Prop spin while towing

B

Bill K

New member
I am coming from inboards to an outboard so don't know the answer and a search didn't reveal an answer.

Does the prop spin while driving down the road and if so does it hurt the shaft seals ?

Thanks

Bill Kelleher
 
There is some back and forth in various boating forums as to whether the motor should be in neutral or in gear when trailering.

There is also some difference of opinion by the engine manufacturers. The manual for the Mercury outboard I used to have did say to have the motor in gear when trailering. The manual for a Yamaha motor I have does not say anything about this. The manual for the BF90D on my C-dory also does not say anything about this.

With the Yamaha I put it in gear when trailering. Since it was an open boat it was easy to see if the selector was in gear or not. With the C-Dory I have intended to leave it in gear, but because the selector is inside the cabin and not visible I usually forget to do it.
 
Thousands of mile of trailering, usually with the motor in neutral and not motor problems. I suspect the best thing to do is to put it into gear, but I almost never do. My motors are usually tilted, and I've had "following" vehicles with friends in them who tell me that the props move very very slowly.

Bottom line is that if I think about it before closing up the cabin, I put both motors in gear. If I didn't think of it, I lose absolutely no sleep over it.

I would think that with true inboards that the shaft bearings and logs are often intended to be wet and a turning shaft out of the water might be a problem for that design.
 
Agree, that with the motor tilted up, there is little issue. The speed of turning is very slow. There is lube in the gear case--and wear on the seals is minimal. no cooling necessary.

As for inboards--pretty hard to get them to spin in the wind! Even under sail, they props turn slowly at 5 knots. I usually locked them because of vibration and noise, but not because of wear.
 
I had a kicker motor that destroyed its propshaft seal by spinning in the wind while trailering.

The propshaft has two seals back to back. The outer seal (behind the prop) is lubed by the water when running. The inner seal is lubed by gear oil.

I learned to 'put the kicker in gear' when trailering. That lesson cost about $300 to rebuild the gearcase. The outer seal was destroyed by the 'dry' spinning, allowing water to be sucked into the gearcase later, when operating in the water.
 
After reading this I'm thinking that there may be an upside to trailering with the engine(s) in gear, and there is probably no downside? (Except for having to remember.) Would that be fair to say?
 
Couple of questions, first, Larry what kind of kicker and about how long did it take to ruin the seals. I have a Yamaha that I have been towing in the down postion and in neutral for years with no problems. Second Jim, why reverse as opposed to forward. I understand the idea of not having the prop turn in the airsteam but did they say why reverse? Thanks
 
Spike":vhsltr8l said:
Couple of questions, first, Larry what kind of kicker and about how long did it take to ruin the seals. I have a Yamaha that I have been towing in the down postion and in neutral for years with no problems. Second Jim, why reverse as opposed to forward. I understand the idea of not having the prop turn in the airsteam but did they say why reverse? Thanks
Click to expand...

My question, too!

About the only reason I can think of is that in reverse the throttle body butterfly valve(s) will only be partially open, whereas in forward it could be up to 100%, letting bigger bugs and other critters into the fuel and air intake system and beyond. :smileo

Joe. :teeth :thup
 
I take a somewhat easier approach - I fix a bungie around one blade (which locks it in position) and clip the hook(s) to the forward edge of the lower unit.

Best,
Casey&Mary
 
Casey":u81fb4pg said:
I take a somewhat easier approach - I fix a bungie around one blade (which locks it in position) and clip the hook(s) to the forward edge of the lower unit.

Best,
Casey&Mary
Click to expand...

I would be sure that there was very little tension on the prop blade; those bearings are only designed for an axial load.

Cheers!

John
 
The kicker was an 8hp Johnson 2-stroke. The spinning was probably going on for over a year when trailering.

To stop the prop spinning, just put in into either gear. There is no need to open the throttle.
 
I just made a note to myself to put mine in gear.

My kicker is a 8 hp Johnson !

Bill Kelleher


Larry H":21h8lhk9 said:
The kicker was an 8hp Johnson 2-stroke. The spinning was probably going on for over a year when trailering.

To stop the prop spinning, just put in into either gear. There is no need to open the throttle.
Click to expand...
 
Interesting point. On my 3 mile tow to John Wayne I doubt it will make much difference at 35mph. However, I will put a note in the boat to put them in gear for the long rides.

Harvey
SleepyC:moon
 
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