RDSL-25D Johnson Seahorse 40

[Nebkroz]

Ignition problems:

1. Surges while idling
2. Backfires and stalls
3. Sometimes won't start at all (no spark on either wire - tested with air gap tester)

Any advice would be greatly appreciated...

Points? Coil? Distributor? Timing?

The motor is RDSL-25D Johnson Seahorse 40

Thanks!!

 

[mstahl1171]

Re: RDSL-25D Johnson Seahorse 40

sounds like you need to check all of the above..I'd do a complete tune up..new points...condensors...coils...also clean and rebuild carb. If you do a search you'll find plenty of tips for doing a tune up...pulling the flywheel.....parts can be purchased here on iboats..if you dont have a service manual...get one...ebay has loads of them...also can purchase from kencook.com

good luck...keep us posted

 

[jay_merrill]

Re: RDSL-25D Johnson Seahorse 40

Your motor doesn't have a distributor, It has a pair of ignition coils, condensors and points under the flywheel. A magnet in the flywheel completes the magneto ignition. I would hazard a guess that you need to replace a few parts in this system and possibly all of them. Once you get all of that sorted out and have the points properly gapped, your motor will be in proper time. You may have to sync the carb to the ignition advance, but that's about it.

Do yourself a huge favor and find a manual for your motor. It would be preferable to get an original factory manual, but if you can't find one of those, an aftermarket manual is better than nothing.

Above all, do not try to pull your flywheel with a gear puller. Use a harmonic puller (center pull from three bolts) only. When replacing, make sure that the crankshaft taper is clean of all grease/oil, that the woodruff key is properly installed and that the cranshaft nut is properly torqued.

 

[Nebkroz]

Re: RDSL-25D Johnson Seahorse 40

Thanks guys. I've ordered a manual. Should be helpful. I have the same motor for parts. The ignition system was working perfectly on that one (bad compression only). Not sure if I really want to take apart two motors unless replacing the ignition coils and condensors is pricey. I've cleaned out the carb and might need a new float...it is still the original wax coated cork. I have no reason to believe that the carb is contributing to the issues since all the issues I'm dealing with seem to be related to ignition....

This is a 1963 motor...I need to know if it is worth fixing, or when to call it quits. In your opinion, is this a motor that if I maintain once I get it running, will run for a while?

Thanks so much for the advice.

 

[mstahl1171]

Re: RDSL-25D Johnson Seahorse 40

I say fix it. They are easy to work on. Plenty of parts still available. With proper maint and care...these old gems will run on for many more years. I plan to hand my down to my son so he can enjoy for another 40+ years...

 

[jay_merrill]

Re: RDSL-25D Johnson Seahorse 40

I ran a pair of 1958 Evinrude Bigtwins on two different boats for a number of years, with good result. As long as the motor has good compression and is generally sound from a mechanical perspective, it can be fine and pretty inexpensive to own.