Prop Mfg suggestion?

[rothfm]

Bit of a long read, trying to include as much facts as I can.....I have been researching

I dont know enough about diff prop makes/models, so I thought After researchinging these forums, i would toss out some info, see your thoughts.

I have a Neptune/OMC 202 with 1993 140 looper 25". Thats a smallish 20 walk-around cuddy.

I run In MA Saltwater bays and offshore exclusively. I run 90lb Smart tabs.

Dont know hull weight, possibly 2200, plus motor, 70gals, lots of gear, ice (dam I need a higger boat!) I carry alot

I use an OMC 15.5 X15 Alum prop. I run at top end of WOT Rpm range which is 5500-6000, in fact I can get to 6100-6200 (but dont run that hard)

Overall good holeshot, decent acceleration, however, it takes alot of rpm to maintain a decent cruise, like 5000. If i drop to 3500-4000 It may start to slowely dropp off Plane. At Wot I see only 28-29 mph or so(guage and gps)

I now realize my tabs are at thier "strongest" adjustment setting as They spray way to much water all over the place. Going to test different adjustment holes, and lift them totally up temporarily.

Oh, i have the motor on the higher mount holes and also trim up. The leg is s not too low.

From reading, seems im under-propped. I feel a 19p would be a dog for me. Was thinking a 14 7/8 or 14.5 in a 17pitch Stainless(reduced flex) might be a good fit. Seems I can afford to drop a bit of rpm and be in-range without Lugging.

I just not sure about the characteristics of diff manufactures/modle and what they can do in this size....like Lift, low-end vs hi-end performance etc

My main goal is mid-range cruise performance& economy, as well as a slow troll. Very seldom can I run upper ranges due to conditions

Curious what the knowlegable folks here think?

 

[jimmbo]

If you are running 6100 - 6200 and the WOT range is 5000 - 6000 and the tach is accurate, you are under propped. Being that is a big boat for a 140, in this case I might suggest a 15" pitch 4 blade prop, It won't help your top end any but may carry the load better at your cruise speed.

 

[rothfm]

Thanks Jimmbo,

Yes, manual states 5500-6000 and im more than there

I was researching 4 blades, some seem to think they help at high speeds such as 50+ on performance boats

But also read about the added blade helping maintain low/mid cruising sppeds with addtl load.

Seems to make sense. Im not really into speed per sey, just a better slow and mid-cruise without running 5k to do it. Seems like overworking and sucking fuel to basically stay on plane

I have a pair of older 150's, I may use this winter to rebuild one for this boat.

Really think the 150 would perform better, and be similar to consumption as the looper 140

Thanks for the advise.