We also have a vibration starting at about 1800 rpms. New cutlas bearing, alignment good, prop recently redone. Any ideas? No smoke at higher rpms either.
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B
Bill O'Donovan
Who knows
Sounds like you're in shipshape condition. Sometimes engines rattle at funny RPMs. The main question is whether the shimmies go away at the proper RPMs of 2800 or 3000 depending on your horsepower.
Sounds like you're in shipshape condition. Sometimes engines rattle at funny RPMs. The main question is whether the shimmies go away at the proper RPMs of 2800 or 3000 depending on your horsepower.
G
Guest
that's another problem
can't get up that high on rpms. We think the prop is the wrong size, though we do know it's balanced. was once a repo boat, also maybe in charter.
can't get up that high on rpms. We think the prop is the wrong size, though we do know it's balanced. was once a repo boat, also maybe in charter.
What boat and engine are we dealing with?
Molly: Fill is in on you boat, year, model, engine, prop etc. A vibration at different RPM ranges are not uncommon in most diesel engines. If you have a Yanmar, you should be able to rev to 3400-3800 in neutral (the govenor is suppose to prevent higher RPMS). If you have a two bladed prop, you will tend to have more vibration than with a three. If you engine will not rev to these higher RPMs in neutral then you need to start doing some research in the area of the engine. The mixing elbow is a good place to start. The elbow gets plugged up with carbon and restricts the flow of air and water. This can sometimes cause overheating too. Give us some more info and let us see if we can help.
Molly: Fill is in on you boat, year, model, engine, prop etc. A vibration at different RPM ranges are not uncommon in most diesel engines. If you have a Yanmar, you should be able to rev to 3400-3800 in neutral (the govenor is suppose to prevent higher RPMS). If you have a two bladed prop, you will tend to have more vibration than with a three. If you engine will not rev to these higher RPMs in neutral then you need to start doing some research in the area of the engine. The mixing elbow is a good place to start. The elbow gets plugged up with carbon and restricts the flow of air and water. This can sometimes cause overheating too. Give us some more info and let us see if we can help.
G
Guest
info on boat
1986 Morgan 41 Classic, 44 hp Yanmar 4JHE boat does not get up to max rpms, only about 2600. vibration starts at 1800. New cutlass bearing, alignment good, new PYI coupler/shaft saver, motor mounts okay. Engine does not vibrate, overheat, or smoke. Prop is 3 blade, 17 - just redone, but may be wrong size. Boat weighs 23,000. Thanks
1986 Morgan 41 Classic, 44 hp Yanmar 4JHE boat does not get up to max rpms, only about 2600. vibration starts at 1800. New cutlass bearing, alignment good, new PYI coupler/shaft saver, motor mounts okay. Engine does not vibrate, overheat, or smoke. Prop is 3 blade, 17 - just redone, but may be wrong size. Boat weighs 23,000. Thanks
K
Kevin
Where to start.
In my opinion vibration is BY FAR the most difficult item to track down in any running gear. As I always suggest to my customers, start at the engine and begin to move aft. I believe that the propeller is, in most cases, the speaker that informs you that something is going on. We have pinned down noise to the fact that the fuel was dirty. Couplings out of round, couplings used multiple times before replacement the list goes on and on. If you zap to me a note of the kind of noise you are experiencing I would be happy to help try to shed some light. Kevin
In my opinion vibration is BY FAR the most difficult item to track down in any running gear. As I always suggest to my customers, start at the engine and begin to move aft. I believe that the propeller is, in most cases, the speaker that informs you that something is going on. We have pinned down noise to the fact that the fuel was dirty. Couplings out of round, couplings used multiple times before replacement the list goes on and on. If you zap to me a note of the kind of noise you are experiencing I would be happy to help try to shed some light. Kevin
M
Molly
noise
It's a loud rumbling noise at about 1800 rpms. loudest in the back of the boat. We did figure out the rpm problem. Nut that adjusts throttle was way in and against a bar. Rpms are good now, will test it out Thursday.
It's a loud rumbling noise at about 1800 rpms. loudest in the back of the boat. We did figure out the rpm problem. Nut that adjusts throttle was way in and against a bar. Rpms are good now, will test it out Thursday.
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