Lowe 1448 w/Evinrude 50/35 jet

[fatherfire89]

Here is my build. Not quite finished but almost. Below is a short video when I was out on the Yellowstone in eastern MT (about 6 or 7 miles upstream of the diversion dam in Forsyth, for those of you who are from around here)

https://www.youtube.com/watch?v=6RiJCBXSCuU

 

[hotshotinn]

nice setup you have there.how fast you getting out of it?i has a 1448 but only a 20 jet on mine #-o

 

[bulldog]

Cool boat you have there!!

 

[fatherfire89]

I haven't had it out with a GPS yet but my best guess is 25 mph. I really wish I could get an impeller with a higher pitch to add some speed.

 

[Lil' Blue Rude]

I haven't had it out with a GPS yet but my best guess is 25 mph. I really wish I could get an impeller with a higher pitch to add some speed.

What rpm you turniing? Have you bought a stainless for it.
There's lots of potential for that motor. I've got the same motor on a 16' 42" and I'm running in the low 40's. A 6 1/8 stainless 3 blade will pick up plenty of water, no need for a change in pitch.

 

[fatherfire89]

My tach is showing 5200 rpms at full throttle (6 pulse, 12 pole is what i have the switch on). I have the stock aluminum 3 blade impeller right now. 40 mph would be simply awesome. you think I should get a four blade stainless impeller?

 

[Lil' Blue Rude]

DO NOT get a stainless 4 blade for yours. Your not turning enough rpms to really need a 3 blade stainless but a 4 blade would kill yours. I just tried one in mine a week or 2 ago and I couldn't tell much of a diffrence in hole shot but I lost at least 4-5mph off my top end. I'm turning around 5800-6000rpm.
You've already got the big carbs so the next easy hp is shaving the head a little. Take around .035" off and that will give you some low end grunt. Reeds help a little. Take the casting flaws out of the pump and make sure the impeller is sharp. bevel the leading edge of the liner so impeller blades almost touch the leading edge. Prettysure your motor should be turing more rpms then that. I've seen stock 40hps that turn around 5500rpm.
If you want some more top end move your gas tank farther back. Adjust the height and the trim of the motor.

 

[fender66]

Looks like a great little set up. Nice looking fish too. I've had some great outings this year, but nothing like that.

 

[fatherfire89]

5800 to 6000 rpms would be nice. Is your tach on the 12 pole/6 pulse setting? Maybe mine should be somewhere else. I'll have to look into doing some of that other stuff. Looks like the guy that owned the motor before me took a grinder to the inside of the impeller liner to try to smooth out the ridges so replacing that is the next step. You think cleaning the carbs might help increase RPMs? I dont know the condition of them and dont know the last time they were cleaned.

 

[user 6672]

Aslong as you can shim it to spec you dont need a new liner, run it until your ready to buy an impeller also.

As for the carb's.. if it aint broke dont fix it. If they arent leaking gas or acting up to the point you cant fix it by running it richer or leaner dont mess with them.

Good looking rig also..

This is all my opinion, take my advice as you will.

 

[Lil' Blue Rude]

Don't really know about the tach thing.Don't have a tach. I've just drove enough boats that turn 5700rpm or so that I can tell mine turns more rpms then that by the sound. Not scientific but the way I figured when I was hot rodding the motor if I can't tell it by the seat of my pants it didn't help me. I've got a screaming little motor to show for it. If the liners got alot of bad grooves it may help to replace it but if they're not too deep you won't see any diffrence unless it's not shimmed right. You might get a compression tester and check the compression. Should be around 135-140psi.

 

[fatherfire89]

Any idea how fast this stock motor should push my boat assuming it's set to the right height, shimmed perfect, and turning max RPMs? Everything seems to be set right but I'm not getting as much top end speed as I was expecting. Then again I dont have power trim/tilt so I haven't been able to mess around with height and angle.

 

[moark]

I have a 50/30 four stroke Merc and I turn ~5500 rpms at ~30 mph with gps. It's on a 16' Bass Tracker so I'm probably heavier than you but my guess is you're normal for a stock 50/30.

 

[Lil' Blue Rude]

Tilt and trim makes a big difffrence in how it comes out of the water and how fast it can be on top. Your gas tank being in the front is good for keeping the boat flat in the water but it slows you down bad on top end you should gain a couple mph from moving it behind your console. No one runs their gas tanks that far up around here. We always have them behind bench between the transom. I think your boat/motor is capable of the low 30's.
You want your motor just as high as you can get it without it cavitating out of the hole.

 

[fatherfire89]

OK thanks guys. So next time im out I'm going to play around with moving the tank back and swapping out the impeller liner. I originally mounted the tank up front so the boat floats in more shallow water for float fishing but now I just want more speed haha. Next time I'm out I'll do a before and after speed check with a GPS and let you guys know the difference.

 

[fatherfire89]

Ok so I took my boat out this evening and unfortunately I ran out of daylight so I didnt have time to mess around with moving the gas tank around. I did, however, bring a GPS and I was running 23.5 MPH upstream and 33.2 downstream in the same channel. That was with 4 gallons of gas in the tank up front. Next time i'm out I'll swap the liner and move the tank around.