Johnson stalls beyond 2000rpm, but only in the water

[tglass]

I am troubleshooting a 73 Johnson 65 with very low hours. It runs fine out of water with a <br />flush kit, but in the water it will not run up beyond 2000 RPM, in gear, before it chokes out. <br />With the flush kit it engages and runs up nicely. Any help will be appreciated.<br />TG

 

[tglass]

Re: Johnson stalls beyond 2000rpm, but only in the water

An addition to the above, I have tried a second set of plugs, I am using one new and have tried one old fuel line, as well as new gas.

 

[BKool68]

Re: Johnson stalls beyond 2000rpm, but only in the water

The high speed jets on your carbs may be clogged.

 

[Bob_VT]

Re: Johnson stalls beyond 2000rpm, but only in the water

Check the spark on all cylinders. If a motor is not under load it will still rev up and actually sound okay.<br /><br />Check your plugs as well as the carbs. <br /><br />Bob

 

[tglass]

Re: Johnson stalls beyond 2000rpm, but only in the water

BK and Bob, What is best to clean the carb with? Automotive type cleaners or others?<br />Thanks

 

[BKool68]

Re: Johnson stalls beyond 2000rpm, but only in the water

An automotive cleaner will work but not just the spray stuff. You need to disassemble them and soak them. It is also good to run a piece of wire or such through the high speed jets. Also be certain to replace the float needles and seats.

 

[tglass]

Re: Johnson stalls beyond 2000rpm, but only in the water

Thanks BK. Last night I did find what is probably the core of the problem. I did the plug pulling routine, and did loose RPM's on all three plugs. So the cyl's are all firing. But I continued to hear an arcing sound even with the boots back in place. Seems there is a hairline crack in the green casing around the top ignition coil, and the arc was grounding on the coil mount. I covered with vinyl electrical tape and stopped it. I think I can repair the case with a thick epoxy resin and probably be OK. What do you think?<br />TG

 

[Beernutz]

Re: Johnson stalls beyond 2000rpm, but only in the water

Try something flexible, like "Liquid Electrical Tape". Epoxy will just crack again on the seam.<br /><br />This is a common failure. Fire your motor up at night (in the dark) with the cowling off, and look carefully at all the coils to see if others are arcing.

 

[tglass]

Re: Johnson stalls beyond 2000rpm, but only in the water

Ah, Beernutz huh? <br />Thanks, I did consider that, (firing her up at dark, a common practice when I am working on auto's), but then I thought of our neighbors through the woods in the $600K houses. They may not approve. I'll wait until someone's having a good party!<br /><br />The vinyl tape is a good idea. I am curious if anyone has experienced the same problem with the cracked coil cases, and had a similar inability to run the motor up, but only under load?<br /><br />Thanks always.

 

[clanton]

Re: Johnson stalls beyond 2000rpm, but only in the water

Common problem with this coil, should be replaced, but I have seen the cracks fill with everything from dry dirt to 5200. I think it overworks the powerpack.