Prop Spinning In Neutral ?

[mr_grumble2003]

Today was the third time I have taken my new tinnie out. The first and second times I ran the motor on muffs, the prop wasn't spinning at all, today for some reason, it wants to spin, only slow, approx 10 revs a second, enough to be able to stop with your foot, but as soon as you take your foot off it beginns spinning again.

Any ideas anybody ?

[Coast_Bloke]

Sometimes if the water is exhausted thru the prop it may move a little. And some drives just spin a little bit.

Also take the cover off, and run the motor in neutral. If the actual drive cog spins, then your motor may have an issue. If not, switch the motor off, and spin the prop by hand (MAKE SURE MOTOR IS OFF, AND IGNITION IS OFF) if cogs turn, then drive is stuck in gear, if not then its prob just the exhaust turning it or something like that, no probs.

Edited April 26, 2006 by Coast_Bloke

[The Iceman]

Nothing to worry about The water pressure is spinning the water pump impellor which will slowly turn the prop The impellor was probably a little tight in the housing being a new motor so a little bit of use has freed it up

[Grantm]

I would say there is no probs at all. Dont think the wpump has anything to do with it though. The impeller is keyed directly to the drive shaft which is spinning as fast as the motor. From there the shaft enteres the gear box where the it is connected to the drive pinion.

The drive pinion sits between the drive gears ( forward and reverse ) and drives them at engine speed which free spin on the prop shaft from memory which is blury at best, they are always connected but the drive gears are not splined to the prop shaft. When gear is selected the dog clutch basically engages the prop shaft to the selected drive gear.

Now what you will find is that the drive gears ( which are connected to the engine drive shaft )but free spin on the prop shaft are actually indirectly spinning the prop shaft slowly from fluid drive. Like a torque convertor.Gear box oil which is in between the drive gear and the prop shaft is indirectly making the conection. This explains why it is easy to stop.

Very confusing and if you followed that your doing well.

Another way to explain it perhaps is imagine you had two pieces of pipe one which slips loosly over the other. Fill the gap between the two pipes and spin the outer one at 700 rpm. Naturaly the inner pipe will turn from the indirect fluid connection between the pipes.

Thats how i remember it anyway but like i said its a bit blury.

[Sammy0884]

I would say there is no probs at all. Dont think the wpump has anything to do with it though. The impeller is keyed directly to the drive shaft which is spinning as fast as the motor. From there the shaft enteres the gear box where the it is connected to the drive pinion.

The drive pinion sits between the drive gears ( forward and reverse ) and drives them at engine speed which free spin on the prop shaft from memory which is blury at best, they are always connected but the drive gears are not splined to the prop shaft. When gear is selected the dog clutch basically engages the prop shaft to the selected drive gear.

Now what you will find is that the drive gears ( which are connected to the engine drive shaft )but free spin on the prop shaft are actually indirectly spinning the prop shaft slowly from fluid drive. Like a torque convertor.Gear box oil which is in between the drive gear and the prop shaft is indirectly making the conection. This explains why it is easy to stop.

Very confusing and if you followed that your doing well.

Another way to explain it perhaps is imagine you had two pieces of pipe one which slips loosly over the other. Fill the gap between the two pipes and spin the outer one at 700 rpm. Naturaly the inner pipe will turn from the indirect fluid connection between the pipes.

Thats how i remember it anyway but like i said its a bit blury.

spot on grant!