Newbie propeller question - 252G

[BostonHack]

Hi,

I'm new to boating and I just bought my first boat, a 1989 252g Sailfish. The props look like they're 14.5" x 15 and are a little banged up and "can't be reconditioned". At WOT, one 200hp engine spins at 5900 and the other at 6000 (I read they're supposed to be at 5500).

Someone in town is selling a pair of reconditioned 13.75 x 17 black stainless for $100. It sounds like a great deal, but don't know if I should be looking at new props for $700 (and don't know what to get if I were)? With gas prices being what they are - I'm looking to minimize fuel consumption.

I welcome any and all advice.

Cheers,

John

 

[BobP]

Welcome! Nice boat, the legendary "Sailfish". Plenty of other members with late 80's Sailfish.

What engines do you have?

The WOT range for 2 strokes is under 5500 usually. Between 5000 and 5500, the closer to 5500 the better. Others can correct me.

Are your two props alum or stainless?

 

[Grog]

15's are too small of a pitch for you. For a $100 grab the 17's (they are a pair of counter rotating?), it'll get your RPM's down to around 5500-5600 and give you better milage too.

 

[BostonHack]

Welcome! Nice boat, the legendary "Sailfish". Plenty of other members with late 80's Sailfish.

What engines do you have?

The WOT range for 2 strokes is under 5500 usually. Between 5000 and 5500, the closer to 5500 the better. Others can correct me.

Are your two props alum or stainless?

Thank you for the comments. I've been reading this forum now for two weeks and have gotten lots of good info. I'm sure I'll be a regular reader.

She has 1988 200hp ETXG 2-stroke engines (on a 1989 boat..? "She came that way...") My current (and prospective) props are stainless and are LH/RH if that helps.

I did read it should be 5500 or under... and am wondering how much the smaller, but higher pitched props would buy me. Another post mentioned "get the largest props you can" (I don't understand the reasoning) and was trying to determine the tradeoff of smaller diameter vs the increase in pitch.

 

[gw204]

My guess is the 13.75" diameter props won't move enough water to really make a difference. I would look for either 14 x 19 or 15 x 17.

 

[BobP]

Brian has the ticket.

I wonder how long it would take you to make up the 700 bucks in fuel savings! See if you can cut a deal with the seller, if you can try them out to see if they work out, if not - he agrees to return $650. He makes 50 bucks, one day loan.

Alternetaly, all you have to do is stay below 5500 RPM to protect the engine from over rev-ing. The engine proped as is will give you great torque to accelerate like a bat out of hell, top speed will be limited, and fuel efficiency will suffer, until the time you find suitable used props.
You didn't mention any unusual vibration back there, if so, replace the props the sooner the better.

 

[TBone]

:idea: .......to add to that, I believe we talked about this one before.

Correct me if im wrong, but you want that 5500 rpm WOT on the boat

being loaded, fuel, water, gear, passengers?? If you test the props with an empty

light boat and max @ 5500 rpm WOT, you may not meet that with a loaded

boat, thus putting unwanted stress on your motors and causing them to lug.

So if you get over 5500rpm on an empty boat, that may not be out of the realm.

Guys????? :?: