Mercruiser 260 Pre-Alpha Lower unit part

[ezez]

Again, I purchase a project boat and going through a few things.

I pulled the lower unit on my Pre-Alpha Mercruiser to replace the impeller/water pump. When I pulled the lower unit down and out of the drive shaft housing this part came down with it. I can't find the part on any schematics. What is it?

It is a couple inches wide, feels like rubber w/ metal plate.

Other side:

 

[Fishermark]

Re: Mercruiser 260 Pre-Alpha Lower unit part

That's the remains of your exhaust shutter.

 

[ezez]

Re: Mercruiser 260 Pre-Alpha Lower unit part

That's the remains of your exhaust shutter.

The exhaust shutters are located where? And are responsible for what?

My guess is near the exhaust riser/elbows and that they prevent water from entering into the block in case of backfire etc.

Thanks in advance!

 

[Bt Doctur]

Re: Mercruiser 260 Pre-Alpha Lower unit part

http://www.boatfix.com/merc/Servmanl/16/16D7R2.PDF

 

[ezez]

Re: Mercruiser 260 Pre-Alpha Lower unit part

Thanks!

 

[Fishermark]

Re: Mercruiser 260 Pre-Alpha Lower unit part

My guess is near the exhaust riser/elbows and that they prevent water from entering into the block

Correct on both counts.

 

[ezez]

Re: Mercruiser 260 Pre-Alpha Lower unit part

Alright, this looks like a huge PITA to replace these. I have the Service Manual in hand and it looks like pulling the motor is a real possibility when replacing these things. Any tricks from you experienced boat grease monkeys.

I'll have to see if I can get an allen wrench down to the screws that attach the elbows to the separator. If I can get to them it shouldn't be too bad but I'm not real sure if I have the space to.

 

[Bt Doctur]

Re: Mercruiser 260 Pre-Alpha Lower unit part

drain the manifolds/risers and remove the risers.remove exaust dumps and lower rubber coupling. Thats where the shutters go. page 7D-2
remove items A,B,C

 

[ezez]

Re: Mercruiser 260 Pre-Alpha Lower unit part

drain the manifolds/risers and remove the risers.remove exaust dumps and lower rubber coupling. Thats where the shutters go. page 7D-2
remove items A,B,C

I saw that in the manual linked but in the actual Service Manual they look like they are located at the bottom of the exhaust elbows at the "T". Which is it on a MCM260?

 

[ezez]

Re: Mercruiser 260 Pre-Alpha Lower unit part

Oh, that's not an exhaust shutter that I am seeing in the SM... that is the water shutter, correct?

Thanks again!

 

[Bt Doctur]

Re: Mercruiser 260 Pre-Alpha Lower unit part

Nope, just under the rubber couplings in this pic.

 

[ezez]

Re: Mercruiser 260 Pre-Alpha Lower unit part

Nope, just under the rubber couplings in this pic.

Alright, I know it has been 6 months but in the North we have winters. I'm sorry the pictures are expired but they were of the remnants of an exhaust shutter.

I finally got around to pulling the elbows to replace the exhaust shutters and they are NOT at the top of the wye just under the rubber couplings. Like I initially thought they are below at the T-pipe junction. So, the manual says that removing the engine is the way to have them replaced.

I'm not sure I'm up for that so, I'm looking for any advice. Like a repair that doesn't require removing the engine. Has anyone just not replaced them? I know water intrusion is a possibility but realistically how likely is that?

Pulling my hair out at this point.

 

[dubs283]

Re: Mercruiser 260 Pre-Alpha Lower unit part

pull the engine

remove the y-pipe at the transom plate

install new water shutter

or...

know your limits, do not suddenly decrease speed coming off plane, and never face the transom into heavy waves

 

[Pete104]

Re: Mercruiser 260 Pre-Alpha Lower unit part

Stop pulling your hair out & pull the engine instead! It's not that bad!!! Due so with caution, the components of those "exhaust tubes" are becoming harder & harder to come by.

 

[Bondo]

Re: Mercruiser 260 Pre-Alpha Lower unit part

I know water intrusion is a possibility but realistically how likely is that?

Ayuh,... How "Stern Heavy" does yer boat sit in the water,..??

 

[ezez]

Re: Mercruiser 260 Pre-Alpha Lower unit part

Ayuh,... How "Stern Heavy" does yer boat sit in the water,..??

LOL well it is a "new" boat to me and I haven't put it in the water so, I really don't know. This was bought from an elderly family member late last fall. They had let the boat sit for several years after their spouse died. I bought it partly to help them out and secondly as a a project boat. The price I paid was such that I could either work on it, part it out or sell it. In any of those cases I would make out alright.

I knew that I would be in for some surprises due to how long it sat but I'm not real sure I want to get involved at the level of pulling an engine. I'm not someone who is scared of turning a wrench, I've rebuilt outboards, restored cars and motorcycles etc. but I'm not sure THIS boat is something I want to get too involved in.

 

[Bondo]

Re: Mercruiser 260 Pre-Alpha Lower unit part

but I'm not sure THIS boat is something I want to get too involved in.

Ayuh,... She IS an Ole barge,... That don't make her Bad though...
If it ain't a rotten hull, she's a pretty Sweet lookin' ole girl...

If ya ain't scared of Wrenches,...
Boat motors are Waaayyy easier to pull than Any of the others you mention...
Well, cars anyway...

 

[ezez]

Re: Mercruiser 260 Pre-Alpha Lower unit part

Well, I've spoken to a few knowledgeable folks, debating the possibilities and the risks. I've decided to throw it back together, put it in the water and run it to see how the boat performs. Since, I don't really know what I have I need to throw it in the water to see if it is worth all the work involved to replace the exhaust shutters. The truth is that this thing might have a lot more issues and I have to go out and see what it does prior to investing in all that work.

From what I have been told if it does end up sucking water in, it will probably just lead to hydrostatic lock which I can work through fairly easily.

I appreciate the feedback. Please wish me luck.

 

[Fishermark]

Re: Mercruiser 260 Pre-Alpha Lower unit part

From what I have been told if it does end up sucking water in, it will probably just lead to hydrostatic lock which I can work through fairly easily.

I don't think you will have any issues without the shutters. The past several Mercruisers I have owned have not had the shutters, and I have had no issues.

But when you say just lead to hydrostatic lock. I don't know that I would say that is a small matter. Sure, easy to take care of if nothing bends or breaks.... but that is a BIG "IF." Just sayin....

 

[ezez]

Re: Mercruiser 260 Pre-Alpha Lower unit part

I don't think you will have any issues without the shutters. The past several Mercruisers I have owned have not had the shutters, and I have had no issues.

But when you say just lead to hydrostatic lock. I don't know that I would say that is a small matter. Sure, easy to take care of if nothing bends or breaks.... but that is a BIG "IF." Just sayin....

That is why I said "probably just lead to hydrostatic lock" in the post. I understand that there is risk of damage. Again, after consulting with a few folks I think that the risk of intrusion is fairly small if care is taken. If intrusion does occur in all likelihood hydrostatic lock will be the outcome. I understand that if intrusion does happen and leads to hydrostatic lock, it is possible that there could be much more serious damage to the engine.