Prop Pitch

[ebexp2000]

I have a 2001, 16.5 ft Sylvan Excursion (aluminumboat), with a 2001 90hp 2stroke Merc. The boat holds 21 gal of gas, three batteries, trolling motor, 15hp 4stroke kicker (soon), gear, and people. There is quite a bit of weight in this boat. It's also a fairly wide boat.

I currently am running with an aluminum Merc 19" pitch prop, and I can bring it it about 47 mph. I can get it going faster, but my motor exceeds 5500 RPM, which is the max RPM. It planes really quick, and gets to 5500 RPM very fast. The hull is rather Deep, and the motor is down as far as it goes, with the cavitation plate lining up just below the bottom of the hull.

I'm looking at Merc Laser II SS props. I know that a 19 SS would probably be a waste of money, so I'm wondering, would I go with a 20" or 21" SS Laser II Prop? I still want a good hole shot, and the ability to carry quite a few people and gear in it, while still maintaining speed. What do you all think?

[Dutchman]

This is a fast hull. I would try the 19" Laser II, the extra bite a stainless provides may get you into the right rpm zone. In fact I would try all of them, just because I like doing things like that. The Laser II is a great prop for this style of hull. I run a Laser II 21" pitch on my Sylvan 2000 Eliminator with a 150 Mag III Mariner, full tourney load and 2 big guys gets around 50 - 51 mph gps. I tried several and the Laser II gave me the best hole shot and near best top end. Most of all have fun while tweaking out your boat....


" Fishing is the pursuit of what is elusive but attainable, a perpetual series of occasions for hope "

[exexp2000]

I forgot to say, we would like to get a little extra speed. What happens now is that our motor can be tilted up, but the prop starts to cavitate.

[Gary Gray]

If you check with your local dealer, they have a loaner prop program, which will allow you to test props, to see which is the better for you. After reading your post, I would start with a 19 pitch Tempest II, get where your RPM's are at about 52-5300, and you will find your speed to be more stable with this style of prop.

Hope this helps,
Gary Gray #10

[MarkG]

I had nearly the exact same setup on an 88 Lund with a 90 Merc.19p aluminum gave me 5500-5600. Had a 20pitch LazerII also. Same RPM range about 3-4mph better. I believe if you replace your 19p aluminum with a 19p lazerII your RPM will be off the scale. It will raise it too high. Go with the 20P LazerII