Rod Click going over dead center

[jim-moffatt]

My Elgin16 has a noticeable click as the pistons go over top and bottom dead center.
It appears to be looseness in the roids, most likely top end bearing which is bushing. Bottom end is needle.
At mid stroke the rod play seems a little loose but in the range that I call acceptable – about 1/32 free play at flywheel rim.

Is it OK to run? There is not much I can do to fix it so :”Limited running?”

[Tubs]

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

• This reply was modified 5 years, 2 months ago by Tubs.

[jim-moffatt]

Thanks tubs looks like it may be something in the driveshaft or lower unit. I will investigate more. The click is coming primarily from the exhaust outlet. It may be the center driveshaft coupling which is near the outlet. This motor has a two piece driveshaft.

[jeff-register]

Go to TDC & set up a depth mic. Watch how many degrees of rotation of crank before piston moves, or use a pencil & feel the static movement of piston rotating back & forth. Maybe this helps?

[fleetwin]

It’s hard to say Jim….Not being familiar with Elgins, I don’t know how much rod slop is “normal”. It is fairly common for the little OMCs with needle bearing rods to have a slight clunk going over TDC/BDC, especially as they age. How hard is it to pull the gearcase off? You may want to pull the gearcase and rotate it again to rule out gearcase stuff. But, sure kinda sounds like rods if the clunk comes right at TDC/BDC. Could be something hitting under the flywheel like Tubs says, maybe just remove the flywheel and turn it over with a socket wrench.
Does it seem like both rods are “clunking”? Once all this other stuff has been ruled out, I would probably just start it up and see how it sounds. Doesn’t seem likely the both rods/needles are worn/have issues, unless there is rust inside the crankcase….

[jim-moffatt]

After a lot of oil and running with an electric drill the noise has gone away. All also feels well as I rotate it by hand. I hope to test start it within a week or so.

[Tubs]

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

[olcah]

I had the ring click described above by Tubs. It was on a 1956 30 HP Johnson. Through the exhaust port I measured the clearance between the ring and the width of the piston ring groove. I could see the piston move and contact the ring and hear the contact. The measured clearance was very well within Johnson’s allowable limit for that engine. I would make the check as Tubs suggests, You may not have a problem.

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