I have a 27' Hunter 1982 with a 1GM yanmar. Last season the little engine ran fine.This year I changed the gas filter then bled the injector line. When boat is in gear under way motor loses power.Even with throttle to the max it won't exceed 2000 rpm's. In neutral it's fine. Any suggestions on what the problem may be and how to remedy?
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Bruce
Yanmar Losing Power
Lyn - I had a similar problem - it turned out that when I shifted the boat into forward the engine wasn't actually going all the way into gear. I don't know why but that effected my RPMs. Does your shaft turn normally in forward as well as reverse?
Lyn - I had a similar problem - it turned out that when I shifted the boat into forward the engine wasn't actually going all the way into gear. I don't know why but that effected my RPMs. Does your shaft turn normally in forward as well as reverse?
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Howard
Similar Problem 1978 H-27
I also had a similar problem. It turned out that the engine was fine but the forward clutch plate was worn out and needed to be replaced. How does you engine work in reverse ? If you get full power in reverse the problem may be a work forward clutch plate. I did the repair myself, it wasn't very difficult just a little messy.
I also had a similar problem. It turned out that the engine was fine but the forward clutch plate was worn out and needed to be replaced. How does you engine work in reverse ? If you get full power in reverse the problem may be a work forward clutch plate. I did the repair myself, it wasn't very difficult just a little messy.
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Joe Dickson
Filters?
Did you change both your primary and secondary filters? Is there potentially a lot of sludge in your tank that has plugged up your primary filter a second time? Have you been buying good quality diesel and using a biocide?
Did you change both your primary and secondary filters? Is there potentially a lot of sludge in your tank that has plugged up your primary filter a second time? Have you been buying good quality diesel and using a biocide?
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Tom
Prop
Just a thought, but you might want to check to see that your prop is not fowled with growth or weeds. This will cause a dramatic loss of power. Good Luck.
Just a thought, but you might want to check to see that your prop is not fowled with growth or weeds. This will cause a dramatic loss of power. Good Luck.
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Andy
Lets think about the change
It must be something that you did when you changed the filters. If it ran fine last year, I doubt that its the clutch or the prop (unless your strut bearing froze up during layup). I really think it must be in the fuel system. Did you get the right filter-ya see, the wrong one might restrict the flow under pressure). Could you have crimped a line in the process? Did you change both filters?
It must be something that you did when you changed the filters. If it ran fine last year, I doubt that its the clutch or the prop (unless your strut bearing froze up during layup). I really think it must be in the fuel system. Did you get the right filter-ya see, the wrong one might restrict the flow under pressure). Could you have crimped a line in the process? Did you change both filters?
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Kenny Logsdon
Agree with Andy
I agree with Andy. I have seen this before and given the fact that you were working with the fuel system, my bet is that you have air in the system. Also, there is a chance something didn't get tight and you are sucking air into the fuel system or air is finding it's way back in while the engine is not running. I would check all fittings and then rebleed. Let run at the dock for 15 - 20 minutes at a medium rpm (1800-2200) and see if you can't out work out the rest of the air. Also there should be a small fuel shutoff valve at the tank...make sure it is full open. If this doesn't help, check for water in the fuel. There is a paste stuff (I don't know what it is called) that you put on the end of a stick and drop it to the bottom of the tank. If the paste changes color then there is water present in the bottom of the tank. With the cold Michigan winter, you may have some codensation (always fill the tank for the winter to prevent this). Good luck, Kenny Logsdon, H28.5 "St. Somewhere"
I agree with Andy. I have seen this before and given the fact that you were working with the fuel system, my bet is that you have air in the system. Also, there is a chance something didn't get tight and you are sucking air into the fuel system or air is finding it's way back in while the engine is not running. I would check all fittings and then rebleed. Let run at the dock for 15 - 20 minutes at a medium rpm (1800-2200) and see if you can't out work out the rest of the air. Also there should be a small fuel shutoff valve at the tank...make sure it is full open. If this doesn't help, check for water in the fuel. There is a paste stuff (I don't know what it is called) that you put on the end of a stick and drop it to the bottom of the tank. If the paste changes color then there is water present in the bottom of the tank. With the cold Michigan winter, you may have some codensation (always fill the tank for the winter to prevent this). Good luck, Kenny Logsdon, H28.5 "St. Somewhere"
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Alex
Check Vent
Make sure your tank vent is clear, if that doesn't work change the fuel filter again. Have you checked the air filter? Good Luck.
Make sure your tank vent is clear, if that doesn't work change the fuel filter again. Have you checked the air filter? Good Luck.
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