Boys...I've Got Me A Rattle

[Jason2tpa]

Past few excursions I'm hearing a very faint, yet noticeable to me, rattle coming from under the top cowling. It's happening in neutral and low idle rpms, though when in neutral it's less a rattle than when in gear. Doubtful anyone else would even hear it, but just like y'all, I know exactly how my engine sounds.

Prior to doing some investigation I thought for sure it must be the flywheel's cover...perhaps a grommet popped off causing the cover to knock against the flywheel. But nope, wasn't the cover. Took it off and I could still here the rattle. Checked 360 around the engine, looking for loose connections, loose bolts, etc. All looks normal to me.

I'm sure y'all like a description of how this rattle sounds...but I'd be foolish to even attempt. Just know it's not a clicking, not a grinding....more like...a rattle. Engine is performing like a beast, per usual. I'm at a loss. Your thoughts?

[JerEazy2]

Checked it out of the water? Lower unit not fully engaging rattling the shift selector rod? (That may not be the right term)

[pstephens46]

Can you post a video/audio?

[robert graham]

My black plastic shift rod connector( the one that slides in that tray-like device and requires grease) was rattling at certain RPM's.....wrapped some of that plastic spiral wrap cable stuff around it...just enough to allow movement but no rattle....no more rattle ever again.....

[pstephens46]

Does it rattle in driveway, running on hose, with cowl off?

[Jason2tpa]

Does it rattle in driveway, running on hose, with cowl off?

Yes. When I gave it once over the cowling and flywheel cover were also off, while engine running on muffs. Put my ear close to each side of engine but couldn't pinpoint the rattle. If I fet on boat tomorrow I'll take a video with audio.

My black plastic shift rod connector( the one that slides in that tray-like device and requires grease) was rattling at certain RPM's.....wrapped some of that plastic spiral wrap cable stuff around it...just enough to allow movement but no rattle....no more rattle ever again.....

I'll tale a closer look there robert, thanks.

[DennisG01]

What engine?

If you're positive it's external to the engine, then it should sound louder on one side or the other... or front/back. This shouldn't be too hard to at least get in the general area. Then just start looking closer or actually touching/putting pressure on various things. Once you get it to stop, you've narrowed it down.

[panasonic]

Engine on it way out Jason, start looking for another.

[Jason2tpa]

What engine?

If you're positive it's external to the engine, then it should sound louder on one side or the other... or front/back. This shouldn't be too hard to at least get in the general area. Then just start looking closer or actually touching/putting pressure on various things. Once you get it to stop, you've narrowed it down.

Thought my signature with engine info was included with each of my posts...obviously it wasn't. Thanks for reminding me. You make a valid point, no doubt. Because the sound of engine running drowns out the rattle, its making it difficult to locate where on the engine it's coming from. As I previously mentioned, the rattle is faint. So faint that if I asked someone if they hear it they'd probably wouldn't. But I do. I only spent a few minutes my first go around, will need to dedicate more time tomorrow.

As far as if I'm positive it's external.....well, I guess I can't be 100%. In my mind, if it were internal after all the hours I've run it with the rattle I'd think the engine would not be performing normal as it is.

Geez, I hope it's not internal.

[Jason2tpa]

Engine on it way out Jason, start looking for another.

Oh boy pano, don't say that man. She's my baby and runs like a screaming beast. No doubt she's up there in age, but been very well maintained throughout.

[Jason2tpa]

What engine?

If you're positive it's external to the engine, then it should sound louder on one side or the other... or front/back. This shouldn't be too hard to at least get in the general area. Then just start looking closer or actually touching/putting pressure on various things. Once you get it to stop, you've narrowed it down.

Thought my signature with engine ID was being shown. Guess not. Thanks for reminding me. The rattle is so faint that when the engine is running it's drowning out the rattle, making it difficult to locate. I only spent a few minutes searching the first go around. Will spend more time tomorrow.

As far as if I'm 100% it's external...well I guess I can't be 100%. However, in my mind if it's an internal thing then I reckon the engine would not be performing normally as it is.

[panasonic]

Oh boy pano, don't say that man. She's my baby and runs like a screaming beast. No doubt she's up there in age, but been very well maintained throughout.

Just pulling your chain Jason. probably nothing serious...something vibrated loose. Can be hard to track down sometimes though. I am sure you will find it.

[pstephens46]

Good point on running in water. 2 strokes make a lot of racket out of water. Heard one from about 1/2 mile away last night

[rodbolt17]

boys
I cant say much cause someone wont post the model number.

[99yam40]

Thought my signature with engine ID was being shown. Guess not. Thanks for reminding me. The rattle is so faint that when the engine is running it's drowning out the rattle, making it difficult to locate. I only spent a few minutes searching the first go around. Will spend more time tomorrow.

As far as if I'm 100% it's external...well I guess I can't be 100%. However, in my mind if it's an internal thing then I reckon the engine would not be performing normally as it is.

Shame on you for knowing you did not post what motor you have and still keep it a secrete.

Just because it runs well does not mean it cannot be internal noise.

I had a whining noise that kept getting worse year after year.

When I finally tore MY C40 apart ,I found 3 of the 4 main bearings (ball bearing type)had pits.
Had to send off the crank to have it rebuilt.
buying used motors can be a pain some times.