Noise at Idle

[drifter]

Got a few motors out yesterday to run since the weather was nice and we had a big break in the rainy weather here in central Texas. All ran great with one exception – a 1957 Buccaneer 5hp. Although it ran great, it had a very noticable ticking at idle and was generally noisey. I am thinking a wrist pin that is worn. Anything else I should look for when I dissmantle it?
Thanks for suggestions.

[outbdnut2]

That model may have had a muffler on the carb air intake like Johnsons and Evinrudes did before fiberglass shrouds. I’ve gotten a couple old motors where this muffler was missing, and a lot of noise comes back through the reed valves and out the carb throat.
Dave

[frankr]

Wrist pin wear is not common in the 5hps. If you really think they may be loose, you can check them without dis-assembly. Remove spark plugs and sick a screwdriver in one of the holes. Slowly rotate flywheel while following the piston with the screwdriver (don’t push!!). When the piston is about half way down, stop rotating, then give a push on the screwdriver. Any clunk you feel is slack being taken up by loose wrist pin or con rod bearings. (Should not clunk). Repeat with other piston.

[kees]

.
clearance on the flywheel ?
check the key
you never know
.

[drifter]

Well, I took Frank’s advice and spent a good deal of time trying for a clunk. No clunk. So, rather than tear it down, I decided to replace as many moving/rotating parts as possible to see if some "slop" somewhere is causing the ticking. Replaced the armature plate, cam, and flywheel. Clicking still there. Crank keyway looks fine. Removed the starter and roped it, noise still there. Starts easy and idles great, but noisy. At this point, I see no option but to break open the case and have a look. To be honest, I seem to think that it may be something hitting the crankcase. It’s not super noisy, just more noisy than similar motors I own (56 Sea King 5hp). Any thoughts on anywhere else to look?

[fleetwin]

quote Drifter:

Well, I took Frank’s advice and spent a good deal of time trying for a clunk. No clunk. So, rather than tear it down, I decided to replace as many moving/rotating parts as possible to see if some “slop” somewhere is causing the ticking. Replaced the armature plate, cam, and flywheel. Clicking still there. Crank keyway looks fine. Removed the starter and roped it, noise still there. Starts easy and idles great, but noisy. At this point, I see no option but to break open the case and have a look. To be honest, I seem to think that it may be something hitting the crankcase. It’s not super noisy, just more noisy than similar motors I own (56 Sea King 5hp). Any thoughts on anywhere else to look?

Instead of pulling it down, perhaps you can just pull off the intake manifold and have a look inside the crankcases, perhaps you will see something marked up…

[Mumbles]

It sounds like your motor might have piston slap.

[billw]

I agree with Mumbles. However, if you have another similar motor, I think before I went ripping into the power head, I would try a quick lower unit swap. Lower unit noises can transmit upward and have fooled many a good mechanic. If you had, say, a chipped gear tooth, this might be something you could also hear in the power head area. I know you will never believe this, until it happens to you.

Long live American manufacturing!

[frankr]

Well it is possible that the screws have loosened in a connecting rod cap. If that is true, it won’t be long till the rod sticks through the side of the case, where you can see it.

[The Boat House]

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