prop swap.

[bobbyb]

hi all,
finally got new (second hand) motor for my boat so she's ready to go at last.

2007 opti 150 . anyway done all the research on prop and decided on a 4 blade

s/s 17p solas rubex. wrong'*&# only gets to 5000 top end so was wondering

if any you guys are under propped and would like to swap.. must be 4 blade butt.

[Spaniard_King]

what are you looking for Boby??

[bobbyb]

or any suggestion on better suited prop, they say dropping by 1"p will raise revs by 150/200.

i would like to be to wards the top rev rang but cant afford to buy another prop so a swap mite suit some one as well.

cheers...

[bobbyb]

hi spaniard-king,
just want to get my revs up a little. should be between 5000 and 56000. but want 4 blade s/s.

[Gon Fishun]

I would have thought a 150hp would spin the stainless out of that size prop.

[Swanie1975]

What's the engine height like? Did you fit the motor yourself? Any pics?

Cheers Ryan

[bobbyb]

lightning brand, so heavy plate boat. 6 mill hull , 5000rpm at 45 knots.

bit scary looking over the back to see if engine height is right, at least i got that rite.( middle hole.)

I'll do another run yet and play around a bit to make sure trimmed to perfection...

140 ltr fuel, esky, 2 pob so 3 parts loaded.

[Horse]

Why do you think you need a 4 blade prop on that sort of rig. 45 knots is getting up there for top end

[lucee81]

How old is the prop if brand new solas may do a swap, I got my 4 blade from them as they swapped till it was right however I am low looking at going back to a 3 blade prop.

[bobbyb]

thanks guys, 4 blade for for better grip,slower planing, better trim control, ect,ect.

took the gamble on guesstimating prop size and bought for half prise from states. i did toss up buying here for the sake of being able to exchange if not rite. can't win em all.

[Spaniard_King]

something is not right 150 opti gear ratio + 17 pitch + 5000rpm does not = 45 knots

[lucee81]

Slower planing? I get quicker planing on the 4 blade slower speeds and better fuel economy.

[Captain Seaweed]

I think the 4 blade will get you quicker planning, slower speeds and worse fuel economy.

[lucee81]

Better fuel economy I have found. But slower speed less revs and quicker planning.

[Swanie1975]

I run a 4 blade merc prop and can stay on the plane at a lower speed with better holeshot and my top end is 38 knots flat out, slightly faster than when I had a 3 blade prop. Fuel econ is better in the cruising rev ranges with better holeshot.

45 knots out of a heavy boat with 150 hp does sound a tad high - is that a GPS measured speed?

Cheers ryan

[lucee81]

Maybe it's 45km not knotts

[wrxhoon]

something is not right 150 opti gear ratio + 17 pitch + 5000rpm does not = 45 knots

I'm with you Gary, something is wrong there , could be his tacho or speedo ??

5000 rpm on 150 Opti (1.87 gearcase) with a 17" prop works out 38 knts before you allow for slipping at say 10% hat would give him 35kn max.

[Horse]

It could be MPH rather than Knots

[bobbyb]

yep, thanks guys i not 100% sure of the to end speed butt i know 5000rpm is over proped. go for a run sunday and get my facts rite.

thanks........

[bobbyb]

hi all ,
so much for another run over easter, just to much sh*& stuff going on.

i thought it was supposed to get easer. ask mate at work today about our speed the other day and he think about 40 mph?

checked gauger's to find from fisherman's island to nth Morton artificial (round trip) 75.6 miles. fuel used 70.3 Lt's and avg 1.4. so very happy

with fuel consumption. 200 Lt's will take me placers. butt 5000 revs is no good so still looking for prop, is there a 16p 4 blade?

[lucee81]

Mate not sure if the yammie props fit but your more than welcome to test my 4 blade if it does its just sitting in the shed at the moment.

[bobbyb]

lucee81, thanks mate i'll find out and get back to you. i know the merc has 15 tooth spline.. cheers rob........

[lucee81]

I'm away until the 16th so let me know If it will fit and we will work out a time.