Polycraft 455CC Prop sizes

[cheno]

Hi Guys,

I just picked up my new 60 yammie 4st for the new poly centre console.

These motors come with a 13 inch pitch prop which is a big fan for a small boat like the poly so I'm swapping it for an 11".

I'm keen to hear what prop sizes other poly owners are running with the yammy/merc/mariner 60 4-stroke.

Cheers

[piscator]

Its all about RPM and pitch Cheno. The lower the pitch the quicker you get out of the hole and slower you go at WOT.

I run a 12" on a 40HP Honda on a CC as well and I can get very close but never over 50KPH on the GPS, the good thing is that this setup doesnt take that loong to get there!.

Have a muck about with the myriad of prop calculators on the net, supply realistic variables, and you'll probably find that your setup may get you a touch over the "magic" 50KPH for a 455 in ideal conditions.

Best advice is, talk to Steve Evans at Solas props and see what advice he has to offer on the matter. He's always been helpful to me and will bend over backwards to please.

Goodluck with the poly mate, they are tops!. I'm still yet to see one on Sydney Harbour. ???

Brett

[bay_firey]

I reaaly don't think you will have much trouble getting over the "magic" 50kph with a 60 on a c/c.
Flat chat wot I can get 52 kph with my 50, 2 adults (1 is a big lad) and 1 child, full tank and a days gear.

I think, so don't quote me, I will check latter, that I am running a 13" pitch on my Suzy 50

[cheno]

I agree, the boat that I went for a run in was a cc with a 60 merc 4st and did 38mph (almost 61kmh). Can't remember the prop size though.

My thoughts on the smaller pitch were to do maximising acceleration and being able to hold a decent speed into a head sea all possibly at the cost of a loss in top speed.

I talked to a guy at solas today who said that they now manufacture an ally prop that is designed specifcally for this motor and has a slightly larger blade area than the yammy factory props. I might try one out if I'm not satisfied with the performance of the factory prop.

[Cloud_9]

generaly the factory prop is pretty close. but you will find that they are a prop that will suite a glass boat or a heavy boat because they have to allow that the average 4.55 hull weighs so much and the outboard has to perform.
if you go smaller than what is needed you will us tooo much fuel & rev the tits off the motor.
find out that revs that the motor sould be doing at wot load your boat with the normal crap that you will carry and with add of a borrowed tacho you need to be in the rev range that manufacturers recomend.
mate has 60 4s merc on 4.8m glass think he has 13p
if boat is lite go bigger on the prop.
with my boat its lite for size and i had to go up 2 prop sizes which is unherd of and took same cashing down.
but the end result is good boat speed and maximum fuel economy.

Cheers Cloud 9

[Big_Kev]

I run the factory prop on my 4.75 alloy c/c 60 Yammie 4 and I am in no rush to change it.
I get 49kph/5600rpm going by the gps and I am happy with that.
Trolls at low speeds if I want, gets out of the hole good with weight and the bit I like best is the fill up with the economy.

[Big_L]

I'm running a 12 pitch on 35hp 3cyl Johno on a 4.55 poly, a bit slow out of the hole, top speed on GPS 38.9K @5200, I think I need to go to a 11p to get 5500rpm and might be a bit quicker out of the hole ???

[phewy]

hey Big_L, I woulnt worry about speeds or "hole shots".??? Aint we just going fishing after all? Who cares if you get to the spot 5-10 secs later than someone who spends up to $1K on their special alloy or SS props with their special computer designed pitch or dia sizes. If we had ski boats then sure. Anyway, whats the big deal about getting out of holeshots?. Save your money and just enjoy getting out there! [smiley=2thumbsup.gif]

[Big_L]

Hey Phewy it's not about getting there quick,it's about running your motor efficiently and not making it labor. [smiley=thumbsup.gif]

[GBC]

Anyway, whats the big deal about getting out of holeshots?.

Phewey,
The ability to slide of the back of a wave and then nail the boat to drive away from the angry great green thing trying mount the rear of your boat, easily and without snapping the throttle controls of the motor trying to get more out of it, is called holeshot. A geat thing to have and take for granted, and something you'd sell your soul for when the green monstor is steadily gaining.....

[phewy]

Dont know bout that big-L, banging your throttle down to get a good hole shot doesnt sound like running your motor "efficiently" to me and so doesnt wanting to make your motor rev out higher ???. I'll just continue to take it quitely and easy, not out to impress anyone. And with sensible and careful boating skills should never come accross a big green monster coming from behind me. And if one does by circumstances I know my fact motor and prop will do the job. Just my opinion anyway.

[Big_L]

Each to their own Phewy

[phewy]

Good fishin to ya Big_L [smiley=laola.gif]

[cheno]

Tried the first prop an 11" pitch Yamaha with two up plus esky, saw 6200 on the tacho at WOT. Speed only in the low 50s but the holeshot was pretty savage. Have now grabbed a 12" pitch and will try that soon.

Has anyone tried Solas' wide blade area alloy props that they market for the 50 and 60hp 4 strokes?

[piscator]

Cheno

See my earlier post. The prop I run is one of the "wide blade area" solas aluminuim jobs - bought because I wanted a bit better acceleration.

Its 11.6 " diameter and pitched at 12". Matched to a 40HP Honda I can almost get 50km, two up, full tank and gear etc, in good to average water.

I took off the stainless Vengeance that came with the rig, it wound out to about 5850 and I hit 53 kms in the same water. That prop is a 13" pitch.

Cheers
Brett