4.3 exhaust shutter replacement question

[ckaiser]

Recent purchase 98 Excel 175 SX. Mercruiser 4.3 with the one-piece manifolds. Found shutter parts in the exhaust; torn bellows, pieces in the outdrive when I took it off to service it.
I'd like to replace the shutters. If I found pieces of one, I might soon have pieces of the other. Rather not replace the exhaust boot twice.

So my question is this. I'm working on the engine and have taken the boot screws loose and used a probe to unseal the boot from the manifold and the y-pipe. But the boot isn't moving. I was hoping I could slide it down and get to the shutters that way but it doesn't look real hopeful.

This isn't the type with the elbows; it's the one-piece similar to this:
http://i-netmarine.com/manifolds/mercruiser_43l_v6_chevy_1_pc.htm

Is it possible to get the boots and shutters off without removing the manifold or y-pipe?

Thanks!

 

[Don S]

Re: 4.3 exhaust shutter replacement question

Is it possible to get the boots and shutters off without removing the manifold or y-pipe?

you don't have to remove the Y pipe, but you do have to remove the manifolds with that type manifold.

 

[dg512055]

Re: 4.3 exhaust shutter replacement question

The best thing to do is go ahead and pull the manifolds. It is not that hard, but they are HEAVY. I have had mine off and inspected them. I also stripped and repainted them over last winter. My shutters were toast also. I just left them out altogether. I have had no problems all last summer. Be sure to re-torque the manifold bolts after running the boat the first few times.

 

[pwpns]

Re: 4.3 exhaust shutter replacement question

I had to replace the shutters on my 99 stingray 192 with a 4.3 with one piece manifolds I was able to pull the boots up on the exhaust manifolds far enough to get the shutters in the Y pipe. I had to work with them some and put alot of elbow grease in them to get them to move up but I did it. Good luck.

 

[ckaiser]

Re: 4.3 exhaust shutter replacement question

It's starting to look like removing the manifolds will be the best way to do this. Probably less chance of tearing a boot, too. Plus I can look behind the engine while I have them off.

Any issues with bolts rusting or snapping? The manifold gasket looks like there's no water passage through there, so I'm guessing it's not a big deal...

Thanks!

Charlie

 

[ckaiser]

Re: 4.3 exhaust shutter replacement question

Just finished removing the manifolds. Pretty simple task.

I already had the doghouse removed, as in unscrewed from the floor and off the boat. I pulled the side panels that it closes to for better access (3 screws per side). Battery already out for some other work.

Next step was pull the spark plugs, because those big heavy manifolds will drop onto them when you unbolt them (good tip from a friend). Unbolted the throttle/shift linkage bracket from the starboard manifold. Disconnected the ignition module connectors from the port side.

Drained the manifolds and disconnected the water hoses. Loosened all the boot clamps and slid them out of the way. Double checked that nothing else was going to have to come off; didn't want to be holding a 50 lb+ manifold trying to disconnect something...

Undid all the bolts a turn or so to make sure nothing was stuck; everything OK. Pulled all the bolts except the second one from the front. Then got hold of the manifold and removed the last bolt. The manifold did drop down a bit but was held nicely by the boot. Got positioned properly and lifted it up and out. Repeated on the other side.

Found shutter parts in both down tubes. Good call to get them out of there. The port side was wedged in and probably blocking flow to a significant degree. Got all that out of there. I'll be checking with a helper later to make sure there's nothing left in there.

I can tell that this engine has been out previously. No clue why, but I can tell you that if the installer worked for me (I ran auto repair shops for many years) he would have been fired. No thought to proper routing of components, spark plug wires not in their looms, hoses against manifolds, etc. Just a sloppy job. That will all change...
It will also segue into my next post, but it will be a different thread.

Definitely worth pulling the manifolds. I can see all the stuff behind the engine now and it will make doing other things much easier.

Thanks for the help. I hope my description will assist someone else...

Charlie