Prop Advice

**fishin2day** · 07-27-2009, 10:03 AM

Hi everyone new airboat owner here. Just looking for a little advice. I was recently given a 16 foot-wide beam airboat from some friends. It had been sitting in a barn for years, and after a engine overhaul and a little paint, wood, carpet etc... I got her looking and running good. It has a Rotax 503 motor with a gear reduction drive of 2.58. I bought a used 2 blade wood prop from an ultralight field nearby (stamped for a Rotax 447) and after running it a few times it just seems like there is alot of drag with the 16 foot boat, and seems like I should get more speed out of her. I was hoping you guys could help me out on a prop recommendation. The cage has room for a 60" blade.

Any advice would be appreciated.
Thanks, Jason

**buster** · 07-27-2009, 03:19 PM

Hi, and welcome to the forum,

I am sure other members with a lot more experience on airboats than me will soon chime in. It seems to me you have an awful large, and probably heavy hull to expect much performance from with that engine.

Papee has what he refers to as "The Tank" and it sounds about the same as yours. He pushes it with an 084 engine. I am quite sure you will get a chance to compare notes with him shortly.

Where abouts do you hail from?

Dave

**fishin2day** · 07-27-2009, 05:08 PM

I live in Illinois southwest of Chicago.
The boat was originally built by Panther Boats in Florida. Had their stickers all over it. So it must have run
good at some point. When I got it there was no prop, so I do not know what came with the boat.
The way the motor and fan assembly is put together, I think I could retrofit the assembly pretty easy onto a smaller jonboat if there is no hope for "Tank 2"
Like I said any help would be appreciated.

Jason

**Papee** · 07-27-2009, 05:41 PM

Spyda ryder is the resident guru on the rotax motors. You may want to PM him. If he has notifications on he will see it.
Here's a link to his profile if you want to PM him.
memberlist.php?mode=viewprofile&u=101

**Duane Scarborough** · 07-27-2009, 07:27 PM

fishin2day,

My "guess" is that you just don't have the right prop. A Rotax 503 is good for about 50 HP. With the right prop, you should be good to go. I don't imagine it'd be race boat material, but should be a good ride boat.

I suggest that you give Panther a call. Find out what prop it originally had.

Duane

BTW, welcome to the forum....

**Duane Scarborough** · 07-27-2009, 08:14 PM

fishin2day,

Since you've got a Rotax, you might want to check this site out:

http://www.ultralightprops.com

They build fixed and adjustable pitch wooden props for Rotax applications.

Direct contact information:

Rick Peter
GSC Systems [2004] Ltd.
#8 - 2440B - 14th Avenue,
Vernon, BC, V1T 8C1
250-549-3772

Duane

**chuckitt** · 07-27-2009, 08:54 PM

Hey fishin2day, Thanks for posting on the mini forum.
A 60 inch 3 blade Warp Drive with the Rotax bolt pattern will work good. It is adjustable to get the engine to the right RPM. It sells for $ 1135.00
A 60 inch 3 blade IVO will also work good and comes in the Rotax bolt pattern. With it you must have about 4.5 inches clearance in front and back of the tip of the blades. It sells for $ 600.00 plus shipping. The IVO is also adjustable.
Thanks, Chuck

**fishin2day** · 07-28-2009, 07:57 AM

Thanks everyone, the advice is appreciated.

**Wildfowl** · 07-28-2009, 08:49 AM

Originally Posted by Duane Scarborough

I suggest that you give Panther a call. Find out what prop it originally had.

In all fairness that would be "assuming" that Panther had anything to do with the motor currently mounted on the boat. There are a lot of hulls for sale out there and even more examples of multiple engine switches.

For what that's worth anyway.