I've been getting quite a few PM's asking about the performance of my new 300 Pro XS 4.6L V8.
Thought I'd take a few mintutes to update my progress so far with my new motor setup and performance.
I wasn't sure which section to post in, so since I've got a Triton, I put it here.
I apologize in advance for this being a little long winded. I did pare it down quite a bit.
I did the initial 2 hour break in last Sunday, following break in procedure to the letter. When it
came time to go WOT, I could only spin motor to 5000 rpm (56 mph). I just assumed that I was overpropped
with the 26p Fury 3 blade off my old motor.
Even though I no top end, hole shot was incredible. I was up on plane in 3 to 3.5 seconds.
I always start with jackplate all the way up and motor tucked in. I could really feel the increase intorque from my 2 stoke.
The motor had strong acceleration all the way to 5000 rpm.
(found out the next day my throttle wasn't calibrated and only had 80% power)
Went back out Tuesday to put some more time on the motor and test some props.
I started with a stock 25p Tempest Plus with 3 large plugs.
Hole shot was the same (3 to 3.5 seconds to get on plane).
Spun it up to 6000 rpm and hit 74 with little effort. I didn't push it past this point as I was just past
the 2 hour portion of the break in.
I did notice that the boat had a completely differant feel than with the 2 stroke. Seemed to be a little
more squirrely and took more effort controlling the chine walk. Previously the boat had very little bow
lift and drove very flat like some Rangers I've been in. Had plenty of bow lift now, not sure if its
because of motor or the addition of 2 degree wedges or a combination of both.
I swapped out the prop back to my old 26p Fury 3 blade and the motor still had excellent hole shot and acceleration.
I got to 6000 RPM and 75 mph and suddenly there was a god awful loud rattling noise coming from the engine.
Scared the crap out of me as I assumed the worse and thought I had blown my new motor to bits.
I backed off the throttle and the noise disappeared.
I checked the motor and everything seemed fine. I accelerated again whle my buddy watched the motor.
Hit 6000 rpm and 75 mph and the rattling came back. Turned out that my port power pole was catching spray
and the spike was pulling away and slapping back into place. This never happened with my 2 stroke.
Anyway, so far I am very pleased with the performance of the new motor. It pulls alot harder than my 2 stroke
and gets the boat up to speed alot faster. The motor sounds pretty cool at start up. It has a very throaty growl
to it. My buddy compared it to a small block chevy on a muscle car.
Mercury Tech told my that once the motor loosens up, I should gain another 150 or so RPM's, so I think I'm close
with either prop. As I said before, the boat feels and acts completely differant so I'm going to have to
play with trim and jackplate to get my best setup (and raise my power poles). I am optimistic that I will
get close to breaking the 80 mph mark once I get the setup right.
2016 Triton 21TRX dual console
2018 Mercury 300 Pro XS 4.6L 4 stroke
2 power pole blades
45" 36 volt Ultrex
10" Bob's hydraulic jackplate
2 degree positive wedges
4 AGM batteries
Dual 9" Lowrance GEN 3's at console
12" Lowrance GEN 3 at bow
Vessel View Link displayed to Lowrance
Windy with a slight chop
Water temp 71.9 f
water pressure 4 psi at idle
water pressure pegged at 30 psi WOT
3" p2p
26p Fury 3 blade (b&b'd with some cup added)
6000 rpm @ 75 mph
2 people (350 pounds)
3/4 tank of fuel
med load
I will update stats once I get my setup fine tuned.