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2hp Seahorse barely runs

S

seahorseshoes

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2hp Johnson Seahorse 1982

I bought a motor that I knew wasn't running great. From it's condition it looks like I'm not the first person who's attempted to get this thing to run right. Everything seems clean and in good condition.

Motor runs badly and at only one setting. Won't idle, won't run fast.
Only runs when throttle set a bit faster than the start position.

Ignition
Looked in very good condition. Set at .020.
New spark plug, gapped.

Reed Valves
Good condition. Fully closed and open just fine.

Fuel
Gas tank clean. New fuel. Clean see-thru inline filter.

Carb
Spotless. I even pulled out the expansion plug.
All tiny passages are clean and open.

Cylinder
Didn't visually inspect but compression is 90psi

Carb adjust
I did the one full turn out and 1 1/2 turns out.
Made sure (gently) to ensure the screws were fully seated before turning open.
Needle/screws looked to be in good condition.

Fine tuning of carb
I know the instructions for tuning say: (High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to full throttle. In segments of 1/8 turn, waiting for the engine to respond between turns, start turning in the bottom high speed needle valve.

I attempted this but it doesn't seem to help. Everything seems to result in stalling.


I'm stumped. Advice appreciated.
 
I should add:

Black oil in water

For the brief times that I've had this motor running in a small barrel there's been black oil residue in the water. I'd just assumed that this was a separate issue with a bad seal in the leg. Although possibly this might be a sympton of a bad crank seal. But would a bad crank seal(s) really cause a motor to run this badly?
 
Oil in barrel is normal. It is the oil that you put in the gas. It has gone through the engine and done it's job, then out the exhaust. Something else is responsible for the bad running. But excess ​oil in the water may be a by-product of bad running
 
1982 2hp Johnson.... Start trouble-shooting from Scratch:
90 psi compression?? Unheard of... Double check that!
Use a Champion J6C Spark Plug gaped at .030
Fuel mixture = 50/1... 1 pint of good quality 50/1 oil to 6gal of 87 octane gasoline.
********************
Remove flywheel...
********************
Check the coil alignment:
(Magneto & Driver Coil Alignment)
(J. Reeves)

To align the coils properly, have the metal vertical portion of the coil yokes aligned with the inside edge of the bevel that exists on the top portion of the aluminum seat upon which the coils sit. This creates the proper distance between the coils and the flywheel magnets. Faulty alignment creates friction and the yokes of the coils heat up, turn blue and expand.
********************
Check the continuity of the coil as follows.
(Regular Magneto Coils - Continuity Test)
(J. Reeves)

Checking the continuity of the ignition coils....... Have the ohm meter set to High Ohms.

Remove the primary wire from points. Remove the coil ground wire. You do not want either of these wires touching anything.
Connect the black lead of a ohm meter to the spark plug boot terminal, then with the red ohm meter lead, touch the ground wire of the coil.

Then touch (still with the red lead) the primary wire. You should get a reading on both touches (contacts). If not, check the spring terminal inside the rubber boots of the spark plug wire.

If there is no continuity between the secondary circuit (spark plug) wire and the primary or ground, remove the coil from the armature plate, then check the continuity directly between the prong within the coil (prong that the plug wire connects to) and the primary and ground. Poor or no continuity of a coil (or plug wire) is one reason for weak spark, s/plug fouling, or no spark.
********************
Check the spark:

Using a test whereas you can set a "Air Gap" of 1/4" (available at auto part stores)... the spark should jump that 1/4" air gap with a strong blue lightning like flame... a real SNAP!
********************
Setting the points:

Have the flywheel key aligned with the fiber rubbing portion of the points... Set the points so that a .020 gauge will slide thru but a .022 will not.
********************
Make sure that fuel flows from tank to the carburetor freely (prone to clogged fuel filter in tank).
********************
(Carburetor Adjustments - Two Adjustable N/Vs)
(J. Reeves)

Initial settings are: Bottom high speed = seat gently, then open 1 turn out. Top slow speed = seat gently, then open 1-1/2 turns.

Setting the high and low needle valves properly:

NOTE: For engines that DO NOT have a shift selection, obviously there is no NEUTRAL position. Simply lower the rpms to the lowest setting to obtain the low speed needle valve adjustment.

(High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to full throttle. In segments of 1/8 turn, waiting for the engine to respond between turns, start turning in the bottom high speed needle valve. You'll reach a point whereas the engine will either start to die out or spit back (sounds like a mild backfire). At that point, back out the needle valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest setting.

(Low Speed) Slow the engine down to where it just stays running. Shift into neutral. Again in segments of 1/8 turns, start to turn the top needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. Eventually you'll hit the point where the engine wants to die out or it will spit back. Again, at that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustments, you will have no reason `to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
********************
Starting Procedure:

Tank valve open.... Throttle cracked so as to open throttle butterfly somewhat.... Choke pulled out to close butterfly.

When engine fires/starts, push choke lever in to have butterfly horizontal (open).
********************

That should do it!
 
Thanks for the responses.

Just to clarify, the oil in the water isn’t two stroke oil, it’s definitely gear oil from the leg (black instead of rainbow).

Running 50:1

I’ll see what a multimeter tells me about the coil etc and post an update
 
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