Intermittently stuck motor

[ShortyLaVen]

Hello! I’m working on a ’59 Johnson 35hp RDS-21. When I first got it I couldn’t turn it over, and it was something in the LU that was suspect (cylinders look and clean when looking through spark plug holes). I never did figure out what the culprit was because eventually it just freed itself up after several tries with a breaker bar on the flywheel nut and toggling between gears several times. I chalked it up to a stuck bushing somewhere in the drive train and moved on with it. A compression check showed 100psi on both cylinders.

Then after sitting for a week while I was away camping/fishing, it was stuck again when I came back to it. It wasn’t completely frozen this time, but was very tight. At this point the spark plugs are still out and the flywheel is off, so I am turning it with a 30″ breaker bar on the flywheel nut still. Both gears and in neutral, both directions of rotation, still very tight. Then, out of nowhere, I feel some ratcheting while turning it, as if some splines or gears somewhere aren’t meshing. It does this a few times and then all of a sudden it’s completely free again.

Any ideas what could this be? As mentioned earlier, all it did was sit for a week in my garage between now and when I first freed it up. I have a “parts” motor that came with it (this one was supposedly a runner) that is in good shape, but missing a few things, so I was hoping to get this one running for the summer while I go through the other one. I can get pics later today of the whole thing, as well as any specific parts that you guys might want to see. Thanks!!!

[outbdnut2]

I had a motor behave strangely kind of like that and there were a couple vanes broke off the water pump impeller that were jamming things up so the driveshaft wouldn’t turn very far. Pull the lower unit off keeping the driveshaft with it and see if the motor turns over without it. The water pump will stay with the lower unit.
Dave

[fleetwin]

Is there water in the gearcase? Unfortunately, could be just about anything… I would wait until the next time it locks up, then remove the gearcase without freeing it up first. Removing the gearcase will at least tell you whether the powerhead or gearcase is locking up….. Any signs of water in the combustion chamber? You have the flywheel off, so that rules out something jamming up on the mag plate…

[Bob Wight]

The ratcheting feeling you describe could very well be a lower unit problem. I’d stop wrenching on the crankshaft and as the others noted, pull the lower unit off – you should then know pretty quickly if the problem is the lower unit or the powerhead. I recently picked up a used lower unit that had the same ratcheting sensation – it would turn freely for a bit, then bind up. Found a bad pinion gear.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[ShortyLaVen]

Thanks, everyone, for the replies! An impeller is on the to-do list, so I suppose that will be my next step now. I haven’t looked in the crankcase, but everything else on the powerhead, including the combustion chambers looks pretty clean to me. Is there any trick with the shift linkage or anything when pulling the LU on this motor? It’s my first outboard and I’ve never done it before.

[outbdnut2]

Just above the lower unit on one side of the exhaust housing, you will find a small metal plate with two screws holding it on – take that off and you will find a 2nd similar plate under it in the next housing – remove that too and you will find a coupling on the shift rod that has to be undone to get the lower unit off. You may have to move the gearshift lever to get that rod coupling bolt lined up with the access hole so you can remove it – you have to take the bolt out all the way because it goes into a curved slot in the rod. Be careful not to drop the bolt between the housings. When I reassemble, I use a small piece of duck tape to tape the bolt head to the outside of a socket wrench – this makes starting the bolt without dropping it very easy.
Dave

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ShortyLaVen

[ShortyLaVen]

Thanks for the help with the linkage! I managed to get the LU off, and I believe it is indeed the culprit. When rotating the drive shaft by hand it actually hung up a few times. I’m thinking it must be whatever bushing or the pinion as ‘bobw’ since the prob will still turn free in neutral even while the drive shaft is frozen.

On the plus side, it has a brand new impeller. Very soft and plyable. This motor also has brand new coils and points, so I’m guessing the PO had just done the water pump at the same time. Who knows, maybe this locking up problem is why the last guy gave up on it?

At any rate, I’ve decided to pull the LU from my other motor and just swap the whole unit. Thanks again everyone for the help!

[fleetwin]

Cool, glad you have a replacement gearcase! Make sure the gear lube is relatively clean and water free while draining the old lube….Make sure there is one and only one seal washer on each drain/fill screw… The unit must be filled from the bottom up, don’t attempt to fill it from the top hole…Do not remove that little phillips screw in the skeg or the shift linkage will fall apart inside….

[ShortyLaVen]

fleetwin wrote:

Cool, glad you have a replacement gearcase! Make sure the gear lube is relatively clean and water free while draining the old lube….Make sure there is one and only one seal washer on each drain/fill screw… The unit must be filled from the bottom up, don’t attempt to fill it from the top hole…Do not remove that little phillips screw in the skeg or the shift linkage will fall apart inside….

I’ll be sure to get some seals for the drain/fill plugs. Just looking at them I think I have some plastic fittings for bench bleeding master cylinders that would work good for bottom-up filling the gear case.

I also found a big crack in the old gearcase right near the drain plug. That explains why it was low on oil LOL!!

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