PDA

View Full Version : Turning a prop by hand



wolfstone
09-16-2010, 09:08 AM
On my Moomba V 2000, i can rotate the prop by hand but its like turning over an engine, feels like there is resistance.....easy in some places, worse in others.(almost like fighting compression)

I can rotate it about 60 degrees with all my strength of both hands applied.

Is this normal?

Or should the rotation be easy to complete with one hand say?

Maybe this signifies a bent prop shaft?

It has been this way for 3 years now, with no effect on the running.

Can anyone turn their prop easily by hand?

MartinCaron
09-16-2010, 10:09 AM
My 03 lsv act exactly as you describe

zegm
09-16-2010, 02:00 PM
On my Moomba V 2000, i can rotate the prop by hand but its like turning over an engine, feels like there is resistance.....easy in some places, worse in others.(almost like fighting compression)

I can rotate it about 60 degrees with all my strength of both hands applied.

Is this normal?

Or should the rotation be easy to complete with one hand say?

Maybe this signifies a bent prop shaft?

It has been this way for 3 years now, with no effect on the running.

Can anyone turn their prop easily by hand?

You should be able to easily turn it by hand.
As someone who has had a bent shaft that eventually failed (and left us in the middle of the lake at sundown) you should get this checked out. Yes a powerful V-8 will turn it no problem (a slightly bent shaft) but eventually like any metals you are bending it back and forth and one day the shaft will snap in half. Also keep in mind there are bushings in the strut and they may need to be replaced also as the bent shaft is working against them wearing them out also (another NOT easy job to do). If you wish to do this yourself you must be able to remove the engine side flange off the shaft, sometimes it will come off easily, other times you will need a puller or press. If you need these tools to take the flange off then you must pull the motor out of the boat to get the shaft out of the hull as the flange will not pass through the hull and there is no room for the puller. Maybe on a v-drive there might be other options but I am sure it won't be easy. Once you have the shaft off you need a good flat surface to roll it on. You will then see if it is bent.
PS Once the shaft did break the shaft and prop slid back into the rudder, so I had to have the prop repaired also. That was a fun summer!

viking
09-16-2010, 02:30 PM
mine turns easily with one hand!

Bent shaft - MAYBE - Could also be a sign of being out of alignment??

DOCDRS
09-16-2010, 05:14 PM
there is a very easy way to get the coupler off the shaft , you do not need a puller :)

zegm
09-17-2010, 12:13 AM
there is a very easy way to get the coupler off the shaft , you do not need a puller :)

Well you say that but you didn't say how. I have seen some just come off in my hands and some I had to put in a press. Depends on how well it is seated on the taper.

If the motor is out of alignment then usually it is hard to turn all the time. My LS came with its second motor way out of alignment.
When the shaft is bent/bowed it will be easy then hard.

In 20+ years of owning a MC Stars and Stripes I only ever had one prop, sure it was in the shop (Marine Wheels of Panama City) a few times, but I had no less than 3 drive shafts with the same boat!
The last shaft was custom made since I could not get a factory part anymore but that was relatively easy here in this Port/Town. The problem I had was the shaft came with the flange on it and there was nothing short of a large press that would get that flange off. I was not about to pull the motor to install it.

DOCDRS
09-17-2010, 01:28 AM
loosen the nylock nut off the coupler, but not all the way off the the prop shaft threads, then insert a smaller nut or socket inside the nylock against the end of the propshaft so that it is protruding past the nylock and the coupler, then pull back against the drive shaft coupler and using 2 bolts tighten until propshaft coupler breaks free. (if driveshaft coupler has center opening you will need flat stock or lay another wrench across opening and use longer bolts to pull the 2 couplers together) tighten each nut about 1/8 of a turn at a time......this will act as a press to free the shaft coupler

zegm
09-17-2010, 01:50 PM
loosen the nylock nut off the coupler, but not all the way off the the prop shaft threads, then insert a smaller nut or socket inside the nylock against the end of the propshaft so that it is protruding past the nylock and the coupler, then pull back against the drive shaft coupler and using 2 bolts tighten until propshaft coupler breaks free. (if driveshaft coupler has center opening you will need flat stock or lay another wrench across opening and use longer bolts to pull the 2 couplers together) tighten each nut about 1/8 of a turn at a time......this will act as a press to free the shaft coupler

Great idea!!!
My problem was when I ordered the new driveshaft I sent them my flange to the machine shop turning my new shaft to make sure they turned the right taper on it. Well I couldn't then get the driveshaft into the boat as I could NOT get that flange back off. I had to take it to work and put it in a press to remove it (BANG!). It was either that or lift the engine up and out of the way and that is another story in itself as I have pulled a motor from a boat once to rebuild it.
Again Great tip!!!!

deafgoose
09-17-2010, 09:39 PM
I got my goggles on today, got under the boat and was able to turn my prop with two hands. It had the same resistance all 360 degrees so I am confident my prop shaft is aligned. Woot!

DOCDRS
09-18-2010, 12:54 AM
i can turn my propshaft at the coupler in the boat with one hand when it is not aligned......don't kid yourself, the only way to know if its aligned is to check it with a feeler gauge at the coupler.....it only takes 20 mins and you don't have to get wet !!!!!! there is no laser or computer alignment..it is all done by hand.....do it yourself or take it to a shop and have them check it

thesack
09-20-2010, 02:46 PM
Remember that your strut bearing is water lubricated. So if you are attempting to turn your prop after being out of the water for a while, you will most likely have resistance.

Typically a bent shaft or mis-alignment will cause a vibration while the shaft is turning. This vibration will also increase as the mph/rpm increase.

zegm
09-30-2010, 03:41 PM
Remember that your strut bearing is water lubricated. So if you are attempting to turn your prop after being out of the water for a while, you will most likely have resistance.

Typically a bent shaft or mis-alignment will cause a vibration while the shaft is turning. This vibration will also increase as the mph/rpm increase.

I had a slightly bent saft for years and she was a smooth as could be! Well Ok the engine was sitting on an old rotten wooden stringer so it probably dampened the vibrations a good bit. Never mind!