XFS21 Update - Found a prop that works great.

[gpratt]

First off a history on the tuning and setup so far.

The motor is a '06 Tohatsu TLDI 50 hp 2 stroke.

The Original prop that came with the engine is an aluminum 10.5 " x 12" pitch with no cup. That prop was totally useless on this boat. Slippage and cavitation to the max.

Tried a Power Tech 3 blade SS prop 10.75" x 12" pitch with a J cup on the blades. Cavitation/slippage was still a problem but much better than the stock prop.

The last prop is a Power Tech 4 blade SS prop 10.75" x 10" pitch with a J cup. No more cavitation and she will get on plane in a boat length or so. RPMs are right at 5500 rpm at WOT. Right in the middle of the recommended range.

I'll put up some pics of the current setup and some GPS speeds later. I only made a couple of passes out from the ramp just to see how she performed with the 4 blade prop. Next time I'll get a little more detail recorded.

Since the last pics I built a homemade anti-cavitation plate to keep the water hump from the tunnel from being blown apart. The prop shaft housing is right in the middle of the water hump when planing and the anti-cav plate raised to the top of the water hump. I worked out great. I'll try to get some running photos.

[Boo]

Gazooks man we need pic's !!!

Sounds great G !!

[JimW]

Gary,

That sounds right to me. When I went from a aluminum no cup prop to a stainless pro I had to drop from about 20" pitch to 17" to get the RPMs right. But it had a dramatic affect on keeping the prop "hooked up" at extreme trim angles.