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Powerhead rebuild or not

FB, looked for some 225 rebuild pics! U still gonna post some! I'm curious how those caps work out for u! Had Nightshift yesterday so no rod cap alignment trials
 
Another round of frustration! I want to say these rod caps are giving me fits but today I worked with just 1 #3. Even went to Walmart and bought a big magnifying glass that idea turned out to be worthless. Maybe I'm being to critical
 
Update, today I spent some time on #1 rod cap. I did all the usual things to get the cap to line up but again could not get it perfect not even on one side. So I pulled the cap blew the joints out with compressed air and gave it another go but still no luck. So at this point I took the cap off and bearings out and tried to fit the cap to the rod with nothing in the way, still more of the same it’s not perfectly aligned. I quit and covered it up and have decided to look into 3 new rods, that will mean another tear down. I wished I had checked the rods before I pulled them apart to see how they felt!
 
Here’s some pics of the number 1 rod and cap
 

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Also this is not the first time the powerhead been into remember #3 had been bored 30 over. I wonder if the caps weren’t lined up back at that time?
 
I appreciate your bluntness and I can check with the shop and see if Mr. B will help out however maybe you have a suggestion or method that would warrant another try?
 
Factory new rods are listed at $270 each.-----And what if you have the same issue with them ??----Go find a shop to help you !!
 
Hey - great thread GGM - I am going to rebuild a 1977 Evinrude 75 hp 3 cylinder (long shaft). It has never been apart and is the last motor my Dad bought, so very nostalgic.

I highly recommend getting the Evinrude Service Manual. OMC wrote some of the best manuals ever. Much better than older Merc Manuals!
For the connecting rod caps -


The 1977 manual states:
(Caps are not interchangeable)


"To assist correct assembly, small raised dots are provided on matching sides of rod and cap.
Draw a pencil over chamfered corners on both sides of rod to make certain that cap and rod are aligned at this point. If not aligned, chamfered corners can be felt with the pencil point. Misalignment can be corrected by tapping cap lightly with a hammer and punch."
I think if the caps had been mixed up before - it would have caused bearing failure and damage to the rods and crankshaft.
It is hard to tell whether the caps are the "cracked" type or machined surfaces - but need to be clean and my opinion is no oil applyed to the surfaces.


I will definitely pay attention when I have to do it.


FYI the Service manual for a 1971 Evinrude - says the exact same thing!!!


My motor is 49 cu. in.


Thanks for all the pics and info /feedback from others - it is very helpful.


Allan
 
<p>
Rods have been the cracked design since 1950 on most bigger OMC / BRP motors.---Wonderful concept it is.-----Even the 10 HP in 1950 !!----Some of the smaller motors with aluminum rods and bearing liners were d / matched.----Nothing wrong with oil on the surfaces and bolts on assembly.</p>
 
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Hey FLT! Welcome to the forum!! Lots of great info here and top notch help and advice! Yes make sure before pulling them rod caps apart you take a sharp pencil and scratch it across the joints so you'll know absolutely how it feels! I wish I had done it!
 
R1, looks like I'm at a stand still for now. Rod caps have me locked up. Thought maybe I'd try to fab a jig of my own tomorrow. I understand you've built one! Any chance you could post a pic of it?
 
Ok, I guess it was another write up I saw. I tried again today for an hour or so what I'm doing is what FB recommend which was aligning one side perfectly so that's what I've been trying to do, at one point I felt like I had it but after I pulled it down a little I could feel a catch with the pencil. What do you think am I missing something? I use my 5/16 on my 1/4 drive nut driver handle and start with the rod cap bolts barely tight then hold the cap and rod together where it looks and feels close then tap tap with my small brass hammer when I get no catch I tighten hand tight if it stay I swap to the 1/4 ratchet but never seem to get passed that point as the pencil will catch.
 
R1/FB, hey guys I need the final say on these rods. Do I need to polish them with a green scotchbrite pad. Or is spray of brake cleaner and a white rag good enough.
 

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Also decided to try an experiment, I had the old rod bearings so I took the new out and cleaned up old ones and put them back in just to see if I could get that perfect alignment. No luck same results
 
Update everyone,
I pulled it all back down, I wanted to do a close inspection of these rods and caps. I dry fit each one just cap on rod and you can feel the connection between the 2 pieces and you would think they'd be perfectly fit together however they are not. I have no other explanation other than to say it's my best guess that when the motor was previously built care wasn't taken to make sure the rods and caps were correctly fit and mating surfaces were damaged when they were torqued down. I'm in the market for 3 rods
 
Pics of the caps, crank and rods
 

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<p>
Forgot to mention that the cap and rod on #1 were magnetized! The others weren't. Caught me off guard when the cap snapped right to the rod!</p>
 
Ok Anyone want to try and dry fit these rods and caps before I buy 3 new ones!!
 

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Just a quick update for everyone, I've ordered 3 new WSM rods and 3 new piston c-clips. Just waiting for them to hit the door so o can get back to square one.
 
Hi, I just saw this thread and read through it. I am retired U.S. Coast Guard and certified OMC technician. Now I run my own outboard repair shop. You did the right thing. Once OMC engines compression gets below 90 psi you are almost always looking at a rebuild of the powerhead. there are plenty of aftermarket parts available for OMC engines. Marineengine.com carries most all of them. Good luck with the rebuild.
 
Hey thanks for the reply and thumbs up on certified OMC tech!! I hope to make some progress when these new rods make it in! More to come!
 
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