Merc 115 "frozen up" help!!!!

[boydog]

I purchased a 1981 Checkmate Predictor ski boat with a early to mid 80's Mercury 115 (blue cowling)<br />Thank goodness I didnt spend my life savings on it ($500.00) because the motor will not turn over - tried to spin the flywheel and little to no play at all and it is definitely in neutral.<br />the decals state the last time it was in the water was 5 years ago -I filled each cylinder with liquid wrench and outboard oil and tilted it back up so it would "soak" in<br />any other suggestions? can I put a wrench on the flywheel nut and try to turn it back and forth real easy??<br />thanks

 

[SeaKaye12]

Re: Merc 115 "frozen up" help!!!!

Hi Boydog...Cute Nick!<br /><br />Hmmm...sounds like you're approaching the matter like I would... don't know if that's entirely a good thing <br /><br />There are a lot of in-line wrenches on this board...Clams_Canino is one of them who rebuilds "Tower of Power" powerheads...<br /><br />What's the motor's history? Was it damaged at some point; or maybe you don't really know?<br /><br />Post the serial # here..at least you can find out the year....helps when ordering parts too... <br /><br />I think I remember Clams saying that your vintage in-line was the "cream of the crop" though...so hopefully you can revive it and have some fun.<br /><br />Thanks for reading, Chuck

 

[Chris1956]

Re: Merc 115 "frozen up" help!!!!

Boydog, You may want to remove the lower unit, to assure that it is not seized. At least change the gear oil at this point, and inspect the old gear lube for water.<br /><br />It doesn't take much rust to seize a ring to the cylinder wall, although in my limited experience, this only occurs when cooling water finds its way into the cylinder through some defect in the water jacket covers.<br />If the oil soak doesn't work, the best bet is to disassemble the powerhead to spot the exact problem. If the rust is severe, you may need to bore the affected cylinder(s) and install new pistons and rings.

 

[Silvertip]

Re: Merc 115 "frozen up" help!!!!

It takes patience to unsieze and engine but it can be worth the effort. If you filled the cylinders with Liquid Wrench, just let it sit for a week or more. Then using a wrench, GENTLY try to rotate the engine just a little bit. You are only looking for movement, not total rotation. If (or when) you get movement, rotate the engine back & forth, again very gently, until it tends to stop. Repeat the motion within the movement limits several times. Reload the cylinders with liquid wrench and let it sit some more. Repeat the process until the engine can be rotated full circle. Never attempt to force it as you will break rings, ring lands, or cause cylinder scoring by dragging deposits up and down the cylinders. Once you get it free, load the cylinders with oil and rotate it. When totally free, with plugs removed, spin it with the starter to expel everything. Using fresh fuel, see if it will start.

 

[boydog]

Re: Merc 115 "frozen up" help!!!!

thanks for all your help guys!!! it appears that the key is to not be in a hurry and let the cylinders soak - I was also told to fill the cylinders with marvel mystery oil - which I will do also<br />once again thanks!!!<br />will keep you informed as top its progress

 

[emckelvy]

Re: Merc 115 "frozen up" help!!!!

Pull one or several of the intake port covers (on the same side as the fuel pump) and you'll soon see if it's corroded badly internally. You can also get more lubricants into the 'guts' via the intake ports.<br /><br />The tip to pull the lower unit is a good one, you want to confirm or deny it as the problem. Actually, it'd be a lot better if it were frozen and the powerhead was good!<br /><br />You can use a 1/2" breaker bar and 15/16" socket on the flywheel. If it won't break loose with that, there's definitely problems somewhere.<br /><br />HTH and G'luck with the motor.........ed

 

[Silvertip]

Re: Merc 115 "frozen up" help!!!!

Marvel Mystery oil is very good for this purpose. But use a breaker bar very carefully. No sense getting the engine loose only to have damaged things.

 

[boydog]

Re: Merc 115 "frozen up" help!!!!

UPDATE - pulled the lower unit and it is the culprit!!!! the power head moves freely now as ity should and the lower unit is the one "locked up"<br />tell me guys what am i looking at as far as a repair bill?? i know it is dependent on what is wrong - but worse case scenario??<br />thanks

 

[ricksrster]

Re: Merc 115 "frozen up" help!!!!

Lower units show up on Ebay all the time. Check it out from time to time.

 

[boydog]

Re: Merc 115 "frozen up" help!!!!

just found one on ebay for 375.00?? good price on a used lower unit?<br />what about looking at getting this one repaired?<br />thanks

 

[rodbolt]

Re: Merc 115 "frozen up" help!!!!

I may can go ya one better<br /> shoot me a mail at rodbolt40 at yahoo