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1988 Johnson Spl Help

M

Madboater

New member
I’m looking for some guidance on what to do with the engine listed in the title. It is a 48hp with two cylinders.
So I finally got the motor running smooth after dual carb rebuilds and a new battery. Took it out on the lake and it was running great for about 5 minutes.
Then the buzzer warning started going off from the shifter box. There are no indicators to clarify what this noise means but in the manual it says it’s an Overheat alarm. It was constant not intermittent.
Well...about 10 seconds later I heard a gear grinding noise and lost drive to the prop. Yes, I turned it off then.
Out of curiosity, about 10 minutes later I turned the engine on and the alarm was gone and the prop would engage slightly. I didn’t go full throttle but it was definitely turning but still with a grinding noise. Turned it off very quickly.
Does anyone know if these are separate issues or not?
Any guidance would be appreciated. I’m trying to fix this thing up for an older friend that just wants to go out on the lake a few more times before he is fishing from the clouds.
Thanks.
 
Yap two issues but both will be in lower unit. water pump and gears. These older motors only had 1 alarm, over heat. after rebuild, first start up monitor temp closely, thermostat maybe stuck closed and need to be changed.
 
Thank you for your help. I drained the oil...it looked like Tinkerbell scattered magic glitter into the oil. Not good I know. Dropped the lower unit and will be replacing gears and bearings and seals.
Guess it can’t hurt to replace the thermostat too.
 
just a quick note, the bottom two bolts on the cyl. head cover are very hard(PITA) to get too. but removing the whole head is way easier(But if lots of corrosion, breaking bolts maybe an issue), a compress test may also help to decide, if low a new head gasket can't hurt, should be around 140. you say you want to get out with older friend so this maybe side tracking that goal.
was the water pump impeller in one piece?
 
Thanks Scalhoun.
I don't think a head gasket is the issue at this point. Can't hurt to have a new one after seven years of sitting though. Thanks for the tips.
Water pump was in one piece and still in good condition but due to the fact that I don't want to go through taking this thing apart again, I'm getting a new one.

Just a few notes to help anyone dealing with the same problems on this engine.

By the way, to anyone that has to take the lower unit of one of these things. Just unscrew the screw on the part that attaches directly to the shifter arm. You don't need to pull the cotter pins on the other side.
Also, a stuck drain plug was easily remedied by buying a 20 dollar impact screwdriver that you hit with a hammer from Advanced Auto Parts.
I would also invest in some nut drivers with sizes around 15/16 and larger. It will save you time on the carb cover and carb plate.
the carbs are connected with a small metal arm that inserts into plastic fittings. You don't have to undo any adjustment screws to separate them. Simply pull or push(carefully) the arm out of the fitting. I kept it attached to the one that I was not working on so as not to confuse how it would go back.
One more thing. Spend the couple bucks to get a magnet tool with a small magnet that extends to at least 12 inches. Unless you have magnetic fingers, you will most likely drop a screw or two into the abyss at the bottom of the engine case.

That's all for now.​
 
Much easier to just remove the hitch pin and push the shift arm over.-----Almost no tools required.----It can not be made any simpler.
 
Could do that too I guess. Anyway, now that the lower unit has been taken apart, I see that Johnson must have put some extra chunks of metal in there in case I needed to weld them to broken parts to fix them. How thoughtful.
So...anyone have some gear sets for cheap?
 
No gear sets are not cheap.-----The procedure I posted with the hitch pin was for V-4 motors, sorry bout that mistake.
 
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