site!

Re: 1961 Johnson 40 HP Seahorse trouble

Forget about those adjustments for now. What you need to do is an orderly, sensible troubleshooting of all systems.

OK, we know it had old gas and you supposedly rebuilt the carburetor. What did you do with the ignition system? Have you inspected it at all? Also, do you even know if the motor is capable of running? By that, I mean have you checked its general condition, including a compression test?

Carburetors are not the magic ingredient. Only one part of the three things required to make any engine run: Compression, Fuel and air in the right amounts, and ignition. Add to that, on a two-stroke, crankcase compression.

Re: 1961 Johnson 40 HP Seahorse trouble

I have pretty much ignored the ignition system because I know it can start. Correct me if I am wrong but if this system were to be shot, the motor would not start at all. I am getting it to turn over every once in a blue moon so I know it is capable meaning I think my compression and ignition are not the issue. Once again, I am by no means an expert, just my reasoning for not checking those systems...