unsticking rings and rod bearings

[orlandoclippertim]

I have an evinrude rd-17 1954. I bought it for 35$. I have completely dis-assyembled the powerhead as the start of a overhaul. Cant feel any ridge at the top of the cylinder walls- so i am suspecting not too much wear there. However the upper and lower rod bearings are a little loose. (upper bronze bushing, lower needle) The mains seem to be in better shape- probably just clean them. No signs of extreme heat- ie no blue surfaces. The lower piston however seems to have some carbon build up on the skirts and I see that there is some fine carbon that has packed into about half of the ring circumfrences on that piston -the carbon has got the half of all 3 rings stuck in the groove. It is soaking in blaster now. Is there a specific treatment I can do to the piston/ring to help loosen the caked carbon so i can remove the rings safely without risking breaking them ? Will boiling water work ? (have heard that)

I am planning on hoaning the walls (if they mike OK) and reusing the rings after cleaning the pistons and grooves. (is that kosher?)

I will be looking for a source for needles and bushings for the rods. (and rod bolts.....) This engine has blue steel allen head bolts as rod bolts- could i use regular domestic alloy steel grade 8 from hardware as long as dimentions the same ?

This is my first rebuild of a boat engine. have done antique cars and planes but my first outboard.
(I have electric penciled the rods, caps and pistons to not get them mixed up in order or direction)

any general guidance and things to watch out for will be warmly welcomed !
lookin forward to seeing what I can do with it !

Tim

 

[kodibass]

Re: unsticking rings and rod bearings

there is a video on u-tube, an old timer shows how to remove stuck piston rings with a nail and tap hammer, I would use the original rod bolts. if you are reusing the old rings only lightly hone the cylinders just enough to break the glaze. good luck

 

[JB]

Re: unsticking rings and rod bearings

If your outboard is truly a RD-17 it is a 1955 Johnson 25HP, not a 1954 Evinrude, Tim. That might make a difference when you get around to ordering some parts.

Good luck.

 

[robert graham]

Re: unsticking rings and rod bearings

Carbon-stuck rings can be a challenge to free up without breaking them, but I spray them with carb cleaner and then with a small probe, tool or screwdriver start at the ring gap and gently get between the ring and the piston groove until ring starts to move, more carb cleaner, take your time and keep working with it until ring is loose. Carbon is so inert that most solvents don't do much. 3M Scrubbing pads are good to clean carbon off piston rings, grooves and skirts without scratching. Good Luck!

 

[boobie]

Re: unsticking rings and rod bearings

Mix up some ATF and Acetone 50/50 and try soaking your pistons and ect in that.

 

[Scott Danforth]

Re: unsticking rings and rod bearings

use oven cleaner, hose it down, let it sit, then use brake cleaner. will probably not even need to pull the rings