engine feels and sounds like it is slipping near top end

[jderose840]

i have a late 1980s model 25 hp tiller on a 16 foot aluminum boat used for crapping and fishing. last two trips it feels and sounds like it is slipping at and above 7/8 throttle. only have equipment and two passengers (no different than last 10 trips). i changed impeller and plugs last year. new ball on gas tank and always use some sort of dry gas.

 

[enginepower]

Is prop coming out water that you can see? Not sure why you would take your boat out for crapping...don't have a toilet inside? LOL

 

[jderose840]

yeah my last crabbing trip turned out to be a real crapping trip. 4 hours for 3 crabs and a snapping turtle. not sure why the prop would start coming out of the water on the last two trips. there is a bar that supports the motor when it is up that has about 10 adjustment positions not sure what it is called but it looks like it allows the motor be closer or farther from the boat when under power. which way should i move it. make the motor closer or move it away from boat when under power? it will be a start and hopefully an easy and inexpensive solution

 

[enginepower]

More weight in front or less weight in back will make boat tilt towards motor coming out water. Try moving your adjustment toward the down position to put the prop in water more.

 

[windy5849]

Do you have a spare prop you can try? Sounds like the rubber hub in the prop has broken loose causing the slip under load\speed. Spun prop is a typical term.