# Conchfish 16 w/ 2-stroke 40hp Yamaha



## neueklasse (Dec 25, 2019)

What’s up guys. I picked up a 1997 40hp Yamaha for my Conchfish 16 build. Engine runs great I cleaned the carbs today, it idles perfect and starts instantly. It didn’t come with the correct prop/stock one. I’m looking at matching it up with one. Any suggestions? I’m pretty green when it comes to prop pitch and sizing. Thanks.


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## flyclimber (May 22, 2016)

@bryson i believe is running a 40. He may be able chime in. Great looking conch!


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## bryson (Jun 22, 2015)

I was running a Yamaha 2 stroke 30hp on my 17.8 before I made all my changes (now running a 50hp Tohatsu). I didn't experiment with props, just ran what was on the motor when I bought it -- according to the stamped part number, it is a Michigan Wheel 10-1/8" x 14P aluminum prop. I think that I was seeing around 30 mph top speed, maybe a hair more.

It's a little different of a setup than yours but it might help you narrow the search. Good luck and sweet looking skiff!


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## neueklasse (Dec 25, 2019)

flyclimber said:


> @bryson i believe is running a 40. He may be able chime in. Great looking conch!


Thanks!


bryson said:


> I was running a Yamaha 2 stroke 30hp on my 17.8 before I made all my changes (now running a 50hp Tohatsu). I didn't experiment with props, just ran what was on the motor when I bought it -- according to the stamped part number, it is a Michigan Wheel 10-1/8" x 14P aluminum prop. I think that I was seeing around 30 mph top speed, maybe a hair more.
> 
> It's a little different of a setup than yours but it might help you narrow the search. Good luck and sweet looking skiff!


Sweet thanks man I’ll look online for something similar. I follow you on Instagram this is Josh @whatsmydepth. I was originally looking for a short shaft 30 and came across this 40. Figured they’re similar enough in weight/power.


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## kamakuras (Feb 23, 2012)

On my CF 16 I had PowerTech SWC 3 14p with Tohatsu 50. Excellent prop especially if you are going with a jack plate. It really shines at high elevation. Top speed was 36. I think 5600 rpm. Hole shot was instant. You would probably be better off with 12p in that prop. If you aren't worried about running elevated the SCB 3 would also be a great match for the CF and probably slightly faster. It doesnt have the heavy cup of the SWC and slightly less diameter so you might be good with 13-14p. Whatever you do get a tiny tach off Amazon. The real one, the imitations dont work for crap. You want a prop that is running in the recommended RPM for your engine. Light load full throttle it should be on the high end of the max RPM you engine is rated for. Hope that helps.


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## bryson (Jun 22, 2015)

@neueklasse yes, been following your progress -- she's coming along nicely! I really like the big tiller with the shifter (mine was the small one with the shifter on the lower cowling), and I don't think the 40 weighs much more than the 30. That should be a great motor for the skiff.


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## neueklasse (Dec 25, 2019)

kamakuras said:


> On my CF 16 I had PowerTech SWC 3 14p with Tohatsu 50. Excellent prop especially if you are going with a jack plate. It really shines at high elevation. Top speed was 36. I think 5600 rpm. Hole shot was instant. You would probably be better off with 12p in that prop. If you aren't worried about running elevated the SCB 3 would also be a great match for the CF and probably slightly faster. It doesnt have the heavy cup of the SWC and slightly less diameter so you might be good with 13-14p. Whatever you do get a tiny tach off Amazon. The real one, the imitations dont work for crap. You want a prop that is running in the recommended RPM for your engine. Light load full throttle it should be on the high end of the max RPM you engine is rated for. Hope that helps.


Thank you I’ll look up some sizes and see what I can find. Beryllium is looking good!


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