9.9 prop recommendation

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Holdemhook56

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I used the prop calculator and got a recommendation of exactly what I have now. 9 1/2 x 10. Here is my situation. I have a 1959 14' v hull feather craft boat. 6 gallons of gas 2 batteries 2 10lb anchors, trolling motors 2 small coolers and probably 20 lbs of fishing gear. I myself am about 220. I run the batteries and tank up front and use the boat primarily by myself. The 1982 evinrude 9.9 pushes me about 16 mph. Perfect to me. When I put my 240 lb fishing buddy in the boat I run about 10mph. I don't even mind that so much but I spun the prop hub and need a new one. My thinking is (since I have no way to tell rpm) that obviously I'm turning way less rpm at 10 mph under a big load than 16 mph solo. I know lowering the pitch will lower speed, but wondering if the lower pitch will get my rpm up under the heavier load, Producing more hp, and may even pick up more speed. Since I have to purchase a new prop I'm concidering a 9 pitch instead of the 10 I have now. I know that may not be enough technical info to go on but I know a lot of you guys have enough experience to make a good judgement call. Any thoughts!
 
You can find a cheapo induction tachometer on Amazon for <$10 which will give you your RPMs in both cases. You don't want to go dropping to a 9P only to over-rev your motor when you're out solo.

I'm really disappointed now in my setup if you're able to get a similarly sized boat up to 16mph on a 9.9 in a V-hull and I can barely do 23mph solo with a 25hp in a 14' flat bottom dropping to 19-20 mph with a companion. Finding the right prop is a PITA.
 
I'm also looking for a New prop for a 9.9 two stroke pushing a 1448 Jon.

The stock prop on allot of 9.9 four stokes is 9.25x9.

That's what I am going to go with. Is rather be too short on pitch that to tall.
 
onthewater102 said:
I'm really disappointed now in my setup if you're able to get a similarly sized boat up to 16mph on a 9.9 in a V-hull and I can barely do 23mph solo with a 25hp in a 14' flat bottom dropping to 19-20 mph ...
Flat bottom vs. V-hull ... the flatter and larger full-'wetted' surface is what impedes your performance ... Maybe raising the bow somehow to reduce it could be of some help.
 
After decades with a least 11 boats and working for a marina and two manufactures I pitch and tweak everthing it for absolute max speed at first. Every motor has mods or tuning tips on the forums. Example your 9.9 can benifit from the 15hp parts if you want but at least get it running and jetted to perfection. I raise the engines with wood shims, sand off the ruff bottom, file all knicks in prop and skeg and move weight around by the ounce. Now I'm close and am not leaving anything on the table. Next drop the engine mount down one hole or shim and drop the pitch by 1". Now instead of seeing if I can get that last mph I can jump on plane and it holds cruise RPM much more steady. With the engine a little lower I can trim a lot more before it ventilates. That gives the ability to trim up more to compensate for different loads and conditions. With out the highest pitched prop working the engine so hard the fuel usage is way less. Speed prop can burn a tank in 3 hours. The correct prop can run all day if I stay out of WOT. In a perfect situation my speed prop runs near the lower end of the recomended WOT RPM. My everyday prop runs near the top.
Re read that ^ and the excellent tips above if that's not a basic understanding. Your little 9.9 is no different and you were already given excellent advise. My guess is that 9.9 will like a 9" but remember this. If you go slow or troll most of the time you can run 50:1 oil ratio. If you wind up screaming that engine near the max WOT then more oil is better. I settled on 40:1. The racers run 25:1 and the EPA wants 50 or even 100:1 on some new stuff. I put in too much oil then incrementally back off the amount until it's just to the point of not smoking too much. More oil is more compression, power and engine lube. Measure perfectly. Highest Hp on a two stroke is 16:1. Problem is it will foul. Find your happy place.
 
jy951 said:
I'm also looking for a New prop for a 9.9 two stroke pushing a 1448 Jon.

put a 40, 50, or 60 HP (or bigger if you have the balls) and be done with it!!!!
 
ACAMS said:
jy951 said:
I'm also looking for a New prop for a 9.9 two stroke pushing a 1448 Jon.

put a 40, 50, or 60 HP (or bigger if you have the balls) and be done with it!!!!

Yeah I would like too but this is mostly for a small river and I tend to hit things now and then. i am more limited in speed by my nads than motor.
 

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