why is my motor "slipping"

raptorschild · 05-18-2008, 09:30 PM

When I attack the throddle too fast my motor "slips", and the RPM's go though the roof with no acceleration. Basically my engine tries to red-line, but it feels like my prop doesnt exist.

I drove though a bunch of debris on the Powder river this weekend, and my motor started doing it when I even slightly tried to accelerate!!!! was kind scary....thought I really messed something up. I checked the prop for debris by lifting the motor, and it seemed to fix itself.

Interesting.

Its a 25 hp merc pushing a 16 ft smokercraft (sylvan) aluminum boat if anyone is wondering.

Herring Impaired · 05-18-2008, 10:20 PM

Do you have a slip hub on the prop? May have "Spun" it.... Or perhaps a "Shear Pin"?

HntnFsh · 05-19-2008, 02:13 AM

I thinl Herring impaired is right.Sounds like you spun a hub on your prop.They can be fixed

fishkisser · 05-19-2008, 06:03 AM

sounds like a spun hub to Me too ...

retaliate · 05-19-2008, 07:04 AM

Yep! spun Hub is likely, I spun a hub once, hitting something in Coos Bay, I was able to get a few mph, but any more throttle would rev the motor to dangerous levels, most modern props have a inner hub, that can be replaced without buying the whole prop.

Chrome Bumper · 05-19-2008, 08:16 AM

spun hub or ventilating prop. Try your spare prop.

raptorschild · 05-20-2008, 11:02 AM

Wow, thanks for the reponses. This site is great for the non-mechanical types like me!

thanks a lot guys!

Hunt'nFish · 05-20-2008, 01:56 PM

What motor & prop is it?
I agree about the spun hub...but some have to be repaired and some you just re-tighten the nut and all is good.
They are designed to spin on the hub if you hit something rather than bend the shaft.
I had one spin on my old Merc and I just tightened it and it never did it again.oat
Figured since I carry a spare prop, I could just swap if it continued.
Hunt'nFish

raptorschild · 05-21-2008, 07:33 AM

Quote:

Originally Posted by Hunt'nFish

What motor & prop is it?
I agree about the spun hub...but some have to be repaired and some you just re-tighten the nut and all is good.
They are designed to spin on the hub if you hit something rather than bend the shaft.
I had one spin on my old Merc and I just tightened it and it never did it again.oat
Figured since I carry a spare prop, I could just swap if it continued.
Hunt'nFish

The debris at Powder river was bad and I was flying throug it all weekend, so I'm sure thats what happened.

The motor is a 25hp 1996 merc. I'll give the nut a squeeze, and see if she like it!