Evinrude Big Twin starting/running issues

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Newtosa

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Does anyone know if flywheel 580335 (1959 Evinrude 35hp) is compatible with flywheel 580334 (1961 evinrude 40hp)? Background and details below.

I'm restoring a 1961 evinrude 40hp (35524). The old flywheel (presumably it was original, pn 580334) had a bad taper, bad keyway, etc. (broken crankshaft looked like a big explosion). I found a flywheel from a 1959 35hp (I think pn 580335), and it started after considerable effort, but it runs terrible.
. Confirmed fuel (bulb squeeze fills high speed circuit, and when running I can see the jet delivering fuel with the carb screen off at lower throttle)
. Compression is 105 top, 110 bottom (I honed cylinders, etc.)
. Confirmed decent spark across 1/4" gap using the basic gap tool
. Points gap is. 020 when the inspection port is right above the points (and cam is at high point for that cylinder)
. I don't have a timing tool for this engine, and the flywheel has absolutely no markings, but the points open and go to infinite ohms at two points I marked with a sharpie, pretty much exactly 180 degrees apart on the flywheel
I can't get this thing to run more than 45 to 60 seconds no matter what I do. Could it be the flywheel is that different? looks so similar.
Magnet size and shape looks just like the old one that came on the engine, but I'm just not sure.
 
What I can tell you is that the 1960 and 1961 40hp engines suffered a LOT of broken crankshafts. So.....some of the replacement powerheads that were being sent out may have had a physically larger crankshaft as well as a physically larger driveshaft. The 1962 40hp had the larger crank and driveshaft and was once again, bulletproof.
You may or may not have the small crankshaft. If you do the 1959 should work. Put it on the taper and take a look at it. That is what I would do.
Now, as far as the points open/closed position goes? That is controlled by the cam on the crankshaft. Flywheel has zero to do with that.
The flywheel magnet location on the hub has a bunch to do with the way an engine runs though. See if you can tell a difference in location between the two flywheels you are looking at.
 
Thanks Pappy. I have the smaller crankshaft. Cam wasn't there when I got the engine, so I ebayed one. Looks right, fits the pin, and opens the 2 points 180 degrees apart.

Flywheel taper fits nicely, and everything is snug when it slides down on the Woodruff key. Last unknown is whether the magnets are located right for this magneto. They look the same.

Rather than just looking at it and guessing (since part numbers for the magneto plate, coil, and cam are the same, if the taper seems right it's probably OK), I was hoping someone might know for sure whether the 59 flywheel fits the 61 engine.
 
He he he. I wish just one word of what you said was true. When I bought it, it was a pile of parts. History unknown, and the prior owner lied about a few things, so I've just approached this one with a bias that I need to verify everything.

First part I bought was a replacement crank shaft, and this is my first "rebuild everything" project. I've gotten the manuals, done a lot of reading, obsessed about when to use omc sealer 1000 vs 3m 847 vs permatex aviation vs nothing, and many other decisions. So far this was the first day I've attempted to get it started. I got it to start 20 or 30 times, but I haven't been able to keep it running longer than a minute. The first 6 or 8 times it coughed and sputtered and tried to jump off the stand and into the barrel, and as it got warmer it settled down a little but still has some pretty rough coughing fits.

All my other engines have been (mostly) running when I bought them, so this one is teaching me a lot more.
 
Then you may not like what I will tell you.
Unless you are absolutely sure....purchase OEM ignition components, carb kit to start with.
The Sierra coils do not fit and the center shoe does not come close enough to the flywheel magnets to produce good spark. Their points do not line up.
Condensors are iffy at best. Carb kits do not include everything to properly rebuild a carburetor. You get the idea.
 
All oem parts replaced, in the ignition, carb, fuel pump.

I realize there are multiple possibilities, so I'd like to eliminate the flywheel issue, if anyone out there has knowledge of whether the one I'm using is compatible.
 
I cannot think of a single difference in those two basic engines that would make a difference in the magnet location of the flywheel.
Secondly, if the magnet locations were different the timing would be different. Have a timing light? Use it.
Third, the flywheel would give the same exact characteristics every single time you start the engine. It would not "settle down" as the engine warmed up.
"Coughing fits" are most commonly caused by a lean engine, vacuum leak, low float level, etc. Those characteristics will change a bit with engine temperature but static timing will give the same issue each and every time.
 
