Suzuki 750 Kingquad AFi stalls on take off

[po_hara]

Hi, sorry I'm new to this so not sure if I'm doing it right!

I'm from Ireland, recently bought a 2009 Suzuki 750 Kingquad AFi and having a small issue (at least I hope it's a small issue!!)

When I start the quad, it fires up, revs etc all as it should, but when I put it into gear and give the throttle a jag it stalls, if I give it the throttle very gentle, it revs up but does back fire slightly and moves off fine!

The battery was bad in the quad and I changed that, thinking that the pump wasn't getting enough power for injection and I also replaced the spark plug and cleaned out the main fuel lines. It's definitely better than it was, but does still cut out at times! Once the rev gets up and I'm moving on, it runs like a dream.....flying machine! If I come along the road or fields, and slack off the accelerator to about quarter then throttle on, the quad picks up and away like it should, but when I go back to idle / low rev, I have to give it a lot of throttle to keep going, if I go for a small rev to maybe turn around or run up to a gate, it has a habit of stalling or back firing abit!

Is there anyone who could suggest anything I should do / have missed, etc?