A lurch a surge or a slip -- please tell me what it is......

[jwhposon]

I have a SAN 210 2004. I sometimes experience a free spin of the prop (maybe) or the transmission or V-drive. I have not been able to determine where it comes from. It happens only in a turn - generally when I am pulling a tube while ocilating the throttle. I will get this deep lurge or surge - almost sounds like the prop hit wood or something, but no damage there. Everytime it does happen it is only seconds and then it goes back to normal. Is there any way I can test this?


I do have a leak in my V-drive - maybe.

I had to change my fluids - tranny and v-drive a awhile back and i was thinking it had something to do with my fluids.

Anybody help?

Jason

[surroundsound64]

RE: A lurch a surge or a slip -- please tell me what it is..

Do you have the factory prop on it? I don't know much about this... but at a certain RPM (depending on the pitch) I think the prop will develop a pocket of air... or something other than water around it, and the prop will just spin.

[Mikeski]

RE: A lurch a surge or a slip -- please tell me what it is..

Gasp... tubing behind a 210, should be illegal.

It is probably cavitation, check if you are have pits on the backside of the prop blades. If the tranny fluid is low it can slip in the turns, the oil in the V-drive is just for lubrication, it won't slip but it will burn up.

[Onthewater]

RE: A lurch a surge or a slip -- please tell me what it is..

If you aren't turning hard it probably isn't breaking loose, is this a straight line in decent water slip or in heavy chop?

[Hollywood]

Re: A lurch a surge or a slip -- please tell me what it is..

It happens only in a turn - generally when I am pulling a tube while ocilating the throttle.

[ag4ever]

RE: Re: A lurch a surge or a slip -- please tell me what it

Cavitation. Happens to me when pulling tubes behing my SANTE.

BTW, my wife was pulling me and a bud on a 2 man tube. She was actually able to launch the boat out of the water. All we saw before being thrown was the entire hull out of the water with the prop spinning.

[surroundsound64]

RE: Re: A lurch a surge or a slip -- please tell me what it

Wait.. so someone explain what cavitation is exactly... Pitting in the back side of the prop? How does that cause slipping?

This is interesting.

[jthooker]

Boaters often use the word “cavitation” to describe what is actually “ventilation”, which sounds like what Jason is experiencing. When a power boat abruptly looses forward thrust in a turn and the engine revs up it is almost always ventilation. This occurs when air is channeled under the hull to the prop or the prop rises too close to the surface of the water. A good example of this is when we do a power turn in a ski boat, the prop grabs air (ventilates), looses its thrust, and the boat immediately heels down in the water. Ventilation can also occur during less severe turns depending on factors such as total load, load placement, point of tow rope attachment, and direction of turn versus direction of prop rotation. If you Google “prop cavitation” you will find a number of articles and technical discussions about the subject.

[surroundsound64]

Ah.... Maybe that's what I remember hearing about.