pistons frozen up

[isimar]

i got this 1971 thompson with the 4cyl mercruiser.. as i've said above, the engine is seized up... i've removed the spark plus and filled all cylinders with marvel mystery oil and will let soak for a couple of days....my question : if i put the tranny in gear, would turning the prop spin the engine ? this doesn't have a visible pulley or harmonic balance to apply an impact wrench and don't know if "tunking" the starter would be the right thing to do.... from what i read, you guys seem to have been through every situation know to a boater, any help would be greatly appreciated.

the motor is( i believe) a 2.5 liter

 

[Don S]

Re: pistons frozen up

You might as well pull the engine out of the boat and take it apart and see what is actually salvageable.

The fact that its rusted means the rings are stuck in the pistons, and the cylinder walls are probably scored and pitted from the rust. You might get it broken free, but it will never be right.

PS, you can't push the prop hard enough to turn the engine if it wasn't seized.

 

[isimar]

Re: pistons frozen up

well, you've given me some hope that the engine may be fine, i'll put a battery in the old girl and see if she rolls over..if not....i'll be on the internet looking for a rebuild kit. thank you.

 

[Don S]

Re: pistons frozen up

well, you've given me some hope that the engine may be fine

Didn't mean to, until you pull the head you have no clue how bad it is.

 

[isimar]

Re: pistons frozen up

geez, it would've been easier on me i you'd have told me my wife was cheating on me !

 

[Don S]

Re: pistons frozen up

Then I take it back. Get it broke free and it should run like a brand new one and never give you a minutes problem.

How's that ?

 

[isimar]

Re: pistons frozen up

oh thank god.....i was beginning to worry.

thanks don, there's no way i can doubt you....looks like it's game on with a rebuild.

 

[mjfink]

Re: pistons frozen up

Then I take it back. Get it broke free and it should run like a brand new one and never give you a minutes problem.

How's that ?

ROFL. Sorry to the OP, but this was just too funny to let go by. If it makes you (the OP) feel any better, my engine is currently apart getting a top end job and just had to buy a full new set of dry joint exhaust. So, I feel your pain.

Don; how can I fix my engine without taking it apart? Just pull the plug from the cylinder with bad compression and a bent valve? Will I lose any power, or will it be good as new?

 

[Don S]

Re: pistons frozen up

Next time, just post what you want to hear. Then all we have to do is copy and paste and you get the answer you want to hear. Then we don't have to waste all our time typing out the truth.

 

[isimar]

Re: pistons frozen up

gotcha !
at least i'll have someone to blame instead of my self.....the wife....you know how it is...

 

[isimar]

Re: pistons frozen up

off subject ...why is it when i click on anything at the top of the page to search for parts, it starts at the page i need, and then it switches to a blank page ?
i'd like to order from this site if possible.

 

[fishrdan]

Re: pistons frozen up

Were the plugs rusty? If no, continue reading...

You could have a locked up drive, stopping the engine from turning. I'd pull the drive and see if the engine turns over

 

[isimar]

Re: pistons frozen up

Were the plugs rusty? If no, continue reading...

You could have a locked up drive, stopping the engine from turning. I'd pull the drive and see if the engine turns over

the plugs weren't rusty, just the black sooty carbon on them. does the drive lock up from long storage time ?

 

[Bondo]

Re: pistons frozen up

the plugs weren't rusty, just the black sooty carbon on them. does the drive lock up from long storage time ?

Ayuh,... Welcome Aboard,.... Anything is possible,... it mighta been broken when last shut-down,...

Everything in the drive, but the propshaft turns with the crankshaft....

Have ya checked the oil levels in both the motor, 'n drive,..??

 

[isimar]

Re: pistons frozen up

Ayuh,... Welcome Aboard,.... Anything is possible,... it mighta been broken when last shut-down,...

Everything in the drive, but the propshaft turns with the crankshaft....

Have ya checked the oil levels in both the motor, 'n drive,..??

haven't checked fluids yet, sitting through a nasty thunderstorm now so i'll do it first thing in the morning.
i tried to turn the prop by hand with the plugs out and "assumed" it was seized up.

 

[Don S]

Re: pistons frozen up

Take the drive off and see if the engine turns.

 

[isimar]

Re: pistons frozen up

will do..i put the boat in gear thinking i could turn the engine with the prop....out of gear the prop spins free.

 

[fishrdan]

Re: pistons frozen up

out of gear the prop spins free.

You could have trashed upper gears/bearings, and the lower still spinning free...

As Bond-o suggested, remove the top vent screw and see if the drive lube is low, and how low, if it's low.

 

[isimar]

Re: pistons frozen up

well, stuck a battery in it, bumped the starter and she rolls over . next step, change to electronic ignition, change fluids and filters and try to fire her up....then we play proctologist and go after her rear end area and take the drive apart...feeling better already.
after that, we update everything i can find..