v-drive vibration

[Jmac572]

Just looking to see if anyone has any quick advice for this... I get a vibration on my 390 Sundancer between about 2800-3300 RPM that smooths out after that and cruises beautifully. Bottom is clean. First V-drive boat, any help to leads to get this figured out is much appreciated. I would think if it was a drive-shaft or prop issue it would only get worse with higher RPMs.

 

[Jus Cruisin]

Check motor mounts.

 

[Jmac572]

Check motor mounts.

Ty, the engine and v-drive mounts are secure and torqued to spec

 

[techmitch]

If you are absolutely sure you don't have anything fouling your props or shafts, check the cutlass bearings and shaft alignment.

 

[Jmac572]

If you are absolutely sure you don't have anything fouling your props or shafts, check the cutlass bearings and shaft alignment.

Thank you, yea we just launched for the season in early June and the problem occurred right away same day. The cutlass bearings were solid and props/shafts clean. I'll have the marina check the alignment, ty.

 

[The Bill Collector]

When I did my cutlass bearings 2 years ago I sent the couplers, shafts & props in for a tune-up. The props were true, but the shafts & couplers were a little out of spec and adjusted appropriately.

 

[Jmac572]

When I did my cutlass bearings 2 years ago I sent the couplers, shafts & props in for a tune-up. The props were true, but the shafts & couplers were a little out of spec and adjusted appropriately.

What did they get you for that job $$$?

It's strange to me because the vibration smooths out on plane, seems like if the props/shafts were out of balance or alignment the vibration would get worse, not smooth out.

 

[The Bill Collector]

What did they get you for that job $$$?

2 Cutless $256, 2 props $200, 2 couplers & shafts $600, labor $1000 + yard time $1000

 

[capecodcruiser]

What did they get you for that job $$$?

It's strange to me because the vibration smooths out on plane, seems like if the props/shafts were out of balance or alignment the vibration would get worse, not smooth out.

Think of it this way if shaft or props are out of balance. With a car that has a tire of out balance, they usually show up at a certain speed, than goes away above or below that speed. Similar situation. Our season is so short, try to live with it till the fall and diagnose when out for season.