Been sitting for a while! 1978 Johnson 115HP V-4

[chrisjt]

I just picked up a 1978 Johnson Sea-Horse V-4. Model# 115ETL78C. I took plugs out to inspect and than (SEE Pictures) I removed the heads. There is surface rust on the cylinder wall of one cylinder the others are pretty clean, I sprayed a lite amount of WD-40 in to cylinders to help free up. How do I remove the surface rust? I would like to run water thru the motor to clean it out and be sure there are no obstructions with water flow, How can I do this? I don't think it is seized but the fly wheel does not turn, I did not try to force the flywheel to avoid damage, What should I do to free up fly wheel?

 

[TD_Maker]

We....it does not look good. What makes you think its not locked up? If the flywheel does not turn...then its locked up...at least temporarily. I would spray each cylinder with Kerosene and let it sit for awhile. See if you can break it free. If so, then you can put the heads back on and see if it cranks. Everything starts with a compression test.

However,

Don't forget about the lower unit. A broken lower unit will keep a powerhead from turning as well.

 

[emdsapmgr]

Bombardier's EngineTuner is another solvent which may help free up the pistons. It comes in an aerosol spray. Not just sure what is going on with picture #2. The piston is not recognizable. What is the story. Did some mouse build a home inside the cylinder? TD has a good suggestion. Pull the lower unit off then try to rotate the flywheel by hand. I am sure you will be wanting to replace the lower unit impeller prior to running it, so the lower unit has to come off any way. (just don't spend any $ on it till you know what is going on with the powerhead and it's compression.) You can also pull the 4 bypass covers off the side of the block and inject the solvent direct to the pistons, cyls. When looking at the sides of the pistons, be sure the top piston rings are all intact.

 

[chrisjt]

It was a surprise to me when I pulled heads. Yes it was a nest of some small critter. I'll add solvents to cylinder heads and pull lower unit and replace impeller and/or water pump assembly. To free up flywheel should i do this by literally grabbing it with my hands or is there another way.

 

[racerone]

A socket ( 1-5/16" ) on the flywheel nut and work it back and forth.

 

[chrisjt]

Thanks racer, I'm not as strong as I used to be and my sons 1 at 19 other 25 are to busy with girls and family. There great kids so its all good!!!

 

[jakedaawg]

As far as the engine not turning over...pull lower unit and try. You should be a ble to spin by hand with battery disconnected and key switch in the off position.

To free up stuck rings and such...transmission fluid seems to work the best for me, I also have had good luck with Marvel Mystery Oil. The engine tuners available require the engine to be running as far as I know.

Obviously the nest needs to be clean out, but unless the plugs were out while it sat the critters got in either through the exhaust or carbs. Probably exhaust as there are reed valves in the way behind the carbs. I would consider pulling exhaust cover if it was stored with the plugs in.

There is a wrench available for turning the flywheel. It engages the teeth on the flywheel.

 

[emdsapmgr]

The Bombardier Engine Tuner works when applied topically (can be applied directly.) Usually when using it, you can't spray it directly on anything, so you wind up letting the engine ingest it while running. (you can spray it in the spark plug holes)

 

[chrisjt]

Thank you all. With the advice from all of you flywheel turns. NO PROBLEM.