1991 E25 Klickety Klack

[Kplusten]

Am stumped as to what is making rattling sound in my trusty motor ELEID. Initially thought maybe just external lift locking lever was vibrating, it is loose/worn at pivot point, put a bungee cord on it, no improvement. Motor runs great, smooth idle, slightly rougher in mid-range, jumps onto strong 5200 RPM WOT.

Have owned it for about 8 years, run it hard.​

Could this be caused by a worn out lower unit? Or maybe mechanic did not replace some shims when he changed LU seals a year ago after I noticed some water in oil? I think the rattle has gotten worse after that but it has always sounded funny to me. I wouldn't dare drive a car that sounded like that. I note at least 1/16" in/out play of propeller shaft, mechanic said it is not uncommon. Could that be it? Or worse yet, maybe worn powerhead roller bearings? Waiting for something to break so always have a trolling motor to get back home. Not trying to create a problem if there is none, so if you seasoned mechanics tell me to stop listening to it and just keep fishing, that is what I will do. What does it sound like to your experienced ears? See link for video/audio.
https://youtu.be/q_agwIq6vUc

 

[racerone]

Sorry-----No point blaming the mechanic here.-------There are no " shims " in that lower unit.

 

[TrueNorthist]

I'll place my neck on the block... Appears it's running a bit rough at all rpms and shaking abnormally. Have you determined both plugs are sparking equally and there's no issues with reeds? From what I can discern it sounds more like vibrations from some sort of misfire.

 

[TrueNorthist]

I shoulda said, test ignition output with an air gap tester. Anything less is uncivilized.

 

[Kplusten]

Ok, racerone, wasn't trying to shoot the mechanic who is my friend, but many larger OMC LU's do have complex driveshaft shim measurements, not applicable to this motor or $200 seal repair. I didn't have a puller to do it. Thank you for not putting your reply in all CAPS!!! I love to read your replies to many boaters' problems, so thanks for looking. So, is the rattle maybe related to the play in the prop shaft?
TrueNorthist, this motor starts on first turn of key with primer, does not stall, and runs okay at low idle for trolling for hours. I have tested the spark with an open air tester at about 7/16" and it is sharp and blue for both cylinders. Compression is 115 upper, 120 lower. Both were 125 psi when I bought the boat. Maybe I didn't capture the rattle noise well enough with my cellphone? I had to change some motor mounts a few year ago, maybe worn from rough running vibrations? Not an expert, so appreciate any and all inputs.

 

[oldboat1]

Might try replacing the head gasket.

 

[Kplusten]

Sorry Oldboat1, I'm confused. Water was in LU, not in cylinders. Almost equal compression, don't suspect blown head gasket. What would I be looking for with head off? Maybe worn rings allowing pistons to slap? Is compression that low to warrant pulling the head? Sitting right in front of the motor when underway, the klackety klack noise is much more noticeable than in my video. Can pull the head at end of boating season if you feel it is warranted. Looking for possibilities for scary noise here, thanks for input. Would prefer to not have it fail catastrophically.

 

[oldboat1]

A new head gasket might address the noise and the slight difference in compression. Not a difficult job. While the head is off look over the cylinders/pistons. If looking for a shortcut, you might loosen and retorque the head bolts.