old seized motor

[Cut n' Jump]

Me and a friend just went halves on a boat with a '78 Evinrude 70 horse. We finally got it freed up after lots of oil and removing the lower unit. The cylinders appear to have rust coming out of them. We've cleaned the carbs and when cranking w/o plugs a mist of fuel sprays out. This blows out what looks like fine rust or mud. I fear its been overheated since the water pump seems locked up. [havent got that far yet] The top cyl. reads 85psi the middle 120 and bottom 140. I think the filth may be messin up the ring seal. No knocks and the pistons dont rock like they're loose either. Someone put a new coil on the top cyl. at one time.Anyone here know how to clean this motor out better than running fuel through it?

 

[mrm]

Re: old seized motor

TRY SHOOTING some marvel mystery oil into each cylinder.<br /><br /> Good Luck

 

[Fouled Plug]

Re: old seized motor

Compression numbers are good if you can get #1 to come up. I'd soak the rings in WD-40, and let it sit, cranking from time to time for a few days. Hopefully you're into this motor cheap, and can fire it up to see what happens. I've brought back some real lumps and I hope you guys can too. Good luck!

 

[Cut n' Jump]

Re: old seized motor

We finally got it freed up after lots of oil [in the cylinders and we dumped in fuel too.] What I'm talking about is a way to get all that stuff out before firing it up. I thought about using some carb spray and cranking it after that. Or maybe just a gallon of solvent [mineral spirits]. What I'm afraid of is gunk washing back into the crankcase. Then again the crankcase might be where this stuff is coming from. Maybe a mud daubers nest was in an exhaust port or something. All I know is I'm not starting it until the rusty looking stuff ain't coming outta the holes no more. Maybe I'll drown the crankcase with carb spray or solvent and crank it at the same time. Would that be a bad idea? I refuse to spend any real money on this motor. I hope its just sticky rings making low compression.

 

[Cut n' Jump]

Re: old seized motor

Its real cheap $125 apiece. 17 foot Phantom tri-hull and a big wide dilly trailer that actually fits something other than a jonboat.<br />Its really just a dumb idea that we could make a few bucks by getting it running. My friend started off wanting to buy it for himself and I said I'd go halves. He don't know alot about boats so I'm doin work I'd have done anyway. Really we want to sell it. But if it runs real good he can buy my half from me. It would be worth it to leave my boat at home- hehe.

 

[Franki]

Re: old seized motor

Do it the old fashion way..<br /><br />take all plugs out, fill the entire thing up with 2 stroke mix... and shake it all around..<br /><br />if you can turn it over by hand to get the fuel all through it..<br /><br />then lay it on its back so the plug holes are facing down and again turn it over by hand... get everything out..<br /><br />let it sit for ages, occasionally turning over by hand.. till its all evaporated.. <br /><br />I have done that before as well..<br /><br />usually with smaller motors.. but I just did it to the 100hp I got.. it didn't really need it, but what the hell.. <br /><br />the motor purrs like a kitten now.. it hadn't run for over 7 years before I got it..<br /><br /><br />rgds<br /><br />Frank

 

[my new fishmaster]

Re: old seized motor

pb blaster to the rescue it works great fire a bunch in the cyls and leave it there. You will need a rebuild in the future but have some fun.

 

[Chinewalker]

Re: old seized motor

If it were mine, I would do a partial tear-down to satisfy my neurosis about having junk inside the crankcase. You could also do a simple clean-up of everything inside, free up any stuck rings and put it back together. Wouldn't cost you much - a few gaskets, and some sealer for the crankcase, and when you're done you've got a motor worth a few hundred bucks. Get a manual, preferably factory - but some of the aftermarkets are okay. Those 70s are great motors and well worth putting a few bucks into.<br />- Scott

 

[DJ]

Re: old seized motor

cut n jump,<br /><br />DO NOT USE CARB CLEANER. It will wash out any lubricant that is on the needle bearings. Then you will DEFINETELY have a heap of scrap.

 

[osly007]

Re: old seized motor

hey cut n jump just got through doing that to a 1985 60 hp johnson it spent 6 years without running when i got it the flywheel would not turn i took the cylinder head off new gasket 18 bucks about 12 bolts to take off then i got a good look down in there turned the motor till the carburators were looking up and got under there where the cylinder were and cleaned it with crc and a scouring pad that way everything runs down to the ground and not into the crankcase that got most off the rust out but my pistons were still sticking so took carbs out took reeds out and was able to unbolt connectin rod bolts and push piston outand was able to unfreeze rings and now she starts up great and has good compression but make sure everthing goes back the same way and they face the same way very important

 

[wheels4]

Re: old seized motor

I dont know if this will help but see if you can find a lubricant called kroil.This is not only a lubricant but also a cleaner.It will break all rust and dirt free from your rings.Soak cylinders real good and let sit over night.This stuff is by far the best.Good luck.Jonny

 

[Cut n' Jump]

Re: old seized motor

Being kinda lazy, cheap, and anxious I washed it out some more with some old weedeater gas. 125- 130 psi on each cylinder now. I greased the water pump, put the lower unit back on and fired it up! The plugs fouled real fast but I'm hopin thats from all the oil I ran through it. I ran it about 30 min. When i cleaned the carbs I only ran a wire through the mains and blew air through them. Looks like I'm taking them off now and replacing the impeller too.

 

[Cut n' Jump]

Re: old seized motor

Just thought y'all might like to know- that powerhead has over 100 gallons through it and she runs perfect. I did no disassembly,just flushed it with 90wt, carb cleaner, and old premix. I used the lower unit,carbs, and fuel pump from my old 70. Turns out all it[my old powerhead] needed was an exhaust gasket. Water was getting in the bottom cylinder.

 

[Hooty]

Re: old seized motor

Sierra hotel (sh*t hot)!<br />Now run it like ya stole it.<br /><br />c/6<br /><br />Hooty