Dual fuel line Johnson bogs and overheats

[SpoonyWacker]

I have a '59 Johnson Seahorse 18 hp (FD-13), the kind with the dual fuel line and no fuel pump. It's bogging when under load and overheating after 10 min or so of running (dies and won't turn over for a few minutes). I'm not sure if the issues are related or not, but I assume if I'm not getting enough fuel, I'm also not getting enough oil, so likely leading to it running hot.

I've replaced the impeller and thermostat and rebuilt the carb. Any tips on how to diagnose this further? The tank appears to be holding pressure (there is still pressure in the tank several days after running it), but it is leaking a bit around the top gasket, so it doesn't appear to be completely air tight, but would that be enough to cause this?

 

[racerone]

Do a compression test and report the numbers you get.----Revisit your water pump work.------Hopefully you are running at 24:1 mix ratio.-------I doubt this is a fuel / oil issue !!!!

 

[Crosbyman]

have you check the thermostat lately ? does the FD13 have one ?
overheating ? or just heat just messing up the coils/condensers ? are they new ?

" won't turn over for a few minutes." ... as in stuck hard or no ignition ???

 

[SpoonyWacker]

Do a compression test and report the numbers you get.----Revisit your water pump work.------Hopefully you are running at 24:1 mix ratio.-------I doubt this is a fuel / oil issue !!!!

The compression was good a few months ago, but I'll check tomorrow and see if that's changed (man, I hope not). I have water coming out of the port on the bottom end (it sorta splatters out... Is that normal?)

 

[SpoonyWacker]

have you check the thermostat lately ? does the FD13 have one ?
overheating ? or just heat just messing up the coils/condensers ? are they new ?

" won't turn over for a few minutes." ... as in stuck hard or no ignition ???

I just replaced the thermostat a few weeks ago. The coils and condensers look pretty clean from the little hole in the flywheel (I haven't pulled the flywheel yet). I think they were new when I got the motor, but it's been mostly sitting for the last 10 years.

When it does, it's not seized, but no ignition and the starter won't engage either. I find that part to be a little confusing as the starter isn't tied to anything, as far as I can tell. Just a starter relay and the starter itself.

 

[racerone]

Please be clear.---Are you sure the water tube is in a rubber grommet at both ends ?------Was the water tube installed in the upper grommet first ?

 

[Crosbyman]

no ignition and the starter won't engage either..???

to many rabbits here ....better find out this one before going down a wrong hole

 

[SpoonyWacker]

Please be clear.---Are you sure the water tube is in a rubber grommet at both ends ?------Was the water tube installed in the upper grommet first ?

I replaced the lower grommet (it was a mess). I did not replace the upper grommet, but installed the tube in the upper grommet first. See the attached video of the water coming out. Does that look like it's working right? Is there a better way to validate water is making it through the block?

 

[racerone]

Looks to me that the water pump is working fine.

 

[oldboat1]

Plenty of water. Old coils or condensers may be heating up -- pull the flywheel and replace (cracked coils are a sure sign they need replacing).

Sandpaper the battery connections, and be sure the connections are tight.

 

[Crosbyman]

when the starter does not turn do you hear the selenoid clicks ???

has suggested repolish al connections....starter may have a bad spot

if the selenoid clicks when the key is ON.... just tap the starter with a rubber mallet see what happens ....

 

[Sea Rider]

Fresh or salt water use, with low or high run hours ? Being a 61 year oldie any electrical component could be failing during operation, heats up, shorts, turns motor OFF to work again once cold and miss again and again. The issue is which one it's the culprit ? Electrical components with erratic behaviours are the worst to troubleshoot fast.

Happy Boating​

 

[oldboat1]

Get an open air spark tester (not the in-line enclosed style). Pull the plugs to reduce compression, and test by pulling it over with the rope starter.