hey i have a 2006 raptor 700 bored to 715 with 12.5:1 comp piston, stage 2 hotcams, valve springs, dynatech ignition, hmf full exhaust, dobtech fi controller, iridium spark plug, ect. and its backfiring like a BITCH.. almost always when i am in gear deaccelerating, so i assumed it is running rich, but it doesent seem to make a difference if i have it on the lean side or the rich side? gettin worried, the backfires are loud and annoying haha

 

Popping/backfiring generally means running lean. Are you running a racing fuel or some sort of racing blend with the high compression piston? You need to be.

 

you might want get a powercommader3 and take it to a good tuner and get a custom map, exp sence you have a very rare mod combo.

 

well its premium fuel with octane booster, why do you say its an odd combo for mods?

 

most people who go into the engine will have dual exhaust anda power commander. and like beefy said race fuel. i whould said 50/50 mix.

 

you should be running atleast 105 octane, depending on your elevation...

 

haha yea i bought my exhaust and fi controller first then did the motor mods, wish i had the money for duals haha, and yea its about 100 octane right now, i might be able to get some vp racing fuel but i dunno...

 

<div class="FTQUOTE"><begin quote>Originally posted by: 700R Ripper

hey i have a 2006 raptor 700 bored to 715 with 12.5:1 comp piston, stage 2 hotcams, valve springs, dynatech ignition, hmf full exhaust, dobtech fi controller, iridium spark plug, ect