Propeller for a 2 cycle 40 hp

[Jacob McCandles]

My current propeller on my 04 Yamaha is a 10 5/8 x 12-G I am considering going to a 11 x 15. Would going to a prop this size put too much load on the engine. The boat is a Lowe 170 SE. What affects on the performance should I expect.
I am considering the Solas make the Amita 3 AL 3311-110-15 for price reasons but the site has a Yamaha prop the same size for more money. Is there a quality difference between the two.

[bajakeith]

props

why do find a lot boats over propped and almost never under propped ???.. to answer your question sir..you must use a tach to measure your WOT rpms with a normal load..and IMO is one of the most must have gauges on a boat !! there are some after market hr/tach unint that gets a wire wrapped around a spark plug wire and that would take two people..and I don't know how accurate that would be..myself have A 'FLUKE" and a CDI 2 stroke noise filter

[99yam40]

17 foot boat with a 40 is going to be under powered and tough on the motor unless you stay with a small prop. how does it run with the prop you have on it?

What is a CDI 2 stroke filter?
I have not heard of this before

[bajakeith]

99yam40

LOL..do you remember agent 99 ? LOL..check out CDI ELECTRONICS..a American co that does outboard with great products..cant be beat for the good stuff IMO... under tools your find all kind of outboard testing goodies..A real tech's candy box...PS Woo Roo,,, I let the cat out of the box !!! LOL

[99yam40]

yep I do.
But 86 would not have matched my 1999 C40

I will have a look

[99yam40]

I looked and did not see a CDI 2 stroke filter

[bajakeith]

s o b

I looked and did not see a CDI 2 stroke filter

your Right !! I could not find on there website catalog ????? I have the paper catalog (thank god) and I bought it many years ago..I have a lot of their tools as you can figure as to why..good tech stuff and better than OEM parts IMO..I have tech support in my cell and will call um Monday..its a basic two banna style plug unit about a inch long and filters stray RFI that older two stroke ignitions are famous for and makes the fluke rpm inductance pick up work like it should.. a most accurate tach that I can take boat on a run or in the shop and get a true RPM reading..capt K