I want to put a three bladed prop on my 29.5 - the cruising speed seems low and I am dead in rough seas...what size and pitch of a prop do you recommend - where can I get one (I do NOT want to spend $2200 bucks for a folding max or anything like that)... Further - my engine seems to want to overheat at over 2600RPM... a guy told me the Yanmar engine in there is designed to run at full throttle 3300RPM without overheating...any ideas, suggestions or similar experiences ???? Please help it's almost launching time...
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R
R. Palaia
Engine overheating
My first guess is that your raw water intake might be partially clogged. The engine might not be getting the proper amount of cooling water needed at higher rpm's. Roc
My first guess is that your raw water intake might be partially clogged. The engine might not be getting the proper amount of cooling water needed at higher rpm's. Roc
Multiple problems
Clay: I think that you may have multiple problems. 1. Heat exchanger may be plugged. 2. Impeller may need replacing. 3. Check strainer for blockage 4. Check all hoses for kinks or blockage. 5. Mixing elbow may be coked up. ($100 to replace) The Yanmar 2GM/3GM engines should be able to achieve 3600-4000 rpms when the engine is in netrual. The engine is designed to run at 70-80% of max rated RPM's (2500-2900). I was told that you can run this engine upto 3600 for short periods of time 5-10 min. and it should not overheat. The mixing elbow is the most common problem. This would account for you lack of power and your overheating too. If you cannot exhaust you cannot expect the engine to create the optimum horsepower. If you check out this elbow you should have a new gasket before you start. This is not a difficult job but if you have not done it before be aware that it takes 3 hands. I would also purchase the collar that screws into the manifold. If you do not want to replace the elbow, they can be cleaned but you would be better off with a new one. Then you can clean the old one and save it as a spare (probably will never need it again). The first thing to do is to close the thru hull fresh water intake. There are 4 bolts that screw into the engine block. When you remove the exhaust manifold the mixing elbow will come off as one piece. Removing the exhaust hose is also somewhat difficult. This hose can be welded to the elbow. I used a little WD40 and a screw driver to break the seal. The WD also acts as a good lubricant when reinstalling the hose. You should also have some gasket spray/glue to spray on the exhaust gasket when reinstalling. This will keep the gasket in place while you try to get the bolts in place. I assume that the bolts should be torqued to a specific setting but I do not know what the is. If you run you engine at the recommended RPM's when cruising you should not have this problem. Most of the owners think that this range of RPM's is too high, but in fact that is were the engines were designed to run. Good luck
Clay: I think that you may have multiple problems. 1. Heat exchanger may be plugged. 2. Impeller may need replacing. 3. Check strainer for blockage 4. Check all hoses for kinks or blockage. 5. Mixing elbow may be coked up. ($100 to replace) The Yanmar 2GM/3GM engines should be able to achieve 3600-4000 rpms when the engine is in netrual. The engine is designed to run at 70-80% of max rated RPM's (2500-2900). I was told that you can run this engine upto 3600 for short periods of time 5-10 min. and it should not overheat. The mixing elbow is the most common problem. This would account for you lack of power and your overheating too. If you cannot exhaust you cannot expect the engine to create the optimum horsepower. If you check out this elbow you should have a new gasket before you start. This is not a difficult job but if you have not done it before be aware that it takes 3 hands. I would also purchase the collar that screws into the manifold. If you do not want to replace the elbow, they can be cleaned but you would be better off with a new one. Then you can clean the old one and save it as a spare (probably will never need it again). The first thing to do is to close the thru hull fresh water intake. There are 4 bolts that screw into the engine block. When you remove the exhaust manifold the mixing elbow will come off as one piece. Removing the exhaust hose is also somewhat difficult. This hose can be welded to the elbow. I used a little WD40 and a screw driver to break the seal. The WD also acts as a good lubricant when reinstalling the hose. You should also have some gasket spray/glue to spray on the exhaust gasket when reinstalling. This will keep the gasket in place while you try to get the bolts in place. I assume that the bolts should be torqued to a specific setting but I do not know what the is. If you run you engine at the recommended RPM's when cruising you should not have this problem. Most of the owners think that this range of RPM's is too high, but in fact that is were the engines were designed to run. Good luck
C
Carl
3 blade
I just got a 3 blade campbell sailor prop. I should get more power in both forward and reverse with about the same drag. Cost was $440 US. Practical Sailor give them a good rating also.
I just got a 3 blade campbell sailor prop. I should get more power in both forward and reverse with about the same drag. Cost was $440 US. Practical Sailor give them a good rating also.
W
Warren Feldstein
over heating engine
I had a similar problem on a cs36 merlin a couple of years back. The engine could be run fine without overheating except at high rpm. After some investigation, I learned that the impeller as it ages can get soft at higher temperatures. Accordingly, as temperature rises and rpm rises, impeller gets soft and stops pushing water. Try changing impeller and see if this helps.
I had a similar problem on a cs36 merlin a couple of years back. The engine could be run fine without overheating except at high rpm. After some investigation, I learned that the impeller as it ages can get soft at higher temperatures. Accordingly, as temperature rises and rpm rises, impeller gets soft and stops pushing water. Try changing impeller and see if this helps.
S
steven f
heat exchanger
I have to agree with steve D. You seem to have multiple problems, none of which are horrible. Start with the raw water thru hull, is it open and not clogged with marine growth, sea strainer clean, impeller okay? The hose from the impeller to the heat exchanger sometimes gets clogged with sediment and stuff. Than the heat exchanger (the biggie). Is it clear, can you see through the tubes? If so than move on to the elbow and either replace it or clean it. All this is good to check reguardless of anything else, your motor should not be overheating with normal usage and if all these things are clear you'll have a cool (and happy) engine. Now, go on to the prop... Good luck.
I have to agree with steve D. You seem to have multiple problems, none of which are horrible. Start with the raw water thru hull, is it open and not clogged with marine growth, sea strainer clean, impeller okay? The hose from the impeller to the heat exchanger sometimes gets clogged with sediment and stuff. Than the heat exchanger (the biggie). Is it clear, can you see through the tubes? If so than move on to the elbow and either replace it or clean it. All this is good to check reguardless of anything else, your motor should not be overheating with normal usage and if all these things are clear you'll have a cool (and happy) engine. Now, go on to the prop... Good luck.
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