Need suggestions for new prop

[nova_gts]

I have a Avon 10' RIB with a yamaha 15hp 2 stroke on the back.

I am not positive but I think stock pitch is 10.5, I was wondering what I should use as a replacement, here is just what I was looking at.

Quick silver Alumnium 10.5"pitch - 120$
Solas saturn 11" Stainless steel 11"pitch - 112$
solas amita 11" Alumnium 11"pitch - 50$
Piranha - 150$ (not sure they are any good)

Any advise would be appricated

 

[nova_gts]

Re: Need suggestions for new prop

I did verify that the stock is 10.5, the only prop they make with that same pitch is the quick silver which is a lot more than the solas, how do the 2 brands compare?

 

[nova_gts]

Re: Need suggestions for new prop

Also does anyone have an suggestions for a dolphin for ease in planning? I really didnt want one that required drilling holes.

 

[steelespike]

Re: Need suggestions for new prop

For the health of your motor and for best performance we need your actual prop size and present max rpm and speed.Before trying a foil you might try raising the motor on the transom,perhaps a tiller extension so you can sit in the middle seat.A tinytach is easy to install and works on any similar motor without regard to stator poles.

 

[alamosaddles]

Re: Need suggestions for new prop

Also does anyone have an suggestions for a dolphin for ease in planning? I really didnt want one that required drilling holes.

I saw in either the West Marine catalog. or the Boaters World catalog, a new hydrofoil wing adaptor that allows you to install the wing WITHOUT drilling anything into your cav plate.

 

[nova_gts]

Re: Need suggestions for new prop

I have played with the tilt and having people move forward, both helped, espically with the passanger moved forward. I was just thinking a wing may help more esp in rougher waters.

oem prop size is 9 1/4 x 10.5p, as for the rpm's I have a pretty good ear for that sort of thing i can hear when I get on plane it is WOT and slowly catches up. Between what looks like 5000k rpms and WOT the speed of the boat does not change much, but the engine does sound like it is spinning faster. I believe the reason it does not speed up is because of the poor condition of the prop on it currently. I would be willing to hook up a tach but I do not have one.

Is the way it basically works, if it will go WOT to the maximum rated RPM's then you can upsacle the pitch, and if it will not hit the max rated RPM's then you need to drop one size down?

Thanks for the help.

 

[steelespike]

Re: Need suggestions for new prop

Yes your on the right track downsize for more rpm etc.
A tinytach is about $40 and will fit any 2 cyl 2 stroke motor.
Do you know that your prop is indeed the oem 10.5?If it happens to have a 9" and you go to a 9 you have wasted your time and money.if it is a bigger pitch you may gain too much rpm.
If your propping by sound (if your good)you could be 200 to 300 rpm off and not know it.
You could be sacrificing performance, mileage and motor health.
If you miss on the size it wouldn't take long at over $4 a gallon to waste the cost of a Tinytach not to mention engine repair/maintenance
The size and shape of your boat makes it difficult to plane especially with any load.A foil should help you plane and stay on plane but it may actually reduce your top speed and waste fuel.I'd rather spend the money on a tach
and optimize the setup.

 

[nova_gts]

Re: Need suggestions for new prop

Yea, I did pull the size off the back of the prop, so that I am sure of. Do you know if I can get a tiny tach at walmart? I just didnt want to order it and have to wait for one more week till I could find out the results due to shipping time.

Do you have any suggestions in regards to stainless vs alumnium and solas vs quicksilver?

Thanks for the help

 

[nova_gts]

Re: Need suggestions for new prop

http://www.tinytach.com/tinytach/gasoline.php
TT226NR-1C

--- Can you please verify that is the correct tach? and if you know of anywhere I can buy one as apposed to order, it would be appricated.

 

[nova_gts]

Re: Need suggestions for new prop

Ok, so I just went ahead and bought the tiny tach, unreliable site said ships between 3-10 days. Blah, I did no want to wait that long, So I was also looking at the hydrofoil,
that bracket(which I assume you were refering to, looks like it would cause a lot of drag, any one have it before? it also doesnt seem like they make them for small engines... I assume that this is what you are talking about

http://www.westmarine.com/webapp/wc...L=true&storeNum=6&subdeptNum=240&classNum=384

 

[GiMLit]

Re: Need suggestions for new prop

My recommendation
You can't buy something you need locally or don't want too look around for it.
Use the best site around for online orders.
iboats!!!!!!!!!!!!!!!!!!!

 

[nova_gts]

Re: Need suggestions for new prop

Yeah, Well I am going to get a prop from here, I wish there was somewhere you could just go and try out props to see what works best oh well **** happens... I got the tack from tinytach, they suck, I want it asap so I can get fitted with the new prop!!!

 

[nova_gts]

Re: Need suggestions for new prop

Tiny Tach read with only myself onboard 5770 RPMs WOT. I will test out to see how it is with several passangers later on this evening.

 

[nova_gts]

Re: Need suggestions for new prop

With 2 smaller people (130lbs) and 1 bigger (200lbs) + cooler and gas - tachout WOT was 5200-5300 took about 15 sec to get on plane shifting weight forward.
3 small people + gear = 5450 WOT (8 sec to get on plane with shifting weight forward)
2 small people + gear = 5500 WOT (5 sec to get on plane with shifting forward)
These were all semi rough conditions.

 

[nova_gts]

Re: Need suggestions for new prop

Also not sure if it makes a difference or not, but my prop is in horrible condition... it looks like a dog chewed on it.

 

[steelespike]

Re: Need suggestions for new prop

I don't have specific info on years but the 15 developes its power at 5,500 rpm. Only guessing but I would think 57 or 5800 would be within max numbers you may want to check your manual or with a dealer.Your ratty prop may throw the numbers off I would get the prop repaired it seems to be a good match and it may get closer to 5,500 with you alone and may help hole shot as well.Would be interesting to see mph by gps.
560 lbs of people plus cooler and motor must be close to capacity
that performance sounds pretty good to me.

 

[nova_gts]

Re: Need suggestions for new prop

I'm not gonna repair, Not worth it. I wanted to go either 1/2 up or 1/2 down to an 11 or 10 pitch. I usually like to roll with 3 people smaller (including myself).
I was just hoping you'd advise if the alu solas was a good prop, and if so I guess i'd go for that.

 

[steelespike]

Re: Need suggestions for new prop

Found your old note.If your stuck and have to go up or down a half I would go down a 1/2.I feel its better to be slightly under propped because you can allways throttle down a little when alone and still have plenty of push when loaded.Can't help on the Solas except don't recall any Solas trouble posts.

 

[nova_gts]

Re: Need suggestions for new prop

Results:
10"P - 2 people max RPM WOT - 6000
1 person - 6150

Prop looked very nice, blades were a bit wider so it weighted a little bit more, but other than that, thickness was the same.. over all it looked like a very good quality prop.

I'm just wondering if with RPM's so high will it damage the engine, and should I have gotten something bigger?

 

[steelespike]

Re: Need suggestions for new prop

I think when running alone I would stay under 6,000.I think it developes its power at 5,500 and usually "they"run motors up to about 500 over that.
But We don't know if yours can be run up to 6,000.It does appear your 10.5
was darn close to what you need.By the way the Evinrude 15 developes its power at 5,500 and can be run to 7,000.Just to give you an idea of what your might be able to do.The dealer may have some max figures and perhaps the 5,500 is considered the top.