View Full Version : Outboard motor question

10-12-2005, 07:08 PM
When I push down the throttle on my outboard fast as if I was trying to pull up a water skier it slips out of gear. It's almost like when your cluth is going out in your car and you push the peddle to the floor it slips up to 4000 rpm. If I slowly give it throttle until I'm up to 3900 rpm it will hold but above 3900 rpm it will rev up the motor and it will stop the rotation on the propeller ???

Vance Staplin
10-12-2005, 08:01 PM
Is your motor actually kicking out of gear? It sounds like your prop hub is slipping.


10-12-2005, 09:10 PM
No it's not kicking out of gear it just revs the enging and it stops giving forward motion like I said almost like a clutch on a car when it's slipping

10-12-2005, 09:14 PM
It does sound like the propeller hub rather than a lower unit problem. When the lower unit slips, it jumps in and out of gear with an audible "clack".

10-13-2005, 05:50 AM
Sierra-Hillbilly only fish and your prop will not slip in the hub. ;D ;D ;D

Vance Staplin
10-13-2005, 11:56 AM
Hi S_H,

My guess is you have a unit older than 1995 that has a pressed hub in the prop. If so it is best that you take your prop to a prop shop and have them rework the hub.

That should solve your problem and it is way less $$ than a lower unit problem.

You can send it to Phil's props in Redding via ups. They do awesome work and are very reasonable. Their phone number is (800) 462-3917.

Hope this helps


10-13-2005, 05:54 PM
S H. What motor do you have and what is the prop size?

10-14-2005, 05:43 PM
I have a 70HP Chysler. I'm not sure of the prop size. To be honest with you I'm really dumb when it comes to boat motor work. I can work on cars but boats are a diffrent story. Where is the prop hub and how do I get to it? I've taken older 8hp two stroke apart but I have no Idea where the prop hub is? Please help

10-14-2005, 05:51 PM
Sierra Hillbilly,

The hub is the center part of the hub. On some props its made out of a rubber composite like material. This protects the lower unit from shock if the prop hits something.

Here's some info I just found doing a search on Google.

Q. What is the purpose of the rubber cushion hub in an outboard prop?

A. It is not intended to prevent blade damage as is sometimes assumed. This device protects lower unit parts by cushioning the shock of propeller impact. Its prime purpose, however, is to prevent excessive breakage of shear or drive pins that otherwise should occur due to the jolt or shock that is experienced in the process of shifting gears.

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Q. The rubber hub in my propeller seems to be slipping. Is this possible?

A. It is a definite possibility, but it does not occur too frequently. Take a look at the propeller. If the blades are visibly bent or distorted, you very likely are experiencing cavitation__ and cavitation is often mistaken for a slipping bushing. Have it checked by the prop manufacturer or a reliable prop service station. The bushing can be replaced if it needs it or the blades can be restored to proper accuracy to eliminate the cavitation.

10-15-2005, 07:06 AM
Thanks Dennis that makes alot of sense now. Basically it's the center portion of the actual prop. So all I would have to do is remove the prop. I don't have to remove anything else. Maybe I can just buy a new prop all together. It does have some bent portions on one of the blades. Maybe it could be both the prop and the hub.

10-15-2005, 12:06 PM
after you get thhe prop off look very carefully where the alum meets the center section. if you can see any marks it has been slipping. i think its 40-50 bucks to have a new hub put in at a prop shop and while its there they can straighten and or weld what is needed for more money

10-16-2005, 09:24 AM
If you decide to buy a new prop, you can tell them you typically fish at higher elevations. They'll recommend a prop that will preform better and get you on plane faster. The drawback is a lower top end speed.
If you want you can talk to Mickey, I think he went down one to two sizes. Can't remember if it was pitch and diameter or just pitch.

10-16-2005, 12:24 PM
SH, Don't know where your located but if your not to far from Lodi there's Delta Propeller @ 110 Commerce St, Phone 209 366 1555. I had the prop off of my 15HP Honda rehubed there last spring. the price was reasonable [around $35] and had it back in a couple of days. Good service and nice people. ---fish hawk

10-16-2005, 12:46 PM
Thanks Fish Hawk. I'm in Placerville so if someone knows a place in Sacramento it would probably be better.