Motor has been sitting for 3 years.

I recently bought a boat from a friend that has been sitting for over 3 years. I did most of the maintenance on it before that, so I feel confident the engine is in good shape. I've been told to add a small amount of power transmission fluid to each cylinder and let it sit for a while before trying to start. They said this will also de-carbon the engine once it gets running. It's an '84 120 mercruiser. Any thoughts on this one?

Re: Motor has been sitting for 3 years.

I just did the same on my father's boat that was sitting. I connected a remote tank because I did not trust the gas that was in the tank. I also pulled the distributor and operated the oil pump with a drill to get oil flowing through the engine before I cranked it over.

Re: Motor has been sitting for 3 years.

bruceb58 said:

I just did the same on my father's boat that was sitting. I connected a remote tank because I did not trust the gas that was in the tank. I also pulled the distributor and operated the oil pump with a drill to get oil flowing through the engine before I cranked it over.

Click to expand...

What he said, & I think I would squirt plain oil in the cylinders.....

Re: Motor has been sitting for 3 years.

Thanks for the replys. I like the suggestion about the oil pump. can't hurt for sure. I drained the old gas out, so at least that's good.

Re: Motor has been sitting for 3 years.

Pull the oil pan drain plug first to check for moisture. Dosent take much to mimic another "water in oil " thread.Couldnt hurt to drain whats in there and refill it.

Re: Motor has been sitting for 3 years.

that little trick bruce mentioned about spinning the oil pump with a drill.
is a good one....ive done it several times on car motors ive revived.

i dont know if it did any good....but they sure didnt sound dry when i spun them over !!!!! in all cases... the engine worked for years after!

cheers
oops

Re: Motor has been sitting for 3 years.

priming the oil pump is a necessity. get it greased up.

Re: Motor has been sitting for 3 years.

oops! said:

that little trick bruce mentioned about spinning the oil pump with a drill.
is a good one....ive done it several times on car motors ive revived.

i dont know if it did any good....but they sure didnt sound dry when i spun them over !!!!! in all cases... the engine worked for years after!

cheers
oops

Click to expand...

The main thing it does is putting oil into the rod, main, and cam bearings. They are real dry after 3 years.

Re: Motor has been sitting for 3 years.

I will head this advise for sure. Its a good motor, so its worth doing right.

Re: Motor has been sitting for 3 years.

Bt Doctur said:

Dosent take much to mimic another "water in oil " thread.

Click to expand...

Perish the thought that something like that might happen.

Re: Motor has been sitting for 3 years.

If your going to put any oils in the cylinders to sit i suggest ( MARVEL MYSTERY OIL) it's marvelous.

Re: Motor has been sitting for 3 years.

I am doing a similar exercise with my 350. I am so not mechanical I have to ask a couple of real dumb questions. I suppose to get the the Marvel in the cylinders, you pour it in the plug holes.

If so, 2 questions:

1) How do you get it in there, as it is difficult to use a funnel.

2) How much would you put in?

Re: Motor has been sitting for 3 years.

try a squirt bottle, or an oil can. Wouldn't think it takes much. one good squirt should do it.

Re: Motor has been sitting for 3 years.

I would just give it a few good blasts of WD40 into the cylinders. After you have ran the oil pump for about 30 seconds, turn the engine over without the plugs a few times. Changing the oil before starting is also a good idea. Replace the plugs and fire it up.

Have a great day,

Rob.

Re: Motor has been sitting for 3 years.

Robj said:

I would just give it a few good blasts of WD40 into the cylinders. After you have ran the oil pump for about 30 seconds, turn the engine over without the plugs a few times. Changing the oil before starting is also a good idea. Replace the plugs and fire it up.

Have a great day,

Rob.

Click to expand...

WD40 is not a good lubricant. In fact if anything, it might do more harm than good.

Re: Motor has been sitting for 3 years.

bruceb58 said:

WD40 is not a good lubricant. In fact if anything, it might do more harm than good.

Click to expand...

Yup!........

Re: Motor has been sitting for 3 years.

My grandfather, who was a mechanic, swore by marvels.

Re: Motor has been sitting for 3 years.

I agree with Haut no WD40....Definately Marvel Mystery Oil.....I found a little (1/2 pint) squirt oil can at the hardware store, fitted it with a flexible small diameter pvc hose and squirt the oil inside the cylinders. The flexible hose allows you to get down inside the cylinders.

Re: Motor has been sitting for 3 years.

bruceb58 said:

WD40 is not a good lubricant. In fact if anything, it might do more harm than good.

Click to expand...

You are correct it isn't a great lubricant, BUT the idea isn't for it to lubricate as much as it is to try to release the rings from the cylinder walls so they don't break.

Several of these ideas are good. My suggestions are as follows.

1. don't rush this process a day extra of sitting during it will only help not hurt.

2. pull spark plugs

3. take squirt can and squirt automatic transmission oil into cylinders, you can't use too much but you really don't need much either. Too much will just make a mess but that is the worst it will do. The idea of Autotrans (any auto trans fluid will do, Dextron II is likely you least expensive option) fluid is it is very high in detergant and is fantastic for unseizing metal components. Let it soak for a day at least, again longer is better.

4. take a johnson bar (swing bar) and put a socket on the crankshaft pulley bolt. Slowly move it back and forth not moving much in either direction. Idea here is to unseat rings from cylinder walls and move any debris from soaking on cylinder walls. Once you find it moves easily you can rotate the crankshaft a couple times around.

5. again shoot some trans fluid into cylinders let soak for a day, more if you wish

6. drain engine oil from oil pan and pour in new oil and change filter

7. pull distributor if you wish and prime oil system, this is an ideal step but if you wish can be stepped over.

8. with engine full of new oil and spark plugs still out crank engine over (rec disable ignition system so stray sparks don't give you a zap or ignite anything)
Recommend laying blanket over spark plug holes or rags to collect oil that will come out.

BE SURE TO STAY OUT OF LINE OF FIRE OF SPARK PLUG HOLES !!!! Trans fluid will be shooting out!!!!!



6. Once engine cranks over nicely 10 cranks/pumps you should repeat this step 2 or 3 times. No load is on rings or bearings and oil pressure has a chance to pump up a bit.

7. Now install new spark plugs and fire it up. Might smoke abit due to oil in cylinders but will cause no problems.

After running for 10 minutes making sure no abnormal noises, temp etc.... you can do a final step if you like and remove spark plugs and do a compression test to verify.

Hope his helps.

Re: Motor has been sitting for 3 years.

My idea with the WD40 was it is thin and will go into areas that plain oil will not. I have also heard of diesel fuel also being used for this. Same idea, try to free up the rings with a thin lubricant. Once things are moving then squirt the heavier oil into the cylinder. I have used WD40 for this many times and has worked for me. While I agree it may not be the best lubricant, I think it is good for this application.

Have a great day,

Rob.