What prop to get?

[Brad Y]

Currently the prop on my 50hp merc blows out on high speed turns and im looking at a new prop to stop this happening as often and as easy. A few exra mph would be great as well.

Heres some info i have found and have to work with.

Currently acheiving

35mph
5300-5400 rpm

Using a 14" pitch aluminium 3 blade prop.

I have tested a 4 blade stainless prop a size smaller in pitch and it got the engine revving to 5650rpm whcih is over the recommended range, but i got an extra two mph out of it and the handling was magic. I could actually trim it a long way out and it still held.

But for the price, i dont think i could justify the 750 dollars.

So what options are avialable? Are there aluminium 4 blade props with the same cup and rake characteristics?

Im also going to check out the new hustler props from BLA, though the sizes are one size lower and one higher than my current one only.

I also have the capacity to lift the outobard two holes. I did this with the current prop and i spent last weekend having a terrible time with the motor trimmed way too far in for comfort, but it was necessary to stop ventilaton. SO one hole is looking a more resonable option if i get a higher cupped prop to hang on more.

I have been told to keep the revs up and the smaller props will do this, but im thinking more and more that a raides motor will allow a hundred or two rpm to be achieved, maybe allowing the larger pitch to be used.

Anyone know if there is a place in perth that allows a try before you buy? Dont laugh as there is at least one place in the SOUTH WEST that does it so surely perth dealers will.

Cheers for any input

[Bear]

Yatesey, have a chat to Mullet. You know how fussy he is and after a lot of testing he actually tried something a little different.

HTH.

[Brad Y]

One step ahead mate, i spoke to him on the phone the other week. He has one of the hustlers, great sounding prop for the price and exactly what im looking for. Just doesnt come in the size i am looking for. I will check with BLA when i come up tomorrow.

[Stu_000]

Ring Mick at Just Propellors in Osborne Park

He will have some answers for you no doubt

[Rossco32]

Just Propellors In Osborne Park.

I'm running an alloy Solas 4 blader.

I used to get 35 mph @ 5600 rpm using a 13 1/4 x 19" pitch 3 blade alloy.

I'm now running a 4 bladed 14" x 19" Solas Amita, that combined with a 3" engine lift has netted me a 14 mph increase in top speed (unladen) and rpms top out at 5400 (100 under rated max). The boat handling is an absolute joy! All torque loading through the helm is now gone and the hole shot is still pretty sweet.

Now I can actually utilise the trim without the prop blowing out and I have a nice little rooster when running flatout and trimmed for max (gps) speed.

There is better bow lift and she planes @ 2300 rpm.

I'm only running an early 90's Yammie 2 stroke on an older glass "bass' hull..... nothing too flash.

If I remember rightly I paid $375 for that prop.

HTH.

Rossco

[Brad Y]

Cheers guys

I have had some contact with mick and we bith agreed on a few things, like stainless probly isnt worth it for that size motor.

Ross, I saw you last sunday on the water i think- i was in the blue bass boat. Your beast looked sweet as when you gave it some juice.

Not really wanting to spend a heap on it thats all, i have the ability to raise it but its actually already pretty high- last weekend i had the cav plate over an inch out of the water and it hated it. Its lowered back now and with a new prop i will slowly raise it for best effect.

[Rossco32]

I thought it was you but didn't want to make a dick of myself if it wasn't

3 blades can never be run really high at low rpms (my motor has a 2:1 gear reduction so @ 5400 rpm the prop is only turning @ 2700), where as the cupped 4 bladers love it.

My cav plate is nearly 2.5" above the bottom of the transom and I have no probs with (cooling) water pressure or prop ventilation, but each boat/motor is different.

When trimmmed up you can actually hear the blades 'sucking' but there is no slip and I pick up the last 5 mph (and 300 rpm) running trimmed into the 'suck' zone ,as I call it for lack of better words!!

My boat calculates to less than 5% slip which is in the ball park for max performance. Average slip for light planning boats is 8%

I'll go and work yours out and post it here.....

Any idea what the reduction ratio of your outboard is and what the recommended max WOT rpm?

[Rod]

4 Blade ali prop will be spot on for your tub Brad.


Remeber these boats are only small and a 4 blader grips the water better than anything. 4 bald all the way