WOT RPM......?????

[jgm7739]

I'm looking into purchasing a new ss prop. I currently have a 19 pitch ss prop. Right now my wot rpm's vary between 5200-5500. Even under the same conditions, me being the solo passenger, the rpm's will vary as stated. SHould I stick with a 19" prop move to a 17" to bring the rpm's up a bit.<br /><br />I believe the recommended wot range is 5500. The 'redline' on the tach reads 5500 as well. Would it be advised not to exceed that range when under full throttle and tring to trim the engine.<br /><br />Thanks

 

[KennyKenCan]

Re: WOT RPM......?????

Hey jgm7739,<br /><br />5500 RPM is the recommended WOT.<br /><br />I have run my '94 Merc 135 at 5800 RPM at WOT without any problems, although I am not recommending that you run the engine this high RPM.<br /><br />What diameter is the prop?<br /><br />14 inches / 14.25 inches / 14.5 inches?<br /><br />Is it a wide blade model or a narrow blade prop?<br /><br />This all makes a difference in performance.<br /><br />Selecting the correct prop is probably the most difficult part of tuning an engine to perform the way you want.<br /><br />There are many options.<br /><br />See if you can find a local dealer who has test props available so you can try different props until you find one that suits your boat and habits.<br /><br />Kenny

 

[jgm7739]

Re: WOT RPM......?????

Diameter...unsure, I'd say 14"??? It's a 155 Yamaha.<br /><br />And also would speculate it is a wide blade on the prop.<br /><br />Like you said, I'm looking to maximize performance. I know the boat is not a rocket, but I want all I can get. I use it predominately for water skiing and just cruising.

 

[jgm7739]

Re: WOT RPM......?????

sorry, 115hp yamaha<br /><br />NOT 155

 

[KennyKenCan]

Re: WOT RPM......?????

Hey jgm7739,<br /><br />Props are not judged strickly by the pitch.<br /><br />It is the combination of pitch, diameter and blade configuration that give results.<br /><br />To determine the diameter, measure from the center of the hub to the end of 1 blade, then multiply by 2.<br /><br />Like I said earlier, you should try to find a dealer that has loaner props, and try different ones.<br /><br />That is really the only way to determine which prop will work best for your application.<br /><br />No two boats or motors are the same.<br /><br />What works well on a friends boat, may not work at all on your boat.<br /><br />Boats are like women, no two are the same. <br /><br />Kenny

 

[jgm7739]

Re: WOT RPM......?????

GIDDE UPP KENNY!!!<br /><br />Now, how should I find a dealer that has loaner props........the yellow pages??<br /><br />Thank god, one woman like mine is enough!!!

 

[Dhadley]

Re: WOT RPM......?????

The best place to hook up with is a performance center. They will arrange a test or may already have a recommendation on a style / make prop based on what you have now. Once you buy one they should extend an exchange deal within a given period of time (say 48 hours) as long as the prop can still be sold as in new condition.<br /><br />Thats the way we do it anyway. If we can be of any assistance please dont hesitate to let us know. E-mail if you like to dhadley50@aol.com.<br /><br />Good luck!

 

[KennyKenCan]

Re: WOT RPM......?????

Thanks Dhadley,<br /><br />I was not too sure how I was going to answer jgm7739's question as to where to get a loaner prop.<br /><br />I know where to go here on Long Island, but I don't have a clue where to find a loaner prop where he lives.<br /><br />Kenny

 

[Dhadley]

Re: WOT RPM......?????

Yeah, loaners are a tough deal. We like to arrange a test session so we can regulate what goes on and where. We have found that if it's explained properly in the begining it's not a problem. <br /><br />When someone wants to exchange a prop within the given time, I just ask them if they would buy it at new prices. Everybody says yes. Then I ask them if they would sell it to their best buddy at new prices. That will tell us what condition its in. <br /><br />Most everybody understands. Every once in a while we get a guy who wants to return it after a week or even a month. Fine, but not as new!<br /><br />As the world.....I mean prop... turns!

 

[Bear]

Re: WOT RPM......?????

yamaha 115 hp<br />4500-5500 rpm<br />1730 cc