maybe prop question

[captbjack]

allright guys i have 18' pro sport flats boat with 115 johnny with 13 3/8 x 19 pitch prop. my problem is my prop starts to slip when i go around corners and when i try to trim up even just a little. i put a pic on here to see if someone can help. dont mind the cavitation plate, i put in on yesterday before reading the posts here,its coming off did not help.

 

[steelespike]

Re: maybe prop question

I can't tell much by the picture but
Its normal for a prop to be touchy when the setup is on the edge or if prop is nicked up or something disturbs the water around the prop.Turning will raise the prop as the boat responds causing venting.You can lower the engine one hole (verticle height)will probably solve the problem but at the expense of speed and economy.I think a better choice if the prop is aluminum go to a stainless will most likely solve the venting and allow more trim thus speed and economy.You could also add some cup to your present prop just be sure your prop shop knows how much as sometimes this can come out wrong. Stainless is the better choice but is expensive.

 

[captbjack]

Re: maybe prop question

sorry about the pic ,but that is a laser stainless prop and the motor has only 1 hole more i can go down is 1 hole going to make much difference?

 

[Dhadley]

Re: maybe prop question

It's really hard to tell from the pic but it looks like the tip cup is pretty much gone. Try to post a bigger pic or send that one to me at dhadley50@aol.com.

 

[kynolan2183]

Re: maybe prop question

From the pic I see that it looks like your boat is very simular to mine at the stern. My boat has no pad there is a V the hole length of the boat. I had the same problems with venting and finally got it to behave by placing the motor 1/2 of an inch above the bottom of the V. Diffenece in speed was .8 mile an hour on GPS. But it makes it better for Skiing and Tubing.

84 evinrude 70 hp 18 pitch double cupped prop

Kyle

 

[captbjack]

Re: maybe prop question

It's really hard to tell from the pic but it looks like the tip cup is pretty much gone. Try to post a bigger pic or send that one to me at dhadley50@aol.com.

sent you the pic. not real handy with this sort of stuff so let me know if you dont get it. thanks for the help.

 

[Dhadley]

Re: maybe prop question

Got the pic, no problem. That prop looks like the blades of a Ballistic but the hub looks like an OMC. Anyway, with that tip configuration and the lack of cup out there it's no wonder it slips.

We'll assume a couple of things here just to get started. We'll assume it's a 115 crossflow and there is no jackplate. Pro Sports is a pretty decent boat so I'd start with a good 19" prop. If you had a jackplate I'd almost bet you'd end up with a 20 Raker or a 21 SST II or a 21 Stiletto. Maybe a 22 Raker if things went really well.

All that aside I'd not be shocked if that prop slipped.

 

[captbjack]

Re: maybe prop question

Got the pic, no problem. That prop looks like the blades of a Ballistic but the hub looks like an OMC. Anyway, with that tip configuration and the lack of cup out there it's no wonder it slips.

We'll assume a couple of things here just to get started. We'll assume it's a 115 crossflow and there is no jackplate. Pro Sports is a pretty decent boat so I'd start with a good 19" prop. If you had a jackplate I'd almost bet you'd end up with a 20 Raker or a 21 SST II or a 21 Stiletto. Maybe a 22 Raker if things went really well.

All that aside I'd not be shocked if that prop slipped.

awesome job identifing the prop, it is a ballistic i just got back from the river where i changed it to a 17 pitch stainless(doesnt have a name but like a ring around the end of the hub) and it seem to do better but could just be going slower. so could i get a prop shop to cup it again or is it gone?

 

[Dhadley]

Re: maybe prop question

In my opinion - and that's all it is, an opinion - you'd be much better off with something like a Stiletto. Yes, I'd think you'd be slower with a 17. We'll continue to assume it's a crossflow and there is no jackplate. I'd hook up with the prop exchange program here at iboats and try a 19 Stiletto. I think you'll be amazed.

If you hook up with thier exchange program you may find yourself needing a 21. Especially if you get a jackplate.

 

[Dhadley]

Re: maybe prop question

Further thoughts - let's see if we can get Walleyehed's input. I'm sure he must have done some comparison testing. BTW- that looks like an early version of the Ballistic. Or Bullistic.........

 

[captbjack]

Re: maybe prop question

it is a crossflow and i dont have a jack plate. is there any way to tell for sure if i have a height problem?