2008 Brute Force Popping and Sputtering
I need some guidance for an issue with my Brute. I've read multiple threads and tried a handful of different things with no success.
2008 Brute Force 750
4372 kms (2716 miles)
MSD purchased from VForce John tuned for 2" snorkels & stock exhaust
Catch can mod
About 5 months ago the Brute began to pop and sputter from a cold start when starting to ride but it typically goes away after a few minutes, it rarely does this from a cold start. After letting the Brute sit for 20 min It'll start / idle fine but will sputter & pop way worse when I try to ride it. Idle good, 1/3 to 1/2 throttle extreme popping and sputtering, full throttle it'll pop & sputter then take off. When it's popping and sputtering I can hear it from the air box too, it seems to be starved of fuel. This doesn't go away until the Brute sits for extended periods or overnight which tells me it could be related to heat.
What have I tried:
- Fresh gas
- Gas tank checkvalve good, not starving it that way
- Highly suspicious of the fuel pump being an 08 Brute
- Had pump tested at dealership and its pumping 42psi
- Pump screen was dirty and they cleaned it, I thought this was the magic bullet but no
- Throttle positioning sensor checked also by dealer
- I removed MSD and ran stock, problem still exists
- Checked wiring under the seat and fuses
What I suspect:
I suspect the fuel pump could be the culprit seeing how the problem surfaces after the machine reaches running temperatures. The dealer probably ran it for short tests not allowing it to reach operating temperatures. It's still the original fuel pump too. 08s are notorious for having fuel pump issues but I don't want to change it if it could be something else. I'd like to explore all my options before I take the plunge and pay for an overpriced fuel pump.
I love this machine but honestly I feel like pushing it off of a cliff
2008 Brute Force 750i
26" ITP Mud Lite XL
2500lb Warn Winch
VFJ MSD Charge FI
Catch Can Mod
Last edited by DanOMite; 09-03-2018 at 06:25 PM.