I was talking to Brent at Performance Marine today and he mentioned that a lot of guys who go to Powell use a differently pitched propeller than they use on the desert lakes because of the 2000 ft+ elevation increase of the reservoir. It looks like Powell ls at 3,500 ft El +-.
Have any of you experienced that? He said it's a good idea to go down 2 numbers on the propeller.....supposedly to make up for the decreased amount of oxygen thereby allowing the outboard to get up to RPM and assisting the watercraft to get on plane. My boat gets on plane in about 5 seconds around here. I'd like to hear comments from the Powell veteran walleye slayers. I'd hate to get up there and struggle with that.
I'll mention that Performance Marine didn't have a prop to sell me.....it was just a cautionary type discussion.
My take on this - Brent is correct about the lake elevation vs prop pitch. It can & does have an effect on engine performance. And the current lake elevation is about 3591'
So with my 175 Opti w/ a Merc Hi Five prop, while I my have (none that I can remember having anyway) slight performance issues it's certainly not anything that I am or have even been concerned about. For me, the slight struggle to get onto plane is certainly more noticeable on Lake Mary than what I remember at Powell. Now every boat/motor/prop setup is different and, for me anyway, at this time I don't see the need to go out and buy another +$500 or so prop just to gain a couple seconds hole shot or a couple MPH.
Now I can understand the need if you are going to travel a long distance and fuel mileage/fuel burn is important such as going to Good Hope Bay. And if I were to go to Powell more that just our one time a year maybe then it'll be something I would research more.
I have to agree with Larry here. I really don't notice much change with my boat from here to there. I have a 150 four stroke with a 19 pitch Tempest. My prop is ported, which I could play with up there for the hole shot.
Yes I noticed a big difference on my old 150 evenrude oil inject back when I had by bass boat, but I had both tanks loaded with fuel etc. but there was a definite performance drop off at Powell (in fact at times buddy would have to crawl up on the front of the boat and darn near hang over the front) to get up on plane. Steve if you are going to load up with fuel and other supplies you might consider a smaller pitch prop you won't have top end speed the same? Had the same issue at lake Mary.
We usually pitch down when we go up but I notice more issue with performance on the amount of weight we have in the boat for 4 days of camping than I do the prop change. Another reason is hazards aren't marked so the prop we pitch down with is aluminum.
Those are all good observations. I'm going to prop down, keep the new prop in the box and use if the Tempest 25 wont haul the mail.
Thanks.