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ConnManSupraLaunch
08-12-2012, 11:24 AM
Hey gang:

I have 2009 Supra 21v launch. Perfect condition, fluids in check, all is well on the lake but I notice when I am pulling the kids on a tube the boat makes a very unappealing noise when I turn to the right. It's almost like the prop is coming out of the water and is slipping (or the transmission is slipping). Doesn't do it when I turn left. It did this when the back ballasts were both full and empty. It's almost like the boat "shudders" and doesn't sound good.

FYI, I have the rope tied to the top of the tower.

I had noticed it in the past but it seems to have gotten a bit worse as of yesterday. ANY idea what in the world this could be? I saw some other posts regarding slipping tranny's but they were on older model Supra's (1995 and earlier). Help appreciated!

CMSL::confused:

texas_21V
08-12-2012, 08:00 PM
Sounds like prop cavitation to me, especially since it is only doing it when you turn in one direction. I can't see the direction of the turn mattering if it were the transmission slipping. If you are making a lot of sharp turns through choppy water pulling a tube, it is not unusual. Just my 2 cents.

docdrs
08-12-2012, 09:07 PM
I would check your alignment,strut bushings,rudder play and prop to make sure all are within specs. I agree with tex about turning and transmission. How fast are you going when you make the turn, does it matter how gradual or sharp the turn is. There is rudder offset that could possibly be the answer for the noise.

ConnManSupraLaunch
08-13-2012, 09:37 AM
Thanks for the help guys. I have a mechanic who is a Supra Master tech and Im going to have him check it out. I agree with the thinking that when the water is chopped up from pulling a tube it probably disrupts smooth water dispersion through the prop but that doesnt explain why it only does it turning to the right and not left so maybe it is the rudder? BTW - dumb question but what is "prop cavitation?"

Thanks again for the feedback!

C

docdrs
08-13-2012, 12:47 PM
Prop cavitation

http://www.boattest.com/resources/view_news.aspx?newsid=3643

jeffreyk573
08-15-2012, 11:52 PM
I have to say that what you describe is exactly what started happening to us when we started pulling our three person tube with three adults on it. I never tow tubes from the tower, but still have the same vibration/cavitation. It unerved me the first time, but I guess I have a better idea of what it is now.

bmtsupra
08-16-2012, 08:13 AM
Same thing happens when I have my boat loaded down and we're surfing. At first I thought it was the tranny slipping, but it doesn't do it all the time and it doesn't do it at all when we are wakeboarding.

DAFF
08-16-2012, 04:33 PM
What position is the wake plate in ??? Perhaps there is too much downward force in the nose of the boat making a slight air pocket. There seems to be a few people asking the same question, there must be a simple solution or perameter causing the problem.

bmtsupra
08-17-2012, 02:53 PM
What position is the wake plate in ??? Perhaps there is too much downward force in the nose of the boat making a slight air pocket. There seems to be a few people asking the same question, there must be a simple solution or perameter causing the problem.

I run the wake plate in line with the bottom of the boat. I think I need to get more weight. I run 1800lbs when I am surfing and it is all in the back port side. I want to try around 300-400lbs in the bow and on the starboard side next to the motor.