CD11 Need advice

[nwcove]

Re: CD11 Need advice



not sure if these pistons are worth using or not, but there they are. the piston on the right had broken rings ( probably my bad, as i didnt give it much soak time). pics are both intake and exhaust side.
hopefully others will chime in and give opinions on their condition.

 

[Stickler]

Re: CD11 Need advice

They look alot better than the ones i have, they have some wear on the skirts just from moving up and down, but they dont look scored or pitted at all, do you happen to have a caliper to see if there in spec, either way, they look good to me, maybe someone else has an opinion,but used pistons are never gonna look new, as long as they have there pins in each ring groove and there not loose id say there good.
I was also wondering if anyone knows where to get replacement rings, the end gap on mine are way out of spec and should be replaced.

 

[HighTrim]

Re: CD11 Need advice

Believe it or not, there are a couple vendors on ebay right now with very cheap ringsets. I bought 4 sets for the 35hp Big Twins last week for only 10 bucks a cylinder. They were NOS. I bought all 4 they had.

 

[Rick.]

Re: CD11 Need advice

That s a great price. I looked at nymarine and for rings he wanted 48/piston and didn't seam to have and for 5.5's, just 7.5 and up. Rick.

 

[Stickler]

Re: CD11 Need advice

So i whent onto marine engine to use there parts look up and am now a little confused, rings for 1955 cd12 is #41223, 1956 cd13 #41333,and then from 1957cd14 all the way to 1979 the part # is 0378432, dont know if the 1955-1956 part numbers are just old part numbers and take the same as later models,any input appreciated.

 

[HighTrim]

Re: CD11 Need advice

0378432 is the current part number.

Evinrude Johnson OMC 0378432 - Rings, Standard @ MarineEngine.com
New OMC Johnson Evinrude Ring Set 378432 NC3484 | eBay

 

[HighTrim]

Re: CD11 Need advice

0378432 is the current part number.

Evinrude Johnson OMC 0378432 - Rings, Standard @ MarineEngine.com
New OMC Johnson Evinrude Ring Set 378432 NC3484 | eBay

 

[nwcove]

Re: CD11 Need advice

The ring end gap should be between .005 and .015. The total clearance between piston and cylinder should be .0013 to .0025. Your piston diameter is 1.938"

my $20 micrometer shows ( depending on how square i can get it to the pistons) anywhere from 1.936 to 1.400 as measured at 90 deg to the wrist pin on either piston.

 

[HighTrim]

Re: CD11 Need advice

I messed up there, meant to say CYLINDER BORE is 1.938"

Now if your piston is 1.936 it should be fine.

In fact, if there piston is not gouged/severely damaged, they are almost always fine. The cylinders seem to get out of round, and worn, first.

 

[nwcove]

Re: CD11 Need advice

still not sure if the pistons are worth the shipping cost to stickler, both are scored somewhat, but how much is to much?

 

[HighTrim]

Re: CD11 Need advice

Hard to find alone sometimes.

Here is only 1 for 50 with shipping

Vintage 1960's Johnson 5 5 HP Sea Horse Piston Assembly Bearings Rod | eBay

 

[nwcove]

Re: CD11 Need advice

thanks Chris!

 

[Stickler]

Re: CD11 Need advice

hey guys, so i found a good source for rings, 23$ a set, not too bad, id definetly still be interested in the pistons, i just hoping someone might have commented on condition, and if they were reusable, again , there better than what i have now, im just no expert on used pistons, and if the scoring will affect function or not.
Anyway, let me know the cost of shipping if you happen to know,or pm me,thanks again guys.

 

[nwcove]

Re: CD11 Need advice

i was also hoping to get a few opinions on whether or not the pistons looked worthwhile re-using as im not sure either.

 

[HighTrim]

Re: CD11 Need advice

I normally dont like to comment on using used parts on a forum as if things go south I would not want to be blamed. Way too many variables ranging from unseen damage from pictures to the installation techniques of the buyer.

However, that being said, from what I can see, and if it were my motor, I would use them. Those light scratches wouldnt worry me. Re ring, and hone the cylinder and you are off to the races.

When I sell used parts like that, I usually want a bit of reimbursement, mainly for the time it takes to rip a motor open, clean the parts, package them, drive to the post office, ship them, etc etc etc....