Water in Riser

[dozerII]

Need some opinions from the pros again. Picked up a StarCraft SS18 for next to nothing in the fall. It has 140 ser# 5962858 Engine has not run for 4 or more years. It was fogged and winterized by the last owner prior to putting it away. When I got it home I pulled the out drive and checked the motor over, hooked up a remote gas can and put a hose in the bell housing for cooling. Fired it up, it ran great. I then drained the water out of the block and the manifold and put her in the heated shop.
About a month later we pulled the plugs and did a compression test on it, 125 on 3 cyls. and 105 on # 3. The plugs showed no signs of rust and there is no water in the oil. Today I pulled the carb, manifold and exhaust elbow to replace the shutters. The Elbow had about a cup of water in it and there is a little bit of rust on the two rear ports in the head. The block has been cracked and has been welded!! The elbow is showing what looks to be a fairly bad crack . Pictures









Need some advice to go from here, the elbow I think is shot, Should I just replace it and try it? Suggestions.

Thanks

 

[Bondo]

Ayuh,.... That riser's scrap,.... Did ya drain the brass cap/ plug seen in the next to the last picture,..??

If not, that's where those ole style risers freeze, 'n bust,...

Show a picture of the manifold, at the manifold/ riser gasket surface,....
What little that can be seen of the riser's surface, don't look so good,...

 

[dozerII]

Thanks Bondo I will take a couple more pics and post them.

 

[dozerII]

Here are the pictures of the elbow and manifold surfaces, gaskets are still there.





Here is a better pic of the welded crack in the block, I'm pretty sure the manifold was replaced at the time the welding was done.

 

[HT32BSX115]

Howdy Glen and Bill!!

Happy New Year!

Engine has not run for 4 or more years. It was fogged and winterized by the last owner prior to putting it away.

It's particularly bad when you get water leaking from a cracked riser/manifold or leaking gasket. The water runs right into an open exhaust valve and sits in the cyl until you run it months (or years) later!

The plugs showed no signs of rust and there is no water in the oil.

It's usually not a lot of water.....

The Elbow had about a cup of water in it and there is a little bit of rust on the two rear ports in the head.

that's what was left of the water that didn't run into the cyl.....

The block has been cracked and has been welded!! The elbow is showing what looks to be a fairly bad crack . Need some advice to go from here, the elbow I think is shot, Should I just replace it and try it? Suggestions.

Yes. The elbow is "toast" the manifold may be OK. I think you need to pull the head and inspect the cyl and valves for (possibly) severe corrosion.

The welded block may or may not hold. If it was just cracked on the outside, you may be ok. It will likely crack again (backyard welded blocks always do) but if it's on the outside, it'll just drip (or "spew" )water on the outside.....Maybe you ought'a get a good bilge pump!!

OTOH, if it's ALSO cracked on the inside (and they frequently do) , it will leak water into the oil and there'll be nothing you can do about it (except replace the block)


Best Regards,


Rick

 

[keith2k455]

I think this is a math question. Welding castings is a pretty thorough debate, some swear it can be done and others will not touch them. I can say that none of your heavy equipment manufacturers allow welded castings for the reason that they may fail. I do believe automotive do allow welds on castings in certain specific locations of the casting.

All this said, what will the parts (minus block) cost to replace? What if you did all that then the weld went - would you replace the block or scrap the boat? If you'd keep the boat, you're just spreading your cost over time.

 

[dozerII]

Tomorrow I will take a look in the cylinders with a bore scope, to see what they look like and report back. Thanks for the comments so far.

 

[fishrdan]

Fill the manifold's water jacket with acetone to see if it leaks, or holds steady. (Acetone will leak through a crack that water won't.)

Agree that the riser is junk.

The valve seats may be leaking a bit due to the rust present. Was the compression test performed after the engine was run a bit, or after it's 4 year hiatus?

Those green gaskets are junk, I throw them away. Try to use the metallic/gray/metalized gaskets for the riser and manifold.

 

[dozerII]

Thanks Rick, Keith and Fishrdan. I agree the elbow is toast, I ordered one from iboats last night. I cleaned up the welded area on the block this morning and it looks like it was welded with nickel rod, there are no signs of rust anywhere around it. I looked in all 4 cylinder with my scope and found no rust. pics.

#4


#3


#2


#1


And a picture in the #3 exhaust valve.



I have no idea how long the motor has been run with the welded block, and like I said there is no sign of water in the oil. I have two Mercruiser 120's and they don't have the drain in the elbow like this one has. I'm thinking what has happened is, after we ran it back in the fall I drained the block and manifold and not the elbow and over the last two months the water has leaked through the crack in the elbow into the exhaust. Does this sound plausible? I don't have any acetone and can't buy it locally but I do have 5 gallons of Methyl Hydrate will this work to check the manifold? I put a little bit of ATF in on top of all the valves and rotated the motor over three or four revolutions. The rust that is in the intake and exhaust ports in the head is very light and just wiped off with a towel.
So I think the plan is to check the manifold install a new riser/elbow, shutters and try it for the summer to see if the block leaks, what are your valued opinions?

