Sooin to be in the 70MPH club

[berg969]

Just got the mod yamaha 50 bigbore prototype finished. had a good run on wed until i saw that the epoxy wont last and i need a welding job. hopefuly i can get it all done tomorow so i can race on sunday in taunton. the motor looks like it should have enough power once everything get set right. the 18 wasnt enough will try the 21 tomorow

[DoktorC]

what props do you use? and what gearing? My brother has a 90 on a 250lb V (a Voodoo) and proping is really holding us back. The only thing we could find that worked is a 24p Yamaha chopper from a V6! It has waay to much diameter but this size engine is very difficult to fit props to.

[berg969]

i usualy use through hub cleavers in the 10.5*18-21 range but have a 12*23 and 14* 25 the gearing is 1.71. i am working on a 15inch 90 yamaha with a 1.71 ratio which should be completed soon