outboard jet impeller question

[redbull660]

I have a 2003 yamaha outboard jet 115 horse 4 stroke, I have an alluminum impeller and a stainless steel impeller. which one should I use. the stainless steel runs the boat at 4900 rpm and the alluminum runs it at 5400 rpm.

[stonebreaker]

Which one gives you the best performance?

[mrmoto58]

Hi how do you like your 115 yamaha .I have a 19.5 alumacraft and was thinking of going to a jet .the boat is rated for 100hp because it's a tiller .Befor I got the boat it had a 150 yamaha on it but i think that would be a lot to hold on to .Ted

[redtech]

stonebreaker is right wihch one give the best performance try them both but i think you'll end up with the aluminum. it sounds as if this one is allowing your engine to get closer to rated w.o.t.

[Loveofsea]

mrmoto58

i can assure you that 150 hp is not too much to handle with a tiller. The problem is they don't make a tiller handle for a 150. But, i'm sure that you could adapt their tiller to the 150 with a little effort.

Why would you do to a jet and loose all that performance??

[mrmoto58]

Hi to loveofsea .I'm new to this site and loving it already .people to talk to about boats .on jets my dad in the 7o's build jet boats with small block fords and they worked great the safty is great for kids .the water at the lake i fish has been 2.5 ft low for 2 years this year it could be lower .Boy have i found rocks that i didn't no were thier lol .I call the lake bottom end lake now.but outboard jets i don't no vary much about and the last think i won't is to have a suckout boat .alumacraft are a vary heavy boat .Thanks for input.ted

[ondarvr]

On a 115 the Aluminum one will most likely work better, you need 150hp+ to see much improvement from a SS impeller. I'm not sure the recommended RPM range for that engine and didn't look it up, but 4,900 RPM would seem pretty low.