If a motor starts and runs you likely don't have far to go.... Tell us about the fuel pump ? Original ? Rebuilt ? Cheap replacement ?

comparing the part numbers:

https://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1959&hp=35&model=RDSL-21&manufacturer=Johnson&section=Magneto+Group

https://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1961&hp=40&model=RDS-23&manufacturer=Johnson&section=Magneto+Group


There are differences in many parts. This could be caused by the mid year crankshaft changes, but it's also possible that there are subtle differences in several parts. An engineering driven company like OMC doesn't just change a part number without some valid reason, so If simple methods don't work to get it going, it could very well be some subtle difference in parts that were used on your rebuild. Note that even the throttle cams are different part numbers.....interesting...
 
Pappy, thanks for the advice ; all makes sense. This weekend I'll dig into possible fuel and vacuum issues.

Shaugh, makes sense, and I had scanned the marine engine parts lists (and even what's on offer on ebay) for some intel on the flywheels... can't tell any difference. I also have both flywheels, and they look the same to me (although the "correct" one is no longer fit for service as the Seloc manual likes to say).

Thanks guys.
 
Thanks everyone. After a really close inspection of the original flywheel (taper is damaged; too much wobble) and the 1959 flywheel (my replacement flywheel), I'm satisfied these are the same.

I'm moving on to confirm sync and link (this works a little differently than the early 70s motors I'm more familiar with, but I found some original service manuals that are much clearer than the Seloc), then re-check carb, then eliminate potential leaks on the intake side.
 
Hi all, a couple of updates here. I spent the morning reading some other threads on timing and carbs (and re-reading the service manuals). Really appreciate all your help and advice.
1. Spark: confirmed spark with plug in boot and alligator leads from side electrode to ground.
2. Points: I did see that the #2 point alignment was really sloppy (the rocker side was nice and even, but the common side was too high and also just angled wrong... I could see air space between the "closed" points and the armature plate). I took some 320 sandpaper to the common side but never got happy with it, and when adjusting the height I broke the plastic insulating layer. These are omc parts. I went back and compared that common side point to some old omc (and unused sierra) parts, and it's just no good. Swapped out, replaced, re-gapped, re-timed, and slid in a card dipped in acetone.
3. Timing: I got the timing tool from Richard at classicomctools, to confirm my points were opening at the right time. All was good there, and I used that reference to mark my flywheel (I'm obviously just not seeing /feeling the factory markings, but it doesn't matter anymore because I have nice new sharpie lines now).
Still to do :
1. Sync and link: I had some slop in the carb roller cam, and I wasn't familiar with adjusting the eccentric plastic bushing, so I think the butterfly was opening late. Will pull flywheel and look at this again. I also don't yet have the stop collar on the throttle /carb link bar positioned quite right yet, so will do that while flywheel is off.
2. Fuel: I'm going to take the carburetor apart, confirm float and needle seat operation, confirm open jets and passages, test idle and high speed circuits again, and make sure everything is there. It's all a brand new omc kit.
3. Vacuum: this is the first time I've opened a crank case, so I re-read some service manuals and went back to look at my photos from the process (mostly checking hardening vs non-hardening sealers, thread sealers, etc). Everything in the crank case looks right, seals are oriented correctly. Torque values are all correct. All that said, I didn't use any sealer on the intake gaskets (intake manifold to reed plate, or reed plate to block). That (and the head gasket) is the only place I didn't use gasket sealer. Every gasket on the engine is new. At the time, I read some threads, and the consistent advice was not to seal new gaskets on the intake side, but the condensed service manuals seem to indicate everything should be sealed: "the crank case and intake manifold must be completely sealed against both vacuum and pressure." What do you guys think on this one?
 
I'll get after #1 above (confirm sync and link) and #2 (confirm fuel delivery) this weekend when I get back to this engine. I found the photos for #3 above (gaskets for intake manifold to reed plate, and reed plate to block). I thought I had decided not to seal these, based on a few threads I was reading at the time.

Question for the group: was this a mistake, and could it be the cause of the sputtering and coughing?
 

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intake manifold to reed plate
 

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It's a theory... although I have my doubts that a tiny vacuum leak would do much.... a 2 cycle motor of that vintage is an incredibly crude device.... but sealing it can't hurt.... I'd do that and only that to see if it makes an immediate difference....

That's the problem in diagnosing a motor.. often times you do a bunch of things and then hope you found it... but never really knowing that you found it.... Take your corrections 1 at a time and see if you can pinpoint it... you'll sleep better than if you never really know for sure what was wrong...
 
Thanks Shaugh; I agree... I prefer to test 1 thing at a time to know exactly what caused something. Based on strong counsel on mareinengine and iboats forums not to seal intake gaskets, I'm going to look for other causes, at least for now. I'm going back to confirm sync, link, and fuel.
 

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