Fried Green Cylinders

[carlisle]

Crap! Rebuilt my 25 horse, 1975 'rude lower unit for slipping dog clutch at high power settings.<br /><br />Took it out today, started right up, solid forward gear, great fun motoring across the lake....for about 1.5 minutes when the engine slowly died, followed by a nasty smell. You guessed it, no water from the coolant exhaust. Must have misassembled the lower unit to somehow make the pump inop.<br /><br />Brought her home, took off the head. Both cylinders slightly scored, easily smoothed with ScotchBrite cloth. Forgot to check compression before disassembling head but both cylinders try to suck the palm of my hand in when placed over the top and pulled through.<br /><br />So, the question. Does an overheat and seizure automatically mean the thing is toast and needs a complete removal/ring job or is there hope?<br /><br />Chris Carlisle<br />Sioux Falls, SD<br />1975 Evinrude twin, 25 HP

 

[alcan]

Re: Fried Green Cylinders

While this sort of thing is not good. Those cyls could have been scored for years. Of course it is almost impossible to make a reliable call sitting here (no can see). I think you could just slap a new head gasket on her and go. I would look into the water pump and cooling system first. What happened to testing your work when you finish the job? If you worked at a dealership, you would probably be lookin for a new job tomorrow. Nobody is perfect, you have to double check, then check again.

 

[carlisle]

Re: Fried Green Cylinders

Yes...The testing thing. Well, I meant to. I thought about filling up the old 55 gal. drum and all but decided to do my testing in the lake instead. Meant to check output of the water exhaust before twisting the throttle but in my excitement after my first rebuilt lower unit, forgot. Man was that a sick feeling when after it quit I caught a whiff of that smell and new right away exactly what had happened. <br /><br />And yes, you're right, now that I've got a little better handle on what's going on above the shroud, I'll take the lower unit off again and see what the heck happened there. <br /><br />Here's crossing my fingers and hoping for adequate compression.<br /><br />Thanks,<br />Chris

 

[voodoo]

Re: Fried Green Cylinders

An oh seizure is better than an lack 'o lube.<br />You may get away with it..run double oil for a bit.

 

[carlisle]

Re: Fried Green Cylinders

Whew!!! It worked. Local dealer had the head gasket in stock, installed, checked compression (105 lbs. each), filled up 55 gal. drum, crossed fingers, pulled starter, BINGO. Boy, did I get lucky. Thanks Evinrude for making the pistons and cylinder sleeves tough enough to endure any idiot's abuse.<br /><br />BTW, the water pump wasn't working cuz I didn't align the little pickup tube with the impeller housing before re-mating the LU to the motor. It was just pumping the cooling water back into the LU. Another silly mistake. If we didn't learn from them...well, let's just hope I did.<br /><br />Chris