After paying a mechanic three hundred bucks to check out our overheating problem (and he finding nothing), I decided to take a look myself. After asking around and reading here I was pretty sure it would be the exhaust elbow, so this weekend I spent Sunday at the dock and on the engine. Sure enough, after unsrewing (a 2 minute job) the small elbow I could see that it only had the tiniest hole left open. I don't even know how it as passing *any* water! So I took the whole exhaust elbow off and gave it a good clean up. BTW, while I was at it I changed both the oils using one of those "Oil Boy" vacuum pumps - I highly recommend it, very easy, no mess. Unfotunately it looks like our stuffing box has started to drip at least once a second, too much for my liking. Is it sufficient to get a big wrench and tighten it?
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M
Miles
Probably need two big wrenches...
One to hold the nut and one for the lock nut. Two big channel locks would work or you can get an official packing box wrench for about $20. Assuming you still have some adjustment room left it's real easy. Next time you haul out you might think about replacing the stuffing with the teflon type that's dripless, nice to have a dry bilge... Glad you fixed the overheating problem!
One to hold the nut and one for the lock nut. Two big channel locks would work or you can get an official packing box wrench for about $20. Assuming you still have some adjustment room left it's real easy. Next time you haul out you might think about replacing the stuffing with the teflon type that's dripless, nice to have a dry bilge... Glad you fixed the overheating problem!
R
R DEUTSCH
dry bilge
I dont think I have ever seen a dry bilge,my boat is a 99 and the day it was new there was water in the bilge,condensation alone causes wet bilge and packing glands are supposed to leak a little
I dont think I have ever seen a dry bilge,my boat is a 99 and the day it was new there was water in the bilge,condensation alone causes wet bilge and packing glands are supposed to leak a little
M
Miles
The dripless stuff really works...
You're right about the condensation, but the dripless stuff keeps the seawater from the packing gland out very well. Cleaning the knotmeter impeller lets in a little seawater, the shower drains to the bilge and that puts in a lot when we use it. But between the bilge pump and my trusty turkey baster it's pretty dry! Not that I'd want to eat off it or anything...
You're right about the condensation, but the dripless stuff keeps the seawater from the packing gland out very well. Cleaning the knotmeter impeller lets in a little seawater, the shower drains to the bilge and that puts in a lot when we use it. But between the bilge pump and my trusty turkey baster it's pretty dry! Not that I'd want to eat off it or anything...
S
schaefer
surprised
that your yanmar even ran....as my exhaust elbow closed i got progressively more black exhaust out the back end....to the point where one cylinder shut down...i pulled my hair out thinking bad fuel..clogged injecter etc etc until a wise old mechanic named randazzo heard me mention black exhaust coming back out of the air filter...he pegged the blocked elbow and sure enough all has been well since cleaning it out....can you red line now without getting that black sooty exhaust???......p s r deutsch...are you a g u grad????
that your yanmar even ran....as my exhaust elbow closed i got progressively more black exhaust out the back end....to the point where one cylinder shut down...i pulled my hair out thinking bad fuel..clogged injecter etc etc until a wise old mechanic named randazzo heard me mention black exhaust coming back out of the air filter...he pegged the blocked elbow and sure enough all has been well since cleaning it out....can you red line now without getting that black sooty exhaust???......p s r deutsch...are you a g u grad????
J
Jon
Black smoke exhaust
Actually, now you mention it, yes I did get black smoke sometimes (when starting). That now seems to have gone. I still get a certain abount of white smoke, but nothing I'm worried about. I haven't taken the engine over 3000, it used to overhead if I ran above 2400 for any amount of time. I'm talking about the raw water channel in the elbow being blocked - did you clean the raw water channel too?
Actually, now you mention it, yes I did get black smoke sometimes (when starting). That now seems to have gone. I still get a certain abount of white smoke, but nothing I'm worried about. I haven't taken the engine over 3000, it used to overhead if I ran above 2400 for any amount of time. I'm talking about the raw water channel in the elbow being blocked - did you clean the raw water channel too?
