Selecting A New Prop Size

[squidboy]

Fishraiders,

Well I have finally downgraded to a 4.2 brem boat with the Suzuki DF50 motor. My only concern to date is that it does not seem to perform as well as my Honda 40 HP runabout. They both do 30 knots on the water and the Honda pushes a run about which is much heavier and bigger than the Outlaw and mind you I have had four people on it versus just me on the bream boat. I was just wondering what sort of speed you would gain any other similar boats and what size prop you are running. I am considering running one size up prop in stainless (being a 14 inch prop, in comparison to the current 13 inch alloy prop) to see whether it would make much difference. My only concern is that I may be putting the wrong strain on the motor even though it can be rated all the way to an 18inch prop. Would love your thoughts.

What I would like to achieve is a little over 20 knots at 4000 RPM to run the engine at a lower RPM and save a bit of fuel (Possibly).

All thoughts would be appreciated.

Cheers

Marco

[rickb]

Hi squidboy,

give huet a call he will tell U the prop you can use with that motor

I changed mine to a bigger pitch,as My fibreglass was a bit slow off mark,now I gun it and she climbs

straight over the breakers off beach.But revs out real quick as well.

PM huet marine.

[a boat]

Hi Marco, first you will need to know your WOT RPM with the current prop and if you want more acceration going up in pitch will make that worse and could cause the engine to lug badly. Get the WOT RPM and we can go from there.

Cheers,

Huey.

[squidboy]

Huey,

I must be silly but what is the WOT RPM? My top RPM is about 6500 with the rev limiter.

[squidboy]

Huey,

I finally found the WOT RPM, I have the DF50 model.

SUZUKI OUTBOARDS

HP/Model WOT RPM Gear Ratio

DF50 5500-6500 2.09

[a boat]

Hi, WOT means wide open throttle and are you saying you are doing 6500RPM and hitting the rev limiter, if so you are underpropped and you could not go a lower pitch prop to get better acceration if that is what you are wanting to achieve. What pitch prop is on there at the moment and the dealer should of not fitted this prop because to hit the rev limiter you have the wrong prop on, but as i said if you want more "get up and go" you will not get it with this engine if you are now seeing 6500RPM and you might need more HP or another brand of 50HP outboard that we like that offers better performance but still are clean and fuel efficient.

Cheers,

Huey.

[tuffy]

Marco, I am going through the exact exercise at the moment. Upgraded late last year from a Honda 40 carby to a new Honda 50 injected. Oddly, the new 50 came with the same size prop (11 1/4 x 13) as the old 40 and I was getting a lot of ventilation, Purchased a stainless prop from Solas the same size and it fixed the ventilation problem but I was revving out to 6500 WOT and only hitting about 29 knots, pretty much exactly where you are with yours. WOT on my Honda is 5500 to 6000 rpm. Contacted Solas and they willingly exchanged it for a 14" which I only got this morning, so I will be keen to see what the difference will be. Like you I was revving to about 4800 RPM at about 19knts so I reckon I was underpropped. The guys at Solas are extremely helpful and are quite willing to give you sound advice over the phone.

Unfortunately I will not be able to test my new prop until next weekend ( working until then)and will post results as soon as.

Cheers, Tuffy.

[squidboy]

Tuffy,

Now you are a man! I too have a Honda 40 carbby and it is a screamer in comparison to the Suzuki 50. Mate, would love to hear how you go, I am looking at testing once again next weekend as I have to write down my WOT. Could ou send me Solas details of where they are etc?

Cheers, would like to ring to speak to you sometime if you want to compare notes.

Marco

[Dangas]

Hi Guys

I am a Honda man too. I got a BF30 on my 4.2 centre console and i love it but holeshot performance with the standard prop is a bit weak. I have problems with speed when the boat was fully loaded with 3-4 people it wont go past 5000rpm. Ive just ordered a Solas prop with a different pitch and currently waiting for it.

Just go online and search for them you should be able to get a phone number from their website. They were very helpful and put me in the right direction. I cant wait to put it on the boat and test it out.