Is my powerhead toast???

[fsujack21]

I was having some stalling issues while changing gears on my 1981 evinrude 115hp crossflow at the end of last season. I had done a lot of work to her in the spring (head gaskets, waterpump,plugs,wires, rebuilt carbs, fuel lines decarb treatments, filters etc) so i figured it may be just a batch of bad fuel and winterized it. Well I was getting her ready for the spring and found my compression to be about 90psi in 3 cylinders and 60psi in the top starboard cylinder. I pulled off the head and found this:



Unfortuneately, I think I know the answer to this alreadyu but, money is very tight these days and I was hoping to nurse the engine though one more season. Any chance that this is not toast?

 

[1946Zephyr]

Re: Is my powerhead toast???

Well, how do the cylinders look? Are there any scores or gouges on the cylinder walls? The crowns of those pistons look good, outside of the carbon on them.

 

[fsujack21]

Re: Is my powerhead toast???

the inside of the cylinder walls are fine, no scoring. My concern is the separation on the port side outer wall of the cylinder. I assumed that with the metal separating that I will not be able to ever get the compression back up.

 

[daselbee]

Re: Is my powerhead toast???

Oh jeez....now that you point it out....it is done.

Wonder what caused such damage? Ouch.

 

[fsujack21]

Re: Is my powerhead toast???

ok thanks. thats what i thought. My guess is that late last season i had a drive shaft break while running at a decently high rmp, then with out the resistance I had a very high rpm spike which i throttled back right away but i think the damage was done. it ran with a used lower unit that i picked up for the last few week of the season but it was never right.

 

[Chinewalker]

Re: Is my powerhead toast???

Corrosion gets between the cylinder sleeve wall and the casting causing it to bubble out like that. Motor can't be saved - the cylinder sleeve is no longer supported and won't stay round...

 

[aerobat]

Re: Is my powerhead toast???

when money is tight- how does the engine perform with the 60 psi cylinder? if sufficient- put it together and just run. you cannot do much else here.

 

[fsujack21]

Re: Is my powerhead toast???

it runs so/so. It often stalls when changing gears and it is tough to start. I know the damage is done and the motor is shot but I was thinking that if i bumped up the idle speed I might be able to get by until I save up for a new motor. Any thoughts of how to nurse this thing along or do you think I'm just wasting my time?

 

[aerobat]

Re: Is my powerhead toast???

well, any hint is of course hard core nursing- like said the sleeve is no longer supported and thats the reason for the compression loss.

my thought would be - try ring free ans see if it helps a little to improve compression. when available you may try oversized rings. or when you are firm in screwing try to get an cheap used block since the crankshaft, pistons, rings etc seem to be good. the used block is the most solid solution.

 

[nwcove]

Re: Is my powerhead toast???

dont go far and get a good kicker motor.

 

[fsujack21]

Re: Is my powerhead toast???

Ok thanks for all the quick responses.

 

[boobie]

Re: Is my powerhead toast???

Did the head gasket blow in that area ??

 

[fsujack21]

Re: Is my powerhead toast???

I didnt see any noticle signs of a blow-out in the gasket. No overheat issues and the gasket was less than a year old.

 

[boobie]

Re: Is my powerhead toast???

If you want to try something really wild, go get some gray marine-tex and clean up the area really good. Pack the marine tex in it and after it hardens file it it off so it is flush with the block surface. Then put some OMC gasket sealing compond or permatex # 3 on the new head gasket and torque it down good. It may get you through another season. Done this yrs ago but that's another story.

 

[tx1961whaler]

Re: Is my powerhead toast???

If you want to try something really wild, go get some gray marine-tex and clean up the area really good. Pack the marine tex in it and after it hardens file it it off so it is flush with the block surface. Then put some OMC gasket sealing compond or permatex # 3 on the new head gasket and torque it down good. It may get you through another season. Done this yrs ago but that's another story.

Kind of did the same thing once, but used Devcon Aluminum. What can you say? Not a whole lot to lose here considering.....just say YEEEEEEE HAWWWWWW!, (and make sure you have towing insurance)

 

[wired247]

Re: Is my powerhead toast???

Kind of did the same thing once, but used Devcon Aluminum. What can you say? Not a whole lot to lose here considering.....just say YEEEEEEE HAWWWWWW!, (and make sure you have towing insurance)

He does have some good internal parts he could lose. Considering he could get a 115 block for a couple of hundred bucks he's going to need intact pistons and a crank/rods etc.

 

[boobie]

Re: Is my powerhead toast???

Did that yrs ago on a 1969 85 hp mtr and the mtr lasted 3 yrs the last I heard. Good Luck.

 

[1946Zephyr]

Re: Is my powerhead toast???

Yikes. I didn't notice that blow out area.

 

[emdsapmgr]

Re: Is my powerhead toast???

Even if the engine has not thrown a ring yet on that bad hole, the engine won't last long the way it is. The cylinder casting has expanded so much, cooling water flow around that cyl will be signficantly reduced while running. That means you've got a hot spot on the side of that cylinder. Won't be long before there is an internal cyl overheat, causing a ring to break and probably a piston to scuff. May not even get a head overheat warning prior the the event.

 

[1946Zephyr]

Re: Is my powerhead toast???

Well, a good used 31 year old powerhead should be reasonably priced at most sources. I would go that rout.