Prop ID And ? attn. Walleyehed

[KYHunter]

I have a aluminum prop on my '78 Johnson 115 . I cant find the size and pitch numbers but these numbers I can still read 496 335 / C and 118 177 1 . Do these tell what the size and pitch are? The guy I bought boat from (he never ran it ) gave me another prop he said came with the boat . It is 12 3/4 x 21 , and has the following numbers on it 384 ? 02 cant make out 4th # and 63 54 5 SN also a big M with a circle around it and is S/S. What kind of prop is this? The boat I have the motor on is a 15'6 Procraft 1978 bass boat. With the one thats on it now I was getting 5300 at WOT that was before my tach died I have a new one on the way. I know I need to know my rpm's to get the right prop . I just thought maybe some of the prop experts would have a recommendation. The boat comes out of hole great and rides great at all speeds will trim and ride on plane down to 10-15 mph . The only question is top end was told used to get 60 mph.<br /> Thanks,<br /> KYHunter

 

[Goodoleboy]

Re: Prop ID And ? attn. Walleyehed

Some props have the dia. and pitch stamped into the rubber hub.<br /><br />You will have to take prop off to read it.<br /><br />Good luck!

 

[KYHunter]

Re: Prop ID And ? attn. Walleyehed

I had prop off and cleaned it trying to see numbers - letters etc. The numbers in my post were the only ones I could make out . <br /> Its the one that that I'm using now that I'd really like to know the size and pitch . <br /> Is there a way to figure out the pitch ? I can measure for the size.<br /> Thanks,<br /> KYHunter

 

[walleyehed]

Re: Prop ID And ? attn. Walleyehed

The SS prop with the M in the circle is an OMC SST1, I believe. As for pitch, the numbers you give don't jive with my listed P/N's...<br />If you know the other prop is a 21 pitch, when you get your tach, run the 21 and get some numbers and we can go from there.

 

[KYHunter]

Re: Prop ID And ? attn. Walleyehed

Thank You, Walleyehed . I hooked up my new tach today . As soon as I get to lake and run it I'll post results.<br /> KYHunter

 

[KYHunter]

Re: Prop ID And ? attn. Walleyehed

Walleyehed, and everyone , <br /> I ran the boat today and was turning 5100 rpm's at WOT. I somehow got things screwed up , the prop I ran today and that was on the boat is the aluminum one with these numbers : 496 335 / C and 118 177 1 . I cant make out anymore I have taken it off and cleaned . I cant find any on the hub, the above numbers are in the area between the fins. I need to know the pitch so I know what to do next. How can I find out the pitch for this prop? <br /> Thanks,<br /> KYHunter

 

[KYHunter]

Re: Prop ID And ? attn. Walleyehed

Walleyehed , <br /> I was able to make out numbers on prop today. The one I ran yesterday was a 13 X 19 . Please read above post about rpm's . Is this good enough ? Or do I need to try to get the other 400 rpm's, to reach my motors peak rpm's? There's probably a little discrepancy from tach to tach right? I haven't been able to compare it to another tach yet. Any recommendations ?<br /> Thanks,<br /> KYHunter

 

[G DANE]

Re: Prop ID And ? attn. Walleyehed

You would be even better off turning 5800-6000, especially if you were alone on boat, RPM's will drop as load in boat rises.

 

[KYHunter]

Re: Prop ID And ? attn. Walleyehed

OK, Does that mean the recommended rpm's for my motor are void ??? If so , Why ? different gas now-a-days ? Just curious , I thought I was supposed to go by the 4500-5500 rpms on the plate on my motor . What should I do first to get to the 5800-6000 figure? I've read some archives as to set-up , and I believe,going by this that my boat is set up correctly. What diameter , pitch should I try first? Wouldn't a 2 inch lower pitch change amount to 600 - 800 rpms? Please let me know I am going to lake mon. and need to borrow a prop to try.<br /> Thanks,<br /> KYHunter

 

[G DANE]

Re: Prop ID And ? attn. Walleyehed

What I meant to say is that this motor does best and has the highest output between 5500 and 6000. If your boat is loaded with people and gear and you get down to 4500, you start logging motor. It will like exceeding 5800 and running at 6000 with light loadnow and then much better. Thats why most recommend to prop for highest target RPM's, or raising motor to make it possible to get there. If you can borrow a prop, try going down to 17 and the motor will perform more, and gain RPM's by itself.