Help with vibration from 1400-3500 RPM

[skisky89]

I've got a vibration that I can hear (and feel...lol), sounds like 40hz or so...

This is on my 1995 Sea Ray 195BR, 4.3L Mercruiser Alpha1 gen 2

This vibration is new! I must have done something wrong during my maintenance.. but where do start to troubleshoot?

This winter I removed the outdrive, replaced the impeller, and replaced the gear lube in the drive. I also replaced the u-joints.
My gimbal bearing was shot, I replaced it and aligned the engine.
Also replaced the alternator, it quit working while on the ears during my pre-float test this spring.
I installed an exhaust bellow (prev bellow didn't clamp on the out-drive side)

Prop seems fine, I think the same vibration is still present if I rev it to 2k RPMS on the trailer in neutral (water muffs on.)

What could I have messed up? The engine alignment is pretty straight forward. Is there a wrong way to put the U-joints on the yolk to the outdrive?

Thanks!

 

[Scott06]

I've got a vibration that I can hear (and feel...lol), sounds like 40hz or so...

This is on my 1995 Sea Ray 195BR, 4.3L Mercruiser Alpha1 gen 2

This vibration is new! I must have done something wrong during my maintenance.. but where do start to troubleshoot?

This winter I removed the outdrive, replaced the impeller, and replaced the gear lube in the drive. I also replaced the u-joints.
My gimbal bearing was shot, I replaced it and aligned the engine.
Also replaced the alternator, it quit working while on the ears during my pre-float test this spring.
I installed an exhaust bellow (prev bellow didn't clamp on the out-drive side)

Prop seems fine, I think the same vibration is still present if I rev it to 2k RPMS on the trailer in neutral (water muffs on.)

What could I have messed up? The engine alignment is pretty straight forward. Is there a wrong way to put the U-joints on the yolk to the outdrive?

Thanks!

First thought pul drive recheck ujoints and gimbal bearing.
run it with drive off and see if vibration is still there , jam a house in bellousing water passage to supply cooling water

 

[tpenfield]

You could run the engine w/out the drive as stated to see if that makes a difference. Another thing I would check is the engine mounts. See if the lag bolts are loose.

 

[achris]

Replacing a gimbal bearing doesn't change the engine alignment. If the alignment was good with the old bearing, it doesn't change when a new bearing goes in. Did you need to adjust the alignment much?

Chris...

 

[skisky89]

You could run the engine w/out the drive as stated to see if that makes a difference. Another thing I would check is the engine mounts. See if the lag bolts are loose.

Thanks Guys! Will do, and will post back

 

[skisky89]

Replacing a gimbal bearing doesn't change the engine alignment. If the alignment was good with the old bearing, it doesn't change when a new bearing goes in. Did you need to adjust the alignment much?

Chris...

The end result was slight adjustment to the engine alignment. A bit higher on the front mounts

 

[achris]

The end result was slight adjustment to the engine alignment. A bit higher on the front mounts

Slight is ok, especially slightly up (the rubber in the mounts does compress very slightly over time with the load). A large change would be a concern.

 

[skisky89]

Back with more information!!

I started by removing the out-drive, I immediately:
- Checked engine alignment (front mounts could be adjusted up, maybe a half turn?) But nothing awful was going on there.
- New u-joints and old yolk looked fine
- Gimbal bearing was smooth
- Threw a hose in the water inlet for cooling, and started the engine

With the outdrive off, the vibration is still there! What in the world?!

Here are my troubleshooting thoughts, I should.... (ordered by priority)
- Pull and check/replace all the spark plugs (check for surprises)
-- Check cylinder compression if surprised
- Check/replace rotor and points
- Check/set the timing
- Seafoam the carb
- Replace engine mounts??

Maint. Info...
- About 1.5 years ago I rebuilt the carb and replaced the spark plugs
- Just put a new starter and alternator on it

It's important to mention that rain water sat in the boat for few weeks late fall 2021 (forgot to pull my plug.)
I checked my oil for water (there was none), had to replace the starter and gimbal bearing. It's beginning to look like I have other damage.... hopefully I just need a tune-up here.

How does my approach sound?
Is there anything I'm missing, am I headed in the right direction?

 

[nola mike]

Pulley out of line, harmonic balancer, dead cylinder/misfire come to mind.

 

[Scott06]

Back with more information!!

I started by removing the out-drive, I immediately:
- Checked engine alignment (front mounts could be adjusted up, maybe a half turn?) But nothing awful was going on there.
- New u-joints and old yolk looked fine
- Gimbal bearing was smooth
- Threw a hose in the water inlet for cooling, and started the engine

With the outdrive off, the vibration is still there! What in the world?!

Here are my troubleshooting thoughts, I should.... (ordered by priority)
- Pull and check/replace all the spark plugs (check for surprises)
-- Check cylinder compression if surprised
- Check/replace rotor and points
- Check/set the timing
- Seafoam the carb
- Replace engine mounts??

Maint. Info...
- About 1.5 years ago I rebuilt the carb and replaced the spark plugs
- Just put a new starter and alternator on it

It's important to mention that rain water sat in the boat for few weeks late fall 2021 (forgot to pull my plug.)
I checked my oil for water (there was none), had to replace the starter and gimbal bearing. It's beginning to look like I have other damage.... hopefully I just need a tune-up here.

How does my approach sound?
Is there anything I'm missing, am I headed in the right direction?

