Bad Shimmy

[dshirack]

Hello all,

After doing a complete overhaul on the interior I finally got my '84 Bayliner Capri on the water yesterday. It has a pretty bad shimmy at all speeds. I had it at about 4000 rpms for a few seconds and started hearing a "whine." I opened the engine compartment to see black smoke. Volvo Penta 4cyl, 270 sterndrive, 1 bbl carb. Motor temp never went above 180, oil pressure was always between 35-40. Sterndrive oil level was perfect and clean. After the "whining" we went back to the boat ramp at about 2000 rpms with no problems (still the shimmy, though).This trip was over two miles. I'm thinking U-Joints are shot, but I was wanting advice. Any and all accepted. Thanks.

Edit: I already have the Seloc Manual for this motor and sterndrive.

 

[Don S]

Re: Bad Shimmy

Edit: I already have the Seloc Manual for this motor and sterndrive.

That's good, everone needs a good knee pad when working on their engine. Might want to head up to the adults only thread and download an OEM manual. One for your engine and one for your drive.

What was the black smoke from? Exhaust leak?? Any belt dust from a locked up tentioner or pulley or ???

Have you looked at the prop? Any rope wrapped around it?

 

[dshirack]

Re: Bad Shimmy

I'm not sure what the smoke was from, as it cleared really fast when I opened the compartment. It smelled "oily." Like I said, after that incident it ran fine the whole way back (except for the shimmy). Once I got it out, the prop looked fine, nothing tangled in it, spun freely by hand. I already have the OEM manual downloaded as well (forgot to put in edit ). Thanks!

 

[Don S]

Re: Bad Shimmy

It may very well be the ujoints. If water has been in the bellows, they could be shot.
When was the last time the bellows was changed?

 

[littlebookworm]

Re: Bad Shimmy

When you had the outdrive off (I'm assuming you did), did you check engine alignment? If it's off, that would put a strain on the coupler and the universal and everything else back there. That would explain the smoke and the shimmy. Unfortunately, that might also mean that the coupler and/or universal are going or gone. I know of no way to check that short of hauling the boat and pulling the drive. Then the alignment, coupler and universal can be checked. I hope I'm wrong; but I don't think so. Sorry. Hy

 

[Don S]

Re: Bad Shimmy

When you had the outdrive off (I'm assuming you did), did you check engine alignment?

He's got a 270 Volvo, you don't pull the drive, and there is no alignment check like the Mercs.

 

[dshirack]

Re: Bad Shimmy

It may very well be the ujoints. If water has been in the bellows, they could be shot.
When was the last time the bellows was changed?

Last year.

 

[dshirack]

Re: Bad Shimmy

Bump.

 

[captmello]

Re: Bad Shimmy

So, did you pull the upper and check the ujoints?

 

[dshirack]

Re: Bad Shimmy

So, did you pull the upper and check the ujoints?

Unfortunately I haven't had time. My nine month old son keeps me just busy enough that I can't sneak out to work on the boat. I'm going to try this weekend when the misses can keep an eye on him while I take a gander at the u-joints. I bumped the thread to see if anyone had any other suggestions as to what could be wrong. Thanks everyone!

 

[captmello]

Re: Bad Shimmy

Well, I'm not sure what a shimmy is. Vibration? usually with ujoints, they will act up more when turning, change their tone a bit. Did you notice this? What about the prop? If its bent, it will cause vibrations.

 

[dshirack]

Re: Bad Shimmy

Well, I'm not sure what a shimmy is. Vibration? usually with ujoints, they will act up more when turning, change their tone a bit. Did you notice this? What about the prop? If its bent, it will cause vibrations.

A bad vibration. Sometimes though, it goes away for no reason, just driving straight ahead. When turning sharp, even at low speeds, I hear a knocking. Prop is brand new. No bends, nothing caught or wrapped around shaft.

Thanks!

 

[Don S]

Re: Bad Shimmy

Sometimes though, it goes away for no reason, just driving straight ahead. When turning sharp, even at low speeds, I hear a knocking.

Either your ujoints are shot, or the bearings in the flywheel housing are.

You need to pull the upper gear box and check the ujoints. Also check the shaft in the flywheel cover the ujoints spline onto. If there is ANY play up and down, you need to pull the engine and replace the bearings.

 

[dshirack]

Re: Bad Shimmy

You need to pull the upper gear box and check the ujoints. Also check the shaft in the flywheel cover the ujoints spline onto. If there is ANY play up and down, you need to pull the engine and replace the bearings.

I'll do that this weekend. Thanks for your help!