How much will a dinged up prop affect wot. Need wot baseline for new prop order

[Sharps-Nut]

I have a 165 hp mercruiser io based on the 250 gm inline six cylinder. The prop that came on the boat is a 19 pitch and boat turns 4000-4100 at wot traveling 40mph. Thanks to you folks help I now realize that this is lugging the motor. Someones earlier post suggested that I should crank up to 4400 with this combo in wot. The prop is badlt dinged up The edges of this prop look like they were chewed on by beaver then the edge finished up by some sorta cruel ball pein hammer work. The edges measure over 1/8 think in places. There are several chips gone, one as large as 1/2" by 1" long. Will this old battered prop achieve wot for me. What prop do you think I should order as far as pich goes? The boat is a 1977 caravelle 18-1/2 foot trihull. The plans are for tubing and cruising in a fresh water lake. Open to thoughts as to what pich to start with. Or of you know tell me so and I will trust your opinion.

 

[Doug Durako]

Re: How much will a dinged up prop affect wot. Need wot baseline for new prop o

Re: How much will a dinged up prop affect wot. Need wot baseline for new prop o

I had the same motor in a 1976 18-foot Cobalt.<br />Use a 17 pitch to pull tubes, 19 for just cruising. You are not lugging the motor--top end for that motor is 4200 rpm. With a Stainless prop, you might hit 43 mph at WOT. Don't run a banged up prop at WOT!<br /><br />Borrow a stainless 19 and start from there for your baseline.

 

[BF]

Re: How much will a dinged up prop affect wot. Need wot baseline for new prop o

Re: How much will a dinged up prop affect wot. Need wot baseline for new prop o

From how you describe the damage, I take it your current prop is aluminum. (?) Why not take it to a good welder/prop shop and have them fix it for you? Aluminum prop's can be made as good as new by a good shop (and is cheaper than buying a new one). Then you'll know where you're at rpm-wise with a good 19 pitch. Maybe then you'll wanna get a 2nd prop of a different (lower?) pitch for tubing, and as a bonus you'll have a spare. <br /><br />Anyway, that's my $.02<br />Good luck.<br /><br />Brent

 

[POINTER94]

Re: How much will a dinged up prop affect wot. Need wot baseline for new prop o

Re: How much will a dinged up prop affect wot. Need wot baseline for new prop o

Sharps,<br /><br />FWIW, I cannot caution you strongly enough against running anything but a near perfect-perfect prop. Harmonics created and transmitted up your drive can create real expensive issues. You will wish you popped the bucks for a good prop when you get that repair bill.....

 

[DJ]

Re: How much will a dinged up prop affect wot. Need wot baseline for new prop o

Re: How much will a dinged up prop affect wot. Need wot baseline for new prop o

Sharps-Nut,<br /><br />That engine does not like anything over about 4300. It doesn't mind being run in the 4-4300 range.<br /><br />Get that dinged prop off of there. It's not doing your lower unit any good.<br /><br />If you drag a lot of toys around, I would put a 17" on. Otherwise, you're not lugging it with a 19" This engine, as stated above is not a real revver.

 

[Sharps-Nut]

Re: How much will a dinged up prop affect wot. Need wot baseline for new prop o

Re: How much will a dinged up prop affect wot. Need wot baseline for new prop o

Thanks for all the replies. I felt 4000 was all a inline buzzen half dozen needed, this being based on car experience. I took the boat out once last fall after the purchase thats how I knew the performance specs of the boat and prop as is. We ran it for maybe a hour or hour and a half. Now its spring and being new to the field I am trying to prepare for playing this summer. I don't know beans about a prop so I thought I'd ask before buying the wrong pitch. I priced having the old prop rebuilt. They priced it at 75.00 if it didn't need rehubed and 125.00 if it did. The owner of the shop felt it would need hubbed. Thats why I thought I'd put it under the seat as a emergency prop and replace with a hustler. I am going to try the 19 pitch. Thanks for keeping me straight. Sharps-Nut