D
Douglas
Cleaning caveat
Now that you know what your problem was, I would replace the mixing elbow. Serious engine damage can occur if the exaust/water channel breaches. And if it was corroded enough to clog it could have deteriorated to the point of passage failure. You have the experience of removal and installation on your side now. The mixing elbow is cheap compared to an engine. -Doug s/v BRENDA GAIL
Now that you know what your problem was, I would replace the mixing elbow. Serious engine damage can occur if the exaust/water channel breaches. And if it was corroded enough to clog it could have deteriorated to the point of passage failure. You have the experience of removal and installation on your side now. The mixing elbow is cheap compared to an engine. -Doug s/v BRENDA GAIL
T
Tim Schaaf
every four or five years
for what it is worth, I find I have to regularly change the elbow every four to five years. I plan on it, and actually always carry a spare. It is not expensive. By the way, the same is true for some of the Yanmar raw water pumps. On my 2QM15, for example, the life of the pump is also a rather predictable five to six years. This is quite apart from regular maintenance such as changing impellers, wear plates, and cams. I plan on this, too. However, the pump is NOT cheap, at all.
for what it is worth, I find I have to regularly change the elbow every four to five years. I plan on it, and actually always carry a spare. It is not expensive. By the way, the same is true for some of the Yanmar raw water pumps. On my 2QM15, for example, the life of the pump is also a rather predictable five to six years. This is quite apart from regular maintenance such as changing impellers, wear plates, and cams. I plan on this, too. However, the pump is NOT cheap, at all.
G
Gene B. s/v Paradigm
Dripless Seals are Great!
I installed a PSI dripless seal last year and have had not one drop since! Plus, it puts less friction on the shaft, so there is less load on the engine. Highly recommended. Plenty of endorsements and discussion in the archives.
I installed a PSI dripless seal last year and have had not one drop since! Plus, it puts less friction on the shaft, so there is less load on the engine. Highly recommended. Plenty of endorsements and discussion in the archives.
J
Jon
Darn thing overheated again...
Well, I know that the exhaust elbow would have helped, but just this weekend we had several overheats and barely limped back to port. Well, silly me I spent Sunday stripping down every single part of the colling system I could think of - everything! (Hey, at least I know the engine now) It all checked out AOK. So then I went back to the raw water inlet and checked again. This time I saw that there was a small piece of seaweed hanging down. I pulled on it and the small piece became a large piece. After disconnecting the hose and blowing on the through hull it cleared it right out. Raw water flow was greatly increased. The question I now have is - shouldn't there be a strainer on the outside of the through hull. Or is it normal not to have one. Surely this would allow really large pieces of debris to be sucked up!
Well, I know that the exhaust elbow would have helped, but just this weekend we had several overheats and barely limped back to port. Well, silly me I spent Sunday stripping down every single part of the colling system I could think of - everything! (Hey, at least I know the engine now) It all checked out AOK. So then I went back to the raw water inlet and checked again. This time I saw that there was a small piece of seaweed hanging down. I pulled on it and the small piece became a large piece. After disconnecting the hose and blowing on the through hull it cleared it right out. Raw water flow was greatly increased. The question I now have is - shouldn't there be a strainer on the outside of the through hull. Or is it normal not to have one. Surely this would allow really large pieces of debris to be sucked up!
Not a good IDEA!
Jon: The problem with a strainer on the outside is that you cannot clear it. With an open thru hull you can clean the strainer or pull the hose off an push something off the thru hull with a stiff wire or a dowel rod. Check out the archives, there has been some discussion on this issue.
Jon: The problem with a strainer on the outside is that you cannot clear it. With an open thru hull you can clean the strainer or pull the hose off an push something off the thru hull with a stiff wire or a dowel rod. Check out the archives, there has been some discussion on this issue.
D
David
Hull strainer
Almost every boat I survey has a hull strainer mounted on the outside. On sailboats they are usually mounted so the strainer grill faces aft. They help cut down seaweed, rockweed and eel grass injestion while still providing good water flow.
Almost every boat I survey has a hull strainer mounted on the outside. On sailboats they are usually mounted so the strainer grill faces aft. They help cut down seaweed, rockweed and eel grass injestion while still providing good water flow.
D
Dan Geltmacher
nigal calder
Buy a copy of Nigal Calder's "Be your own diesel mech" book. This forum is great but that book has saved me plenty of mula and time... You can rebuild your raw water pump for a fraction of what a new one is... I'm not smart (a jarhead)and I did it. Illusions Dan
Buy a copy of Nigal Calder's "Be your own diesel mech" book. This forum is great but that book has saved me plenty of mula and time... You can rebuild your raw water pump for a fraction of what a new one is... I'm not smart (a jarhead)and I did it. Illusions Dan
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