So here is a good one (not a joke)

[Big Cliff]

A friend had an outboard, it would start and run fine until you tried to open it up.

 

So you would get out on the lake and open it up but it just didn't seem to have any power. They tried everything, new fuel filter, spark plugs, carb kit, Seafoam, same thing. Then they changed the prop, problem solved! Seems the prop was slipping on the hub under load.

 

Lower RPMs = not as much load, higher RPMs more load, prop would slip but not enough to let the RPMs go out of wack.

 

Just something to think about if your motor runs fine but can't get you up to speed where you should be!

[mercman]

By HUB, do you mean the rubber insert that is in the center of the prop, or the spline part? My new prop has a 2 pieces plastic torsion hub. are they better than the rubber sleeve type?

[Big Cliff]

By HUB, do you mean the rubber insert that is in the center of the prop, or the spline part? My new prop has a 2 pieces plastic torsion hub. are they better than the rubber sleeve type?

 

The rubber sleave type! I can't comment on the other type as I have no experience with them.

Edited October 1, 2011 by Big Cliff

[Terry]

yup

 

I had the same thing

 

if I got up on plane and and powered up slowly I could get her up to almost full speed but if I punched it at all the hub spun.....

[lew]

Cliff, I've got a rather spendy stainless prop on my motor.

 

Two years ago when I was heading to Lakair, the water was down about 4' and rather than taking a chance on smashing it on a rock, I went to the local marina and bought a regular rather in-expensive prop that was sposed to work on my motor.

 

Same as your friend, as soon as I'd hit around 2500 RPM's the prop would just spin on the hub and the engine would rev high.

 

No other choice but to take it off and put the good one on and just keep my fingers crossed.

[vance]

I know from experience that there are 2 kinds of hubs.One has to be TORQUED on to a certain ftlb to keep from spinning and those that just have to be tight enough to keep from coming off.I always seem to get it backwards :wallbash:

 

vance

[HTHM]

The plastic type hubs are there to fail (break) instead of the MUCH more expensive gears inside of the lower unit. It protects the engine just like a shear pin used to on the lower horsepower engines.

I have one on my Optimax and am very glad of it.

[vinnimon]

I keep a new spare insert in my supply bag, just in case.