91' larson, 4.3 timing issue

[thegoat86]

4.3 vortec internal balancer blues

My boat still has the factory fluid motor mounts. As I am learning the first gen vortec motors did not have the internal balancing and relied on the fluid mounts to take up motor vibration.

Cant I disconnect the internal balancer and rely on the fluid mounts to do the same job they would have originally?

 

[dannys2004glastron175mx]

I would pull the intake and have a look . you should be able to see what its hitting . maybe some one left a wrench or 2 in there :facepalm: :laugh:

 

[Scott Danforth]

why not pull the cover and replace the gears? the noise comes from slop in the gears. Noise is considered "normal" Refer to GM TSB #00-06-01-023

 

[thegoat86]

The gears were not loose. That was the first thing I looked for. I did preventively change the timing chain while I was in there. The balancer is knocking internally. I would have heard the gear noise when I started the motor with the timing chain cover off. (I thought it might be the chain stretched) I was one foot from the engine front. I did feel it further in the engine when I put my hand on the intake and carb. I don't care anymore really. This has been an uphill fight from the start. I wont be buying another boat with the 4.3.

Either I disconnect it (which I am trying to get the answer) or I insulate the doghouse and run er' til' she dies. This is all so odd because the block looks brand new upon inspection. (I did read the bulletin, but believe the problem to be elsewhere)

 

[thegoat86]

So, I opted to just insulate the doghouse for the noise. There is really no need to pull the balancer and make any unnecessary changes to the motor. This is a common issue with the 4.3. hope this post helps people out. Good luck and nice boating.

 

[Bondo]

The gears were not loose. That was the first thing I looked for. I did preventively change the timing chain while I was in there. The balancer is knocking internally. I would have heard the gear noise when I started the motor with the timing chain cover off. (I thought it might be the chain stretched) I was one foot from the engine front. I did feel it further in the engine when I put my hand on the intake and carb. I don't care anymore really. This has been an uphill fight from the start. I wont be buying another boat with the 4.3.

Either I disconnect it (which I am trying to get the answer) or I insulate the doghouse and run er' til' she dies. This is all so odd because the block looks brand new upon inspection. (I did read the bulletin, but believe the problem to be elsewhere)

Ayuh,.... That balancer shaft rides in bearin's, just like the crankshaft bearin's,....

If it's knockin', ya oughta pull the intake, 'n See which bearin' is goin', or whether the bearin's were installed properly,....

You can expect a motor life of minutes, rather than 1000s of hours,.....

I've got the same motor, with 2,000 problem free hours on it,....

 

[thegoat86]

In process of removing intake.... will inform later.

 

[thegoat86]

Sooooo.... I have the motor running like a top. Timed dead on. Nice smooth idle, revs nice in the driveway, starts by just bumping the key. No smoke or haze. So, I decided to take it out for the day. I have zero power under load. It seems as if the ignition may not be advancing the timing. If I rev it slowly and be patient, I can get it up to speed and on plane. And it goes great. But if I jump the throttle or gun it, It stalls.

I got home, rechecked timing. Dead on. Checked all of my plugs, wires, coil, ect. I know the thunderbolt module is working because the motor runs. And it still revs right up in the driveway not under load. Bad module? When the motor ran badly it still had gobs of torque under load. Just ran poorly.

 

[Bondo]

Ayuh,.... Check the fuel filter for water, 'n crud,...

What happened to the Knockin',..??

 

[bruceb58]

It seems as if the ignition may not be advancing the timing.

That's easy to check with a timing light.

 

[thegoat86]

Knocking settled down. Insulated the doghouse. Tolerable. Just changed water + fuel filter. Will change again. Going to check the timing under load to see if its advancing. It should advance if i just rev it in the driveway i would assume. Had it with this one though. Buying a newer boat tomorrow. Making this one my fishing only boat.

 

[bruceb58]

Yes, you can check it in your driveway.

 

[thegoat86]

. Going to check the timing under load to see if its advancing. It should advance if i just rev it in the driveway i would assume. .

It didn't look like it but that was a question....

 

[bruceb58]

It didn't look like it but that was a question....

And I answered it in my last post.

 

[thegoat86]

Gracious punkin' cheers:watermelon:

 

[Rick's Welding Service]

I have both , one with the balance shaft and one older without one , as for the timing the 4.3 may need an adjustment on the rockers something that I found in a GM recall the dealership uses a machine and it baffled me that they even used this motor on anything , the Volvo 4.3 ?? although the same may not be as lost as the gm. It's one cylinder the other 5 are usually timed right , this thing is a joke. It's known as the bastard child. ??

 

[Bondo]

Ayuh,..... Welcome Aboard Rick,....

We don't post comments on threads older than 90 days here at iboats,....
It causes waayyy to much confusion,....

I'm gonna close this one, 'n let it sink back into the archives,...