Have a 2GM20 with stock 2 blade prop (2001 h290 puchsd in 2002). Been living with this issue for as long as I've had the boat, but not sure if its 'normal'. Only happens if I throttle down quickly from either F to N, or R to N. The whole drive drive train vibrates nastily for about 1 second, shaking the boat a bit. I know it can't be healthy, so I've been trying to minimize the occurance by always throttling down very gradually, but this is not always unavoidable, esp around the docks and anchoring. Anyone else have this phenomenom? live with it? fixable? I'm thinking this has to do with the transmission/prop not being able to react to change as quickly as the engine, and so they contend with each other until things equalize Don't really have any other real complaints about either the engine or transmission. no real bad points of vibration at certain RPMs. very smooth otherwise While here, for those that have this boat/engine/prop, what are you getting for max RPM and top speed at max ? This boat seems to be a real 'dog' on aux. Just glad to be using where there are no big current or waves Thanks, Brian
Drive train "shudder" on throttle down
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Drive Train
Had the same problem with my 2001 H340 which has a 3gm30f Yanmar. I increased the idle speed rpms and that seemed to fix the problem.
Had the same problem with my 2001 H340 which has a 3gm30f Yanmar. I increased the idle speed rpms and that seemed to fix the problem.
Vibration
You also might check for loose motor mounts and shaft/flange alignment. I bought new 1995 29.5 with the 2gm20f engine and had similiar probs that were caused by loose motor mounts that were never tighten at the plant. Your symptoms are not normal and should be investigated by your Hunter dealer.
You also might check for loose motor mounts and shaft/flange alignment. I bought new 1995 29.5 with the 2gm20f engine and had similiar probs that were caused by loose motor mounts that were never tighten at the plant. Your symptoms are not normal and should be investigated by your Hunter dealer.
No Dog
I can go 6.5 knots with no problem at 3100 rpm's on my 2001 290. I did have to clean out the mixing elbo this spring and a clean prop will also give you better performance,I have never had a problem with the boat being under powered it motors very well for me at all times. nick
I can go 6.5 knots with no problem at 3100 rpm's on my 2001 290. I did have to clean out the mixing elbo this spring and a clean prop will also give you better performance,I have never had a problem with the boat being under powered it motors very well for me at all times. nick
Same here
Brian, you're not alone; Fred's boat is one hull ahead of mine, so I've paid attention to his comments, but I have the same symptoms; at times, it's pretty scary how much shaking the engine can do. Sure, raising the idle did help, but the engine, particularly if just warming up, can produce a death rattle. Its done this from day one, so I've accepted that the Yanmar just hates a certain, low RPM when warming up. Once up and running, not a problem. Curious if others have this, even if they've upped their idle to get the engine out of this range. (just to know if misery loves company). Its not loose motor mounts nor shaft alignment, no prop (does it in neutral). Max speed 6.4knots; max RPM 3200-3300 no load; never run it above 2800. She moves along quite nicely when happy.
Brian, you're not alone; Fred's boat is one hull ahead of mine, so I've paid attention to his comments, but I have the same symptoms; at times, it's pretty scary how much shaking the engine can do. Sure, raising the idle did help, but the engine, particularly if just warming up, can produce a death rattle. Its done this from day one, so I've accepted that the Yanmar just hates a certain, low RPM when warming up. Once up and running, not a problem. Curious if others have this, even if they've upped their idle to get the engine out of this range. (just to know if misery loves company). Its not loose motor mounts nor shaft alignment, no prop (does it in neutral). Max speed 6.4knots; max RPM 3200-3300 no load; never run it above 2800. She moves along quite nicely when happy.
Long Shot
It may be a long shot, but my boat was vibrating while in gear. It turns out that my strut bearing was worn out, which wore out the strut, which wore a spot on my shaft. to check this while the boat is in the water, dive under the boat, grab the shaft and shake the crap out of it. If it moves at all you need to replace the bearing. This was causing vibrations on my 30. again it's a long shot. good luck on solving your problem.
It may be a long shot, but my boat was vibrating while in gear. It turns out that my strut bearing was worn out, which wore out the strut, which wore a spot on my shaft. to check this while the boat is in the water, dive under the boat, grab the shaft and shake the crap out of it. If it moves at all you need to replace the bearing. This was causing vibrations on my 30. again it's a long shot. good luck on solving your problem.
worn cutless-not a long shot!
don't write this off as a long shot! we had a severe vibration at higher rpms that turned out to be a worn cutless-after only about 60 hours from delivery, probably because the drivetrain wasn't properly aligned by the dealer! my marina installed a new cutless and aligned everything, no more vibration.
don't write this off as a long shot! we had a severe vibration at higher rpms that turned out to be a worn cutless-after only about 60 hours from delivery, probably because the drivetrain wasn't properly aligned by the dealer! my marina installed a new cutless and aligned everything, no more vibration.
Maximum RPM for 2GM20
We purchased a H280 this past March. The owners manuel does not say anything about was is the Max. RPM. It runs around 6 knots at 4K but that may be too much. Is there any benefit of going to a three blad prop. Currenly have a 2 blad folding prop.
We purchased a H280 this past March. The owners manuel does not say anything about was is the Max. RPM. It runs around 6 knots at 4K but that may be too much. Is there any benefit of going to a three blad prop. Currenly have a 2 blad folding prop.
Max RPM on 2GM is 3600
Eric: The max rated RPM is 3600, one hour at 3400 and cruising should be 70-80% of max (2500-3000). You just need to be sure that the prop matches your boat/trans/engine combo. It sounds like you are under propped! Do you know what prop you have on the boat. The normal for this engine is somewhere around 15x9 - 15x12
Eric: The max rated RPM is 3600, one hour at 3400 and cruising should be 70-80% of max (2500-3000). You just need to be sure that the prop matches your boat/trans/engine combo. It sounds like you are under propped! Do you know what prop you have on the boat. The normal for this engine is somewhere around 15x9 - 15x12
Upping RPM fixed it
Thanks for all the advice. I checked the idle speed and it was slightly low, so upped it to about 900 and now the shudder at throttle down is completely gone. I'll be pulling the boat this winter, so will check prop and shaft closely as well.
Thanks for all the advice. I checked the idle speed and it was slightly low, so upped it to about 900 and now the shudder at throttle down is completely gone. I'll be pulling the boat this winter, so will check prop and shaft closely as well.
Check other stuff
Glad to see you found the problem,when you take the boat out and put it on the hard,its a good time to check the raw water pump inpeller,and the mixing elbo also. I just cleaned the mixing elbo this spring and changed the raw water pump inpeller,very easy job to do. This sping when the hull was clean and prop was clean and cleaned out elbo my 2001 290 rpm's were 3400 and the boat felt like better than new ,she would would reach 6.5 very fast in all condition's,I was amazed at how well it performed under power,some times when I would throtle down all the way black smoke would come out the exhaust but it does not do that any more and the engine always sounds so good. I have a manual for the yanmar engine's and it has helped to do some of the maintance. nick
Glad to see you found the problem,when you take the boat out and put it on the hard,its a good time to check the raw water pump inpeller,and the mixing elbo also. I just cleaned the mixing elbo this spring and changed the raw water pump inpeller,very easy job to do. This sping when the hull was clean and prop was clean and cleaned out elbo my 2001 290 rpm's were 3400 and the boat felt like better than new ,she would would reach 6.5 very fast in all condition's,I was amazed at how well it performed under power,some times when I would throtle down all the way black smoke would come out the exhaust but it does not do that any more and the engine always sounds so good. I have a manual for the yanmar engine's and it has helped to do some of the maintance. nick
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