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1968 Evinrude 55 HP 55873

N

Norm Magnuson

Contributing Member
Motor has overheated a couple of times. The external water tube (# 314489) melted and the part slid down into the water intake and caused a 85 % reduction of water flow. Do I need this ext. water tube or will the motor pull cooling water up without it?
Thanks,
Norm
 
Yes you need that tube.----Available new on this site.-----Do a compression test before you spend any beer tokens on this motor.-----Does it still use the hot light or have you installed a horn ?
 
racerone said:
Yes you need that tube.----Available new on this site.-----Do a compression test before you spend any beer tokens on this motor.-----Does it still use the hot light or have you installed a horn ?
Click to expand...


Will purchase new tube and replacing all rubber gaskets and o-rings around the impeller in case they also suffered heat damage. What should my compression be in each cylinder? I have a hot light and it still works!

Thanks for your response.
 
Remove 3 sparkplugs.----Ground the sparkplugs.----Or crank with a remote switch on solenoid.-----Install tester.----Crank till needle stops going up.-----Some will argue.-----But there is no need to open the throttle.
 
Racerone,
completed compression test.
cylinder #1. 125. 130
cylinder #2. 120. 125
cylinder #3. 130. 130

test was run cold without the lower gear case as I’m repairing impeller, pick up tube and other rubber seals and gaskets. I ran 2 tests for each cylinder. Last fall it ran like I remember it as a kid. Not at 60 psi as you had stated, but is 160 psi what it supposed to be when new. I’ve found over sized rings but no luck on over sized pistons. I’m assuming I would need a new crankshaft as well. Is there a kit available with pistons, rings and gaskets etc. that you know of?
Thanks,
Norm
 
Well---140 + PSI is what I would want to see !!----Why would you assume a new crankshaft?----If in Canada---evinrudeparts.ca-----Might help find parts.
 
I’m close but not quite there. Not sure if possible to just install oversized rings but if you go this far you might as well complete a rebuild. It seems to burn more fuel than I can remember. I live in TN but I did check out the Canada sells and they did have all the parts. Next week I’ll have the parts for cooling the engine and will see how it runs. What are your thoughts?
 
My thoughts: It would be a stroke of luck if that motor is not destroyed by such overheating. Those motors do not like to be ran hot.
 
Racerone, I have all the new parts in the gear case replaced and mated to the motor. I’m trying to come up with a water test container/tank. Found a tub that’s long enough but I only have 16” of height. This will bring to the top of the motor from the skeg to the gear case oil fill screw. Will this be deep enough to run the motor? I will keep the hose running into the container at all time. If not, how far up from the skeg do I need to go?
Thanks,
Norm
 
Racerone, ok I have the motor in a container with water filled to the bottom of the lower mounts. Stills runs hot but was shutdown quickly. Took thermostat out and both inlet and outlet was bone dry. I installed a new thermostat last February and last Friday I installed a new impeller, 2 new rubber grommets, new ext water tube, new key from shaft to impeller, new impeller housing seal, new water tube impeller grommet. The 2 copper tubes are seated in the impeller correctly. Before I installed the lower gear case, I spun the shaft and the impeller worked freely. The shaft must be connected to the motor as you spin the fly wheel by hand the propeller spins. Any ideas before I remove the motor and work through the exhaust? I use all oem parts. I’m lost.
 
I also used my air compressor on both inlet and outlet of the thermostat and I had air passing through all exhaust ports. The motor starts and runs fine except for the cooling side. It has to be something small I’ve overlooked.
 
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