pitch got me buggered??

[blu]

I have never understood pitch.. my boat 4.8 osprey (alloy) the prop on the boat says 10x10
the spare is 10 3/8 x 12 1/2
witch of these would be beter on fuel???
the donk is 50hp

[Crooked]

Blu,
That's a really good question......and I have no idea of how to unravel those numbers either!!!!

But I thought I;d reply anyway and hopefully someone is more cluely than the both of us!

cheers

[blu]

thanks Crooked glad i'm not the only one

[trilogy]

Blu
Propeller pitch was once explaned to me as ,If you get a big block of butter and twist the prop in one complete revolution and then measure the distance the prop travelled this would be the prop pitch.If the prop travelled 10 inches in one revolution the pitch is 10, If it travelled 12 1/2 inches the pitch is 12 1/2. The first number is the prop diameter in inches.
Depending on boat loads the best way is to test both props in the same conditions with the same load and see which is best.
Hope this helps.

[krazyfisher]

10 x 10 =10 inch dia and 10inch pitch that is if you were to but it in a solid and make 1 turn it would move forward 10inches. like a cork screw.

the prop that suits your motor the best will be the best on fuel. try each prop and which ever puts the revs in the higher end of the rev range will be the best.
too big of a prop you will not get the revs and the motor will labour and use more fuel. too small and no speed.

does this make sence?

[blu]

thanks trilogy makes sence

[blu]

thanks krazyfisher but i dont have tako unless somone can tell me how to hook up a OMC tako to a Merc motor or swap my OMC 4 a Merc thay don't need??

[tigermullet]

That first prop is way too low in diameter and pitch for that size of alloy boat and 50hp motor unless carrying an enormous load. Do you have a rev counter? At a rough guess, if you generally carry only one other person and an average amount of gear it should go better with a larger diameter and a pitch above 17. That's just a very rough estimate but the situation needs looking at for the sake of the motor.

[blu]

thanks tigermullet thats a huge help

[rayken1938]

Give the guys at solas propellers at the sunshine coast a ring. 1800333342. no hard sell and free advice. I have found them excellent and spot on with their advice. If you decide to buy a prop off them they offer a try it and buy it service and if its not right they will exchange. Their prices are way below genuine prices also. Have a look at their website. They are also at most boat shows.
Ray

[tigermullet]

Sorry Blue - There was typo in my previous post. Meant to say above 13 inch pitch but agree with Rayken to get the experts involved. Solas should be able to sort out the problem very quickly.

[blu]

thanks I will ring them on monday and have a look @ the web site agen thanks 2 u both and all concerned 4 help;D