John B

Team Yahoo, 36 Skater, 500 EFI's, props shaft 2" above the bottom before and after. Tested with 3 sets of props and lost 3- 5 mph and 200-400 rpm. Skegs were cut down 2". Reason for change: cracked 4 lowers just above the carrier! Has anyone had or heard of these results and has anyone found any solutions? This is like loosing 60-80 HP. This is very depressing. Thanks for any replies. John B

Goodfella

Sounds like the boat needs to go back to THE LAKE and get dialed in again. Whenever you make a drastic change like that your going to expect some changes positive and negative. You just have to work through them.

Good Luck

Mbam

What ratio?

mr_velocity

that boat had #6s on it, did you make the change or did you get the boat that way. It was the fastest 500hp 36 with #6s I've seen. Those boys from TX had it dialed in.

Mbam

Also, sounds like the drives are too low based on the larger props and built-in set back of the drives if mounted at the same propshaft c/l as the Bravo's..

John B

See below

John B

Guys, Light it was running 113, now it runs 109 light. The drives (shaft height is the same as before + 2" from bottom), and props are the same. These skegs are much thicker (may be 3/8's") and longer front to back than the B1's. The water pickups are smeared all over the lower nose cones and the case is a little bigger diameter. The water coming off the bottom only hits the carrier case on the bottom below the shaft centerline, hence the water pressure runs between 8 and 13 lbs.

Velocity, This is the original Yahoo 1 which set the APBA Kilo record in 1999 at 112.864. I bought it from Curtis when he was buying a Supercat. He was accustomed to winning and wasn't so he bought another 36 Skater to run in F3 and called it Yahoo Too. That one had 6 drives. Yahoo 1 was tested in Powerboat Feb 2000.

Marc, 1.36

Anybody else?




Go back to the previous page.

Mbam

I am stupid! I should read more carefully, I assumed you meant you went to speedmasters, you mean you went to sportmasters!

What pitch props? Any chance you can raise the drives? What was the ratio before change?

Sydwayz

iTrader: (1)

It sounds like you just have too much more drag. Bigger cases and thicker skegs will do that. Maybe shave the skegs down to razor sharp leading edges and see if you can a get a tad bit more.

Also, aren't the gears cut differently (more square) in the Sportmasters? If so, you are losing a few more ponies in the drive itself; especially since it is spinning thicker (read heavier) shafts, right?

Sounds like a walk around the dry pits before a race and taking a few notes and pictures would help. You know those guys make them as fast as they can.

rpm

If you went from Bravo's to #6's at the same x dimension, you need to raise the x dimension. #6's are designed to run higher.