boat over revving please help!!!!

[cmoore43]

Ok i just bought an very well keep 1991 nitro. it has a johnson 115 on it. (no clue the year)my question is when ever i try to "put the hammer down" and the boat starts to plane out, it sounds like the boat is over revving. it runs fine going slow or at a moderate speed but after that nothing happens just over revvs.

Can anyone explain????? please

 

[fishrdan]

Re: boat over revving please help!!!!

Spun prop hub?

 

[tpenfield]

Re: boat over revving please help!!!!

Well, you would want to have a tachometer to know for sure what RPM you are achieving. Also a GPS of some sort to see if you are getting RPM increases and little speed increase.

If the RPM's are too high, then a new prop of higher pitch. The RPM's vs. speed will give an indication of what you need, if anything.

 

[steelespike]

Re: boat over revving please help!!!!

Things to check.
Take the prop off and put a water proof line across the hub,do a test run and check the line it will be broken
if the hub slips.
is the prop in good condition?
The antivent plate(just above the prop) should be about even with the bottom of the transom.Pictures would help tell.
Have you tried different trim settings. Is there anything on the bottom or transom that might disturb the water ahead of the prop?