markt111

It's that time of year again, in the fall during prop testing I had spun a hub, I am running 23* Mirage plus props on a 30' Scarab Center console
was doing a top speed run at 3/4 trim and the boat almost spun on me, initially thought I smoked a lower but it was the hub, blew out all 3 vent plugs also... has anyone had expierience with this? what would be the cause? could it be the exhaust heat? I am running outboards so no thru hull like most of you!! could it have just been weak? are there issues with the nylon hubs? maybe I was overtrimmed?

BajaRunner

I run the solids. Wont have any problems with those (unless you hit something)

Cord

I ran the nylon hub with 600hp for several years with no problems.

tomas_wallin

I believe the solid hubs are recommended from 400hp and up.

MOP

A lot of guys run solid hubs, it is not a good idea on a clutch dog lower unit. The cushioning the softer hub provides greatly extents the clutch dogs life, I know we are talking out boards but solid hub props should only be used on drives that do not have clutch dog lowers. IE: with a tranny or a cone shift mechanism.

Phil

Darkspoilerzx

Phil hit it right on the head, the only reason the hub is there is so you don't wreck the shift dog in the unit. Not sure on the vent plugs, but is your idle sent correctly that is the biggest thing I have seen with flow torque high idle, or shifting at a rpm way above the recommended level of 800 rpm's. Overheating may have caused it also, do you have your exhaust relieved in any way that it may divert cooling water away from the hub.... other wise it should have plenty and you may have just spun the hub. also make sure you torque the prop nut to the correct spec and have the correct thrust washer in front of it, the new nylon hubs are really crittical to torque on the nut. Sorry for rambling just thinking and typingat the same time. Ed

MOP

The trim angle may have some bearing on the temp but I sort of doubt it, the prop is in a way its own heat sink but its cooling does not transfer much to the hub. Over trimming kills some speed, my thoughts on max trim is to trim until the wheel starts to get a little loose then trim down until the engine sounds solid in the water again. Rooster tails are cool but in many cases SLOW!

Phil