You have no points , but cap and rotor if not changed may have corrosion. I would do a cylinder drop test, pull plug wires off one at a time and see if idle quality changes.
verify timing. Would suspect ignition item got corroded over winter maybe a plugwire is dis connected

also being a 95 may have the older style ignition sensor in distributor with exposed wire connections on out side. Newer ones are sealed and have separate ground wire

 

[achris]

Yeah, my first thought is ignition. Make sure you have good spark to all cylinders. Make sure the plugs are good (IE new ones). I'd also look at putting new silicone leads in, and a new cap (thoroughly inspect the rotor). Also, as mentioned, check the distributor sensor. If it's the old style, replace it.

One trick I have used is to put a timing light on the coil to distributor HT lead. That lets you see all 8 sparks. If one's MIA is pretty easy to see....

Also mentioned and worth looking at, balancer...

Chris...

 

[achris]

...It's important to mention that rain water sat in the boat for few weeks late fall 2021 (forgot to pull my plug.)
I checked my oil for water (there was none), had to replace the starter and gimbal bearing. It's beginning to look like I have other damage.... hopefully I just need a tune-up here.

How does my approach sound?
Is there anything I'm missing, am I headed in the right direction?

Ok... Just reread... If water got that high I wonder if the flywheel has a rusted half that has thrown it out of balance?

Chris....

 

[skisky89]

Back with more information!!

I started by removing the out-drive, I immediately:
- Checked engine alignment (front mounts could be adjusted up, maybe a half turn?) But nothing awful was going on there.
- New u-joints and old yolk looked fine
- Threw a hose in the water inlet for cooling, and started the engine

With the outdrive off, the vibration is still there! What in the world?!

Here are my troubleshooting thoughts, I should.... (ordered by priority)
- Pull and check/replace all the spark plugs (check for surprises)
-- Check cylinder compression if surprised
- Check/replace rotor and points
- Check/set the timing
- Seafoam the carb
- Replace engine mounts??

Maint. Info...
- About 1.5 years ago I rebuilt the carb and replaced the spark plugs
- Just put a new starter and alternator on it

It's important to mention that rain water sat in the boat for few weeks late fall 2021 (forgot to pull my plug.)
I checked my oil for water (there was none), had to replace the starter and gimbal bearing. It's beginning to look like I have other damage.... hopefully I just need a tune-up here.

How does my approach sound?
Is there anything I'm missing, am I headed in the right direction?

V/R

Ok... Just reread... If water got that high I wonder if the flywheel has a rusted half that has thrown it out of balance?

Chris....

That's an excellent point! I'd need to pull the engine and bell housing for that, right?

I'll have to read up on the harmonic balancer.

Can I use and automotive cap ? Or is this another thing that should be marine rated?

 

[Bondo]

Can I use and automotive cap ? Or is this another thing that should be marine rated?

Ayuh,..... Welcome Aboard,..... There is no automotive cap for that distributor,.....
It's a Merc marine distributor,....
Automotive plug wires don't work either,..... too short,....

 

[skisky89]

Status:
Disconnected all pulley accessories, still vibration
Pulled all plugs, a few were wet but all looked OK
Pull cap and rotor, they were in awful condition
Distributor sensor is the new 'version'

Ordering:
Distributor Cap kit
Spark Plug wire set
Spark Plugs

 

[tank1949]

I've got a vibration that I can hear (and feel...lol), sounds like 40hz or so...

This is on my 1995 Sea Ray 195BR, 4.3L Mercruiser Alpha1 gen 2

This vibration is new! I must have done something wrong during my maintenance.. but where do start to troubleshoot?

This winter I removed the outdrive, replaced the impeller, and replaced the gear lube in the drive. I also replaced the u-joints.
My gimbal bearing was shot, I replaced it and aligned the engine.
Also replaced the alternator, it quit working while on the ears during my pre-float test this spring.
I installed an exhaust bellow (prev bellow didn't clamp on the out-drive side)

Prop seems fine, I think the same vibration is still present if I rev it to 2k RPMS on the trailer in neutral (water muffs on.)

What could I have messed up? The engine alignment is pretty straight forward. Is there a wrong way to put the U-joints on the yolk to the outdrive?

Thanks!

Recheck plugs and plug wires. Pull wires at night and look for fire leakage. It could be cracked plug wire leaking fire.

 

[skisky89]

Much smoother after replacing all of the electron pipes! More like 'normal' but there's still a little something there.
I'll know for sure this weekend.
Can anyone tell me if engine mounts 'go bad?'
They seem like something that could break or losen from the boat. But can they be 'bad' and contribute to vibration?

 

[achris]

Much smoother after replacing all of the electron pipes! More like 'normal' but there's still a little something there.
I'll know for sure this weekend.
Can anyone tell me if engine mounts 'go bad?'
They seem like something that could break or losen from the boat. But can they be 'bad' and contribute to vibration?

Yes, the rubber can deteriorate to the point of collapse. You'll see it when you check the engine alignment. And as you already have the drive off, now's a good time to check.

Chris........

 

[skisky89]

R

Yes, the rubber can deteriorate to the point of collapse. You'll see it when you check the engine alignment. And as you already have the drive off, now's a good time to check.

Chris........

Right on, front mounts are shot. Glad I asked! Couldn't even tell there was rubber....

 

[skisky89]

Yes, the rubber can deteriorate to the point of collapse. You'll see it when you check the engine alignment. And as you already have the drive off, now's a good time to check.

Chris........

Chris, it looks like you've already been dealt with engine mounts from a previous thread. The mounts I bought maybe not be tall enough... Am I screwed? I've put them in... They may not be tall enough for me to align the engine. Maybe I can put a pressure treated 1-by between them and the boat?