Merc 800 EL Stuck Engine

[bill-austin]

Hello Everyone,
A friend of mine gave me a Merc 800 EL from 1960 last week. He told me that he had had the motor for a very long time, but had not used it in over 30 years. After getting the motor home and removing the cowling and cover, I removed the spark plugs and sprayed Kroil into each cylinder. The engine is obviously stuck. I would like to hear from anyone else on AOMCI who has dealt with a stuck outboard. It’s a 57 year old outboard motor that does not show any signs of abuse, other than not adding corrosion preventative to the cylinders before storage. Any thoughts or recommendations would be appreciated.
Regards,
Bill Austin
Saint Marys, GA

Mercury KG7, KH7, Mark 30, Merc 800

[outbdnut2]

First, determine if the powerhead is stuck, or is it the lower gears rusted up? or I have also had water pump impellers with broken vanes stick the motor. If you can wiggle the flywheel back and forth at all, (often when a motor is totally stuck trying to turn it over with rope or electric, you can still wiggle the flywheel back and forth a tiny bit with your hands or with a wrench on the flywheel nut), stick a long screwdriver in the spark plug holes while you wiggle the flywheel back and forth and you can feel if the piston is moving slightly with it. This method has helped me determine which piston or pistons are stuck on several motors. The Kroil you are using is good stuff – if you can, position the motor with cylinder heads up so the kroil runs down on the rings and stays there.
Good Luck!
Dave

[mercuryspecialist]

I would echo Dave’s advice. I did send you a private message also.

Regards,
Joe

[jeff-register]

Lay it on it’s forward side & spray into the cylinders & let soak. Usually what kills these motors would be a dirty fuel system, run them lean & score a piston & cylinder. Merc isn’t known for great fuel pumps. I would pull the crankcase as it needs new seals & bearings on the crank, then you can look for score marks in the cylinders without the strong-arm method. if you get it free check compression on them, should be 120 at the lowest & all within 10% of each other. They often blow the block to crankcase seal cause not using a torque wrench. They are a hi performance motor & everything with the timing & carbs synced to get them to run. Run your idle jets a little rich to avoid the bog. If you get one you can take apart without breaking at least a few studs, it’s a good day. They leak water from the exhaust covers on the block to rust things too.

[jeff-register]

Hey Joe!!
Good to see your post, I’ll call you beginning of the week 😀
Jeff

[bill-austin]

Thanks for the advice Dave and Jeff. I removed the lower unit this afternoon and it was free and turned over easily. There was not any water in the lower unit gear case. I’ve got Kroil soaking in the cylinders and I fully suspect that I will just have to be patient and let the Kroil do it’s job.

One more question. Does anyone know the part number for the ignition switch. I’ve got all of the controls for the motor, but the key was missing for the ignition switch.

Thanks,
Bill Austin

[outbdnut2]

I believe 1960 was a "Dockbuster" year with no gearshift, but has the reversing powerhead, where you turn the key the opposite way and the starter spins and starts the motor in the reverse rotation direction. That ignition switch is unique to the non-gearshift models. I don’t know what the part number is. If all else fails, try http://www.twincityoutboard.com go to the website and look up the phone number and call them – they are an outboard junkyard and will mail them. I’d try posting a free "Wanted" ad on the classified board here first – you will likely find one cheaper. Someone here may have a key that fits too if there is a number on the keyhole.
Dave

[eviltwin]

quote Bill Austin:

I removed the lower unit this afternoon and it was free and turned over easily. There was not any water in the lower unit gear case. I’ve got Kroil soaking in the cylinders and I fully suspect that I will just have to be patient and let the Kroil do it’s job.

What they were saying is if the motor turns with the lower unit removed the pistons are not stuck. Kroil is not the solution for this case. Sounds like something in the lower unit is stuck.

[outbdnut2]

quote EvilTwin:

quote Bill Austin:

I removed the lower unit this afternoon and it was free and turned over easily. There was not any water in the lower unit gear case. I’ve got Kroil soaking in the cylinders and I fully suspect that I will just have to be patient and let the Kroil do it’s job.

What they were saying is if the motor turns with the lower unit removed the pistons are not stuck. Kroil is not the solution for this case. Sounds like something in the lower unit is stuck.

I took this to mean the lower unit was free, not the powerhead – like you can spin the propshaft turns over in neutral. Bill – please clarify.

[outbdnut2]

quote outbdnut2:

quote EvilTwin:

quote Bill Austin:

I removed the lower unit this afternoon and it was free and turned over easily. There was not any water in the lower unit gear case. I’ve got Kroil soaking in the cylinders and I fully suspect that I will just have to be patient and let the Kroil do it’s job.

What they were saying is if the motor turns with the lower unit removed the pistons are not stuck. Kroil is not the solution for this case. Sounds like something in the lower unit is stuck.

I took this to mean the lower unit was free, not the powerhead – like you can spin the driveshaft once it was pulled with the lower. Bill – please clarify.

[Author]

Posts