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View Full Version : predator backfiring at topend!!



snakeman52646
08-29-2007, 08:13 PM
Ok I am a 2 stroke person , But I picked up a predator and love it. Need some help on it thou. It is fine from closed to 3/4 throttle you get above that and it back fires and shoots a flame out the pipe. it runds good up until 3/4 throttle. but open where it cuts out and sputters. It is stock. Also I have noticed if I do not turn the gas off on it when I am done riding it will leak out the over flow and leave a puddle.
thanks,
Billie

LT250_JOE
08-30-2007, 05:43 AM
I'M NOT AN EXPERT, BUT THE PUDDLE ON THE FLOOR IS FROM YOUR FLOAT STICKING IN THE UP POSITION ALLOWING FUEL TO CONSTANTLY FILL THE BOWL WHETHER NEEDED OR NOT. I'M NOT SURE IF THAT WILL CAUSE A WIDE OPEN THROTTLE RICH CONDITION. THE POP/FLAME IS UNBURNED FUEL IN THE EXHAUST SUDDENLY IGNITING. CARB HAS TO COME OFF EITHER WAY SO TAKE IT APART AND SEE WHAT YOU HAVE(JETTING, ETC)

snakeman52646
08-30-2007, 03:45 PM
ok pulled the plug and it was black, not wet just black that was after only 20 mins of riding. Got the overflow prob fixed where it does not leak out the overflow no more. It's got a 150 main,2.5 starter,and a 45 pilot. The clip is a 6cgy7-60 on the 3rd clip from top. I belive thats all correct. I have highered the clip to the 2nd and top mark on the needle which in turn would lower it to lean it out. This did nothing still back fire and pop at 3/4 to full. Change the oil and filter because I heard if gas gets down in your motor from the carb overflowing can cause it to backfire. Not sure if true but did it and still the same. Tightened my exhaust header up just to be sure cause heard that can do it. no change. Could it actually need a smaller main than a 150? Whats stock? I have a banshee and a 250r and can work on them with my eyes closed! But this four stroke has my head a spinning!LOL. Any help would be very appreciated.
Billie

snakeman52646
08-30-2007, 04:24 PM
Ok took the air duct off so would get more air to lean it out to see how it ran. well i didn't everytime went to give it gas just died. Ok and to explain hopefully better what it's doing. you get on it to ride and take off. You can hold it wide open and it will run right up to a certain point then it will stutter and back fire. In other words if I take it down the road and quick shift thru the gears it will accelerate just fine but once it gets to that point of high rpms( 3/4 to open) it does its thing. Also it seemed to be running ok, then on Tues put gas in it and it seem to start acting up. But put the same gas in my van from the same station at same time and it seems to be running fine?
thanks,
Billie

bossman525
08-30-2007, 07:09 PM
i had a 04 pred about 3 years ago and stock set up i believe it had a 148 main. try lowering your main and see what it does.

snakeman52646
08-30-2007, 08:13 PM
thanks will give that a try. Did change gas and no effect still has prob.
thanks,
Billie

honda450rider33
08-30-2007, 08:28 PM
from 3/4 to top is the main jet i would check that(go down a size)