dale1983

Whats up guys, I have a ATV turbo project Im working on, the turbo is a t3/t4 hybrid I got from ebay, now for my issues and progress.

Progress: everything is mounted and working.

Issues: I am having a hard time getting it dialed in, it starts fine runs good, but after 1/2throttle it just pops and backfires and sometimes stalls.

What I got: 2001 400ex atv, t3/t4 turbo, mounted with oil lines, charge pipe is straight from turbo to carb "for now", carb vents have been pressurized with turbo. no intercooler, no air plennum yet.

I built a air plennum/ charge box whatever you wanna call it, havent installed yet?

My plug is still white and shows possible slight detonation, even with heavy jetting, could this be causing my backfire/poping?

Will a air plennum help the palpitations in the air and possibly solve the problem? or should I need to retard the timing a bit? or both?

Im very very new at turbos and dont know a whole lot if anything...lol.

It deffinetly is getting more power and working up to the 1/2 throttle point, then falls flat on its face.

What could be going wrong? I need some expert advice and this site has alot of good stuff, but im still stuck at the moment.

Any help is greatly appreciated, thanks for your time.

SlowSL

I'm in no way experienced w/ ATVs, but from my experience w/ cars, I've experienced white plugs shorty before engine failure running lean. I've also had some settings wrong in my tuning software and had it go VEEEERY lean at WOT and the car falls on its face, and kind of popped/backfired a bit. I would find a way to dump more fuel and see what happens. Might not be a bad idea to run race gas to give you a little more cushion in case you are running lean/pre-detonating.

honeydanny84

i have no such kind of experience