Thanks again

 

[keith2k455]

Glen, I'm going to have to tap out on your specific problem since I'm not knowledgeable on your setup. I do agree with running the block as long as it holds since you're in it for the long haul. Best of luck.

 

[dozerII]

Thanks Keith:thumb:

 

[dozerII]

A little more info, I just did a compression test, I let the gauge sit for 5 minutes with pressure to see if it would hold and this is the results.

#1 150psi
#2 160psi
#3 150psi
#4 165psi.

So I was little confused about the extra drain on the elbow on the 140 and had to check my 120, it is a 1978 and it has no plug in the spot the 140 elbow does, how does it drain?

 

[fishrdan]

Methly hydrate, never heard of it, it might work though. Water has the property of surface tension, so it could give a false test by bridging a small crack. If you put a drop of methyl hydrate on a hard surface (glass-plastic) does it bead up like water or spread out in a thin layer. Beading is surface tension.

My 73 140 HP has the riser side drain, not sure how a 120 riser without the side fitting would drain, probably a different design that doesn't need to be drained since the fitting isn't there.

 

[dozerII]

Methly hydrate, never heard of it, it might work though. Water has the property of surface tension, so it could give a false test by bridging a small crack. If you put a drop of methyl hydrate on a hard surface (glass-plastic) does it bead up like water or spread out in a thin layer. Beading is surface tension.

My 73 140 HP has the riser side drain, not sure how a 120 riser without the side fitting would drain, probably a different design that doesn't need to be drained since the fitting isn't there.

Thanks for the reply Dan, Methyl Hydrate is wood alchohol (gas line antifreeze) no beading or surface tension from it. I have searched for replacement elbows and the same part number replaces all 140's and 120's 76351A1 so I guess when the new one gets here I will see if it has a drain or traps water.

 

[fishrdan]

I let the gauge sit for 5 minutes with pressure to see if it would hold and this is the results.

#1 150psi
#2 160psi
#3 150psi
#4 165psi.

Is the gauge holding the pressure? I wouldn't think the cylinder would hold that PSI for 5 minutes. Also, was that a wet test or dry, I saw that you mentioned putting ATF on/in the valves.

Sounds like the methyl hydrate should work fine for manifold testing. Block/balance it, fill up the water jacket, look for leakage in the exhaust/intake ports, then let it sit for a couple hours to see if the fluid level drops.

 

[dozerII]

Is the gauge holding the pressure? I wouldn't think the cylinder would hold that PSI for 5 minutes. Also, was that a wet test or dry, I saw that you mentioned putting ATF on/in the valves.

Sounds like the methyl hydrate should work fine for manifold testing. Block/balance it, fill up the water jacket, look for leakage in the exhaust/intake ports, then let it sit for a couple hours to see if the fluid level drops.

The pressure dropped slightly over the 5 minutes, and yes it was with the little bit of ATF I put in on top of the valves.

 

[dozerII]

So I filled the water jacket in the manifold right to the top on Sunday morning and by afternoon it was down a 1/4" but there was nothing in the intake or exhaust area. So I thought it had evaporated cuz M/H does that quick. So I then topped it off again and tapped over any place the M/H was open to the air and left it till yesterday morning, again it was down 1/4". So I topped it off and sealed up all the manifold openings. This morning it was down 1/4" again but there was a puddle of M/H in the intake, so I guess the manifold has an internal crack. The reason I'm using Methyl Hydrate is I have lots on hand and it is cheap in comparison to Acetone which is $25.00 a gallon a little to expensive to throw out.

 

[fishrdan]

This morning it was down 1/4" again but there was a puddle of M/H in the intake, so I guess the manifold has an internal crack.

Sounds cracked to me. Sucks that it needs to be replaced, but good thing you caught it. You could pressure test it and squirt some soapy water on the suspect area to see if it bubbles up,,, if in doubt. But it sounds cracked to me.

 

[dozerII]

Sounds cracked to me. Sucks that it needs to be replaced, but good thing you caught it. You could pressure test it and squirt some soapy water on the suspect area to see if it bubbles up,,, if in doubt. But it sounds cracked to me.

Thanks for the reply Dan, now to try and find a decent deal on one with our crappy Canadian Dollar

 

[fishrdan]

Yeah, that's not going to be cheap, especially up there. I found one by searching with the Barr P/N and was able to get one on clearance. (You don't want to know how much.)