super seahorse 40hp issues

[redwind]

Hey guys,
I have a 40hp johnson super seahorse (rdsl-23) and Ive had it running almost perfect.
Ive put new coils in and tinkered around with almost everything (rebuilt carb, fuel pump and what not)

So fast forward to yesterday...
Had it running pretty solid for about an hour (in garbage can) and when I put the throttle to idle it would slowly drop down to the point in which it would kill itself. So okay the low speed needs some fine tuning which wasnt a big deal.

After it had stalled itself I figured why not put the generator back on and see it that is working as well in the next run.
put the genny back on and went to start and have no fire. engine cranks and cranks but nothing.

Ive checked the fuel pump (pulled off line from tank to pump no blockage, pulled of line from fuel pump to carb and it shoots fuel 10 ft, on choke you can tell the carb is pulling fuel from the bowl and checked for fuel in the cylinders and they do (took a lighter and they both light up like a rocket))
SO... That tells me the fuel system is working correctly which now leads me to check for spark.
Go to check for spark and have nothing...which does not make any sense as I had it running almost mint before.

anyone have anything they think I should check????

 

[Crosbyman]

sounds like the magneto is shut down ( points grounded or shorted ...I don't have a parts layout ... maybe a defective kill button, switch whatever... ties in to the points to kill it

in any event you gotta get the sparks back .... if not an external issue you will need to pull the flywheel for a peek


ok found it... 1961 rdsl23 lots of electricals and a safety cut-out switch to go bad

 

[redwind]

I have the flywheel off right now (were both thinking alike haha)
Points look perfect and nothing looks out of the ordinary.

Side note though, I did splice the wiring into a 1990's throttle control unit, I did move the harness go gain access to the power points on the fuse box. Id really hate to tear open the harness again to see if that where my short is (soldered and heat shrunk everything)

 

[redwind]

ok found it... 1961 rdsl23 lots of electricals and a safety cut-out switch to go bad

I have the neutral cutout disconnected, only cut out left is the vacuum which I would think is rare to go bad as its a big spring inside according to my research

 

[Crosbyman]

I don't work those big engines but the magneto is the same basically can you disconnect any extra wire to the points
and see if you have sparks ...remove plugs and ground them with fat alligator clips

no need to fire it up just check for sparks

I have a feeling something is shorting or grounding the points

 

[jimmbo]

Disconnect any modifications you made to the wiring(you said you spliced in a 90s control box). and see if it runs. what wires did you mess with or disturb when you installed the generator?

 

[F_R]

There are two black wires coming from the magneto. Disconnect both of them and if you now have spark you know the problem is external.

It's hard to believe the generator has anything to do with it, unless there is a wiring error.

 

[redwind]

Disconnect any modifications you made to the wiring(you said you spliced in a 90s control box). and see if it runs. what wires did you mess with or disturb when you installed the generator?

thats the thing... I didnt change anything other than putting the pully on and belt..
only thing I can think of is the harness when I pulled the fuse box out to check for power at the power zone from the generator..
Ill cut the harness open tomorrow if it ever stops raining (we needed it though river levels have dropped 5+ feet)

 

[redwind]

Okay finally rebuilt the harness from scratch and had some time to tinker around.

So so here my newest issue which was probably the original issue...and I found this by fluke...
while trying to adjust my throttle linkage I ended up getting shocked with one hand on the gear lever on the right side of the motor and my other hand touching the linkage on the left side.

Pulled off the top cyl plug wire and no change in idle, put back on, pulled bottom plug wire and died.
This tells me the top cyl is arching out some where which is why I got shocked.
I have new coils installed and checked both plug wires but they seem fine.

Anyone give me some pointers?

 

[Chris1956]

Did the flywheel rub the top cylinder spark plug wire?

 

[redwind]

Nope no rub marks any where.
Bit of an update though. Found out the coil was grounding out in the control box and in turn the spark was arching through the plastic in the throttle control cable at the end of the linkage. Well fixed that and........



still till don’t have spark on cyl 1.
Thought by chance they might of sold me a dead coil last year so I swapped the coils around to the same result.
Could this be a timing issue?

 

[oldboat1]

Go back in and clean/reset the points (may be able to do both from the observation hole under the cover on the flywheel.)

 

[redwind]

Go back in and clean/reset the points (may be able to do both from the observation hole under the cover on the flywheel.)

yep went back and set them again and low an behold i have spark on number one, but the plug boot was ripped on cyl 2 so i just went and bought new wires and boots today and replaced it all.

thing runs mint now starts easy too!
only issue im having now is when i have the hood off I can rev through the range pretty fine (minor fine tuning needed) but the moment i put the hood back on itll rev up for about 10 seconds and then it sounds like its starving for air. Kinda like a clogged air filter on a car.

 

[racerone]

So the motor is 57 years old.-----There is no issue with the design of the hood.-----Running in a barrel it would be trying to pull exhaust air in or you have an internal exhaust leak !!----Put it on a boat and test run on the river or lake.

 

[redwind]

so needless to say.. i ended up breaking my femur and had some time to tool around.. adjusted throttle linkage and got the idle up a bit. took the motor out of the barrel and put some muffs on. thing sounds almost mint. hopefully will fire up nice next year and ill get the little bastard in the water.