Prop problem?

[Coyote6943]

Manufacturer:Johnson VRO<br />Year:1985<br />Model:J50TLCO<br />Power Tilt and trim<br /><br />I have been having problems with my motor. It is on a 17' Fisher Aluminum flat bottom bass boat. The engine itself runs great, at low speed everything seems to be fine, when I try to accelerate something seems to slip the motor will rev high like there is no more resistance from the prop/water. It does not happen all the time, one day I will take it out and it is fine the next it starts "slipping" and doesn't stop. I have checked the oil in the lower unit which was fine, I have a second prop that I put on, ran great for weeks then started to slip again. I was thinking that it may be the prop, it is a through exhaust with the rubber bushing, I thought maybe the bushing was worn and needed to be replaced. In case you don't know already I am kind of a newbie to outboards and boats in general. Any assistance you can give me would be appreciated.<br />

 

[Bob_VT]

Re: Prop problem?

A few things to check. You might have two bad props (unlikely that two are bad but....) Mark the prop with a laundry marker with a line drawn from the nut to the ouside of the prop. After the slipping check your marks, if they do not line up it is time for a new hub in the prop.<br /><br />Your motor may be too high and you are getting cavatation. Try tilting the motor down a notch not trimming so high.<br /><br />The prop ventilation plate may be mounted too high in relation to the hull. Look at the engine mounting bolts and see if you can lower the motor one notch on the transom.<br /><br />Is this a new boat to you? Make sure you have a 20" motor on a 20" transom and not a 20" motor on a 25" transom.<br /><br />Bob