High RPMs

[BJ Laster]

I fished a small tourny this evening. When I was running I ran like i do normally except for i hit max rpms at about 3/4 throttle and half trimmed up. Typically I hit max rpms at full throttle and trimming out all the way.. It seemed like i had to keep it at 1/2 to 3/4 throttle and my rpms were above 4500 with it trimmed half out or so.



What happened? When i was launching the lake is down and you pretty much have to beach the boat just to get to the dock. I idle and backed off the trailer in very SHALLOW water. when i went to back off i think the motor dragged a little bit. I didn't hurt the motor did? Could my hub be going out?



Thanks



BJ

 

[BJ Laster]

I checked it at the ramp....it looked ok...



Is there anything else i should check?



Could I have bent a blade or something?

 

[Michael Snow]

This is going to sound stupid but... check the bottom of your hull for some of that fine clay mud we get.



I've had it clump up on the boat, survive the bouncy ride home and fall off days later. You may have gotten some attached to your hull and it's disrupting water flow, causing ventillation.



Otherwise, I'd lean toward a spun hub, but the symptoms don't match. Try pulling the prop off and see if you got some gunk in it/behind it (like weeds).

 

[BJ Laster]

I checked for mud...none.



I have a question tho....i just thought. I know you are not suppoesed to wax the pad..or the hull as some say. A couple of days ago i did wash the hull and the pad with palmolive or some other dish washer soap.....i didn't do the prop but could this be my prob?



There also appears to be a kind of dusty film on the prop. could that be it?

 

[Bryan McDonough]

Probaly from the underwater sand storm created from your prop caused the cloudy look. I'd lean more toward a spun hub. Check for cracks a purchase another hub if you haven't already.

 

[BJ Laster]

well i did go out and try to turn the prop with the engine in drive. It turned with some effort....but hole shot was not effected at all...could it still be the hub?



BJ

 

[David Munaretto]

If i had to guess, I would suggest that laying off of the nitrous oxide may make a difference ;-0



david

 

[Michael Snow]

If the prop can turn without the prop shaft turning, you've got a faulty hub. However, if it's a POWERTECH prop, you can turn it up to about 1/4 inch and it be okay, as they have a funky hubbing that allows this (supposed to be easier on the lower unit when shoving it into gear).



At any rate, what kind of motor and prop? With a Merc, if you're running the Tempest or Trophy, you should have the flo-torq hub which won't slip.. it either breaks or it doesn't.

 

[Travis Smith]

My philosophy BJ,





When in Doubt, wind her out.







Rock on.





T.S.

 

[Dan J.]

If you have a Mercury stock prop that turns while in gear, the hub is spun. Slap a new hub in there and tighten down your prop without over-torquing (I believe @ approx. 40 ft/lbs.) Regrease the shaft with some 2-4-C or equivalent, check/replace thrust washer, remove any mono/debris, etc.... If a blade is bent or more than a 1/4" of any leading edge is gouged, get it resurfaced. It's cheaper than a lower unit. Good luck!

 

[Bruce Freeman]

How was your MPH at max rpm? Down,same,better?

BF

 

[BJ Laster]

I didn't have the GPS with me but by the speedo it was down but just by riding in it...it didn't really seem to change.



BJ