Cavitation/ prop slipping when turning

[Chad36526]

I have a 17' Bullet with a Yamaha 115 turning a 21 pitch prop. Boat comes out the hole fine, runs great as long as you are going strait. When I make any turn while on a plane the motor seems to cavitate or the prop is slipping, it has got worse on the past few trips. I have also noticed a couple of times when running WOT that the prop seemed to have slipped (not enough to change the RPM)but enough to feel it while ridding. Any idea's if this could be a hub going out or something else?

 

[Trent]

Re: Cavitation/ prop slipping when turning

Sounds like the hub is slipping..Mark across the hub with a marker and go try it. If the mark moves you need to carry it to a prop shop and have a new hub installed.

 

[Franki]

Re: Cavitation/ prop slipping when turning

Where is the cav plate in relation to the bottom of the hull??? <br /><br />rgds<br /><br />Frank

 

[Boatist]

Re: Cavitation/ prop slipping when turning

Mark the hub is a good Idea but could also be motor too high in the water. Have you added any weight to the front of boat?? Is motor on a jack plate and has it been moved?? Have you changed to a different prop?? Is the prop dammaged or nicked up on the edge?? Have you added anything new to the transom, Like a Transducer that could be putting air bubbles in front of motor when turning??

 

[Dhadley]

Re: Cavitation/ prop slipping when turning

What brand prop do you have? Ballistic? The technology of the prop determines X dimension (motor height).<br /><br />Good luck!

 

[Chad36526]

Re: Cavitation/ prop slipping when turning

The cavitation plate is level with the hull botom. I do hav3e a jack plate and it is down as far as it can go, It has not been moved since I have owned the boat. The prop brand I do not know, does not look to be a high end prop, but there are a couple of nicks/dings on a couple of the props blades ( 3 blade prop). <br /><br />I can try the hub marking idea this comming weekend, when I am out again.<br /><br />Thanks for all of your help.

 

[chads15]

Re: Cavitation/ prop slipping when turning

Hay Chad.. I was just about to post the same Exact question about my Force 150 doing the same exact thing. so i am going to try what was sudgested and see what happens...

 

[Dhadley]

Re: Cavitation/ prop slipping when turning

What do you mean by a "high end prop"?<br /><br />If your anti ventilation plate is even with the bottom, you most likely could benifit from a better design prop like a stiletto or even a Turbo. You have a jack plate so a 4 blade would easily work. If you are interested, let me know. We'll get you fixed up.<br /><br />Good luck!

 

[Chad36526]

Re: Cavitation/ prop slipping when turning

It has no markings on it other than the size, so I am asumming it is an off brand prop.<br /><br />So a 4 blade high performance prop may help?<br />Contact me at csmith@adam-systems.com<br /><br />Thanks

 

[Chad36526]

Re: Cavitation/ prop slipping when turning

Trent, I marked the hub Sunday,went out, and sure enough the hub is slippling. Time for a prop shop. <br /><br />Chads15, maybe this helps you as well.

 

[Trent]

Re: Cavitation/ prop slipping when turning

Glad you found the problem

 

[FlyBoyMark]

Re: Cavitation/ prop slipping when turning

Check!

 

[chads15]

Re: Cavitation/ prop slipping when turning

I am glad you found your problem!! I too found mine.. it was indeed the transducer from the depth finder. it sits right in the path of the lower unit. so i guess what was happining is it was just blowing bubles right in the path of the prop.. she is performing like i have never seen her perform. thanks alot everyone for the info!!

 

[almost retired again]

Re: Cavitation/ prop slipping when turning

Hi Chad,<br /><br />I don't know , but it sounds like the engine is mounted too high on the transom. It could also be that there is an obstruction creating air bubbles that is getting into the prop stream when turning. I would almost bet that if you lowered the engine one hole that it would stop blowing out on you, but I don't know these are just guesses.<br /><br />Good luck