planing issue

[haywire]

does not have any speed we have a small 17' maycraft 800 lbs.with 3 persons weighing 665lbs,i would add about 300lbs for gear, we are gps's at 8 knots max out rpm, we dont have tach so no rpms- would guess to max out about 4200r's,prop on it is a 10 1/2 x 14, 35 hp johnson 2000, my idea is to cut the prop down to 9" with the pitch 14
would doing this have an effect to increase rpms closer to the recommended range of 5200- 5800, or is this a waste of time ,i dont have alot of money to spend on it right now but i need to do something to keep it from lugging the engine
any thoughts deeply appreciated
i am trying to get wiring diagram for the tack wire colors to hook up

 

[steelespike]

Re: planing issue

Its a real crap shoot to change props without a tach and speed.
Both from a performance standpoint and the health of your motor.Speed alone really means nothing.All that said a 14 is too much prop.
Don't cut down the prop.If you do it yourself you'll be unbalanced and I don't think a prop shop will do it.Running unbalanced could cause premature beraring and seal failure in the gearcase.You may be able to work a swap on craigs list or a prop shop might take the 14 in trade toward a prop they have, possibly used.Cherck out flea markets,garage sales marinas,back yard outboard mechanics..Marina might do a partiasl trade toward a used prop.

 

[hwsiii]

Re: planing issue

Haywire, I agree with Steele don't cut the prop down. My program shows you should be running a 12" pitch prop, but it sounds like something is wrong if you can't get on plane with just 2 people and no gear. Try just two people and tell us can you get on plane and how fast you are going, then we can help more.

H

 

[haywire]

Re: planing issue

thank you guys I kinda thought that cutting it down would be a waste of time so , I found a prop calculator and said I needed a 10 1/2 x 11, they will also exchange it if it still is not right so I am going to purchase a new one, still working on a wiring dia. so i can hook up tach
we are on plane but only 8 knots gps 3 people

 

[Dhadley]

Re: planing issue

"i am trying to get wiring diagram for the tack wire colors to hook up"

Grey wire is the sender wire from the motor.
Black is ground.
Purple is battery + (key "on" power).
If it has a wire for the light it should be blue.

 

[haywire]

Re: planing issue

Thank you Dhadley