I recently purchased a 1987 Basstracker Tournament Pro 17 with a 70 HP Yamaha outboard.  I'm very happy with the boat but wonder if it's giving me all the performance I can expect out of this combination.  With a full load (myself, son and grandson = 475 lbs)  plus rods, tackle, 9 gallons of fuel and full livewell my max speed is 35 MPH by GPS at WOT.  The boat planes well at 27-28 MPH at about  1/2 -2/3 throttle. The motor is turning a stainless Quicksilver Laser II  13 inch 20 pitch prop. Unfortunately I don't know what my RPM's are since the tach doesn't work (yet).

Thanks in advance for the input.

you will need to get the tach working before you can tell whether or not you are performing optimally.

You may need to change props depending on the load you are carrying. I would use two different props depending on whether I had one or two people in the boat that day.

You may be able to tweak another mile or two out of your set-up, but you're getting pretty close. Two friends of mine have Tracker 17.5' (Walk-Through) Targas (2000+ year ages) and they're both being pushed by 90 HP Merc engines. Top end speed for both is between 45 - 50 mph, which I think is pretty decent for the size and weight of this class of boat.

You do have electric tilt & trim, correct? With that, as you start to get on plane, you can adjust your trim to find the "sweet" spot. Of course, you also NEED to know your RPM's, so I'd get that taken care of right off.

My opinion is you're over pitched. I'd calculate you should be running a 3 blade 13.25 x 18 for that combo and load to run WOT into the upper end of the power band for that motor. You might see a 2-3 mph increase, but that's about it. Certainly would boost your holeshot, and maybe a little better response in the mid-range rpm's. Only way to tell is to borrow and try a couple of different props to find what works best under the predominant conditions you run.

My boat is an old (1977) Glastron Sportster (16') with an even older (1967) Evinrude 80hp. With my partner and all our gear my top speed is 35 mph running with river current or a tail wind. My solo speed with fishing gear is 40 mph.

First, 20" pitch prop sounds like way too much prop.  Get a tac and check your rpm.  I would think and 18 would be closer.

I too have a friend that has the 17' Tracker (about sever years old) with a 90 and 43 - 45 is about all he can get.  His starts proposing and beats your brains out above that.  He's tried about everything in the book and that seems to be the nature of his boat.  He checked with several others that have his same rig and they all said the same thing.

Thanks for the information.  Yeah, the repair of the Tach is one of the next items on my agenda.

I replaced the rectifier on my '87 70 HP Yamaha to fix my tach.  Wasn't too difficult.

I have a 15' Cajun Fish / Ski.  With 350 lbs of people and gear and 4 gallons of fuel I can hit just over 40 mph by GPS on a calm day.  I have the stock prop.

Do you happen to have the original manual for the Yamaha?

Just fish a let it alone and smile as you go past them fast boats  you are getting 5 to 6 mile to the gallon and they are getting :) :) 1 to 2 mile just be happy and fish

I have a 93 pro 17. just removed a 40 yamaha and hung a 70 on it. the 40 did 33 mph's , boat loaded , the 70 monday night did 41 mph's on gps turning 6000 rpm's. Sent the prop out to increase the cup and bring it down to 5,800. could have gotten more out of it but starts to porpose bad when trimmed up. going to take the hydro foil off my 40 and that should cure it. I think its good for 43 to 45 when done.

Mark

I don't have the manual yet. I'll have to get it soon.

Marinetech

That's the performance range I was hoping for. If you don't mind, what prop diameter/pitch are you running on your 70 horse?

I know that without a working tach any changes to the prop is just uneducated guesswork.

its a yamaha prop and the numbers are gone. it measures 13 1/2" in dia. I will have to call H + H prop. and ask them what it is. I just had them put a heavier cup in it. that knocked my rpm's down to 5,800 which is great but lost 2 mph's. going to go with a new prop , same style but 1 more inch of pitch. will let you know what my pitch is now and what I end up with. I know if I can get it to stop slapping with the right prop it will do 44 to 45 mph's

Thank you, I appreciate it.

Just fish a let it alone and smile as you go past them fast boats you are getting 5 to 6 mile to the gallon and they are getting :) :) 1 to 2 mile just be happy and fish

I agree with this totally. And I think your boat is on par for for where it should be . I used to have an '05 tracker pro guide v16 with a 60 merc on it and it did low to mid 30's with two people in it. Just remember you cant catch any fish when youre goin that fast anyways so it doesnt make much of a difference.

nothing wrong with getting everything possible out of your boat. checked my prop and it is a 13 1/4" x 17" pitch with a heavy cup added. just picked up a 13 x 19 to try. I think it might be a little to much pitch but will find out this weekend. will let yo know what it does. have plenty more to try.

That's great, I appreciate the information.

Hey goldstar  I put a 13 1/4" x 19" pitch turning point vented prop on and a SE sport 200 hydrofoil on my 70 today. won't have a chance to try it til sunday , the boatyard is nuts , way to much work. I will let you know the results sunday night.