Help with tweaking performance

I have a 2002 Yamaha 2 stroke on a 15.5’ GlasStream bass boat. The bottom of the hull is in decent shape for the boats age.<br /><br />With 6 gallons of gas, three batteries, tackle, and me in the boat it is running 39.7 mph GPS. The motor is running at 5900 – 6000 RPM’s WOT with a 17 pitch prop and 2.33 gear ratio (12:28). <br /><br />Yamaha recommends an RPM range from 5000 – 6000 RPM’s.<br /><br /><br />I am happy with the speed and handling but was thinking about trying a few other things to tweak the performance. <br /><br />Would it be a benefit to go up in prop pitch ( 19 – 21 ) and lower the RPM’s and still have motor reliability. <br /><br />Would the use of a Bob's Machine jackplate help with performance? They have a jackplate that adjust from 2.5 – 5” of offset. <br /><br />This boat is strictly for fishing (tournament and recreation) so I am not worried about pulling skies/tubes and such. Just getting to the fishing spot which can be several miles away in a timely manor. <br /><br />Thanks,<br /><br />bKelly

Re: Help with tweaking performance

OK, whats the HP of your engine, where is the vetalation plate in reference to the bottom of your boat now, is your present prop aluminym or stainless? Lets get you to at least over 40 MPH.<br /><br />The last 15' Skeeter I had with a 75 Evenrude ran allmost 50 MPH.

Re: Help with tweaking performance

Lube- I love your lure, but I thought for sure you'd have an oil can or something like that!!(Sorry for the interuption bKelly)

Re: Help with tweaking performance

Sorry I thought I had it in there…<br /><br /><br />It’s a 2002 Yamaha 70 HP.<br /><br />The plate is probably 1” or so below the pad. I will try to check it this afternoon. I am sure it needs to be raised some…<br /><br />The prop is a Power Tech 17 pitch 13 ¼” stainless steel performance prop with cup. With the current set up I can run with the trim all the way and the prop won’t blow out at all.

Re: Help with tweaking performance

I would also like to add that hole shot and midrange is strong. I haven’t timed how long it takes to get on pad but I would say around 4 – 5 seconds or less. From 2600 – 4600 RPM’s it responds quickly to changes in the throttle. I would say that the boat loaded for a tournament is around 1200 - 1500 pounds.<br /><br />It runs flat with 2/3 or more of the boat out of the water. It doesn’t have and problems with sliding, porpoising, or chine walking.<br /><br />I know that increasing pitch will require more time to get on plane but will a set of smart tabs help get the boat up quicker and allow the boat to take advantage of the extra pitch. <br /><br />If I am dialed in that’s fine but if I can still get a little more in the top end (mid to high 40’s) and not suffer too much on the bottom end I would like to know what are some things I can do…

Re: Help with tweaking performance

You need to raise your engine about 2 ". With that raise, you will need to go to a 19P Prop and posibly a 21P. With Smart tabs you will be able to spin a 21P Im sure by yourself, not sure with two, that would have to be tested out. I have the Smart Tabs on my Bass Boat and it jumps on plane and will plane at 15 MPH which is nice for the wife and going through chanels and such. With the tabs, prop change, and raising your engine, I would think at least 45 MPH would be posible.<br /><br />To address your question about a Jack Plate, they nearly allways help with performance, Now that I am used to the performance of my boat Im thinking of one for mine. Im watching Ebay, I guess Im more of a speed freak than I thought. Also thinking about a foot throtle.

Re: Help with tweaking performance

Thanks LubeDude<br /><br />The lower plane speeds would be nice. I run a lot of small creeks and such off of main river channels.<br /><br />I also want to make a few 90's sweat a little harder. I am already on their tail and I can beat them on the start.<br /><br />45 mph would be great...