Flex Shaft Requirements

[Propjockey]

Just curious. What do you consider the maximum engine size for use with the most common size flex shafts.

.125"

.187"

.250"

 

[John Knight]

I personally use .187 for my 20 and 40. Use .250 for my 60 and 90. All riggers. I know of some that use .187 for 60's but I will not. Besides generally there are more prop options for a 60 with a shaft of .250. Much more torque with a 60 as well.

No real "right" answer but more of preference.

 

[gil sonsino]

I think we have to consider the quality of those flexs too.

I've ran 3/16 on my 67rigger and never had a failure however wouldn't try this diam on my 84 rigger.Also ran 3/16 for years in all my cats even a twin 90 with no problems.All my shafts were hugheys b6666(hardened) and more recently being using CMD ones in all my outriggers.I inspect my flexshafts after every session to check for some failures and in case of doubt change them for a new ones.

Gill

 

[Lay26]

i think it's amatter of prefence, there are some racers i know that run 3/16 on scale boats, but they have square flex hexes and furrels. i like 3/16 on all my 21-45 boats, riggers and sport. it works out great since that's all i run

 

[shoboat]

Fellas,

Generally speaking a 57mm Propeller or bigger should really go 1/4". I know they

work well with 3/16" but they won't last as long as a 1/4".

Good Luck Testing,

Mark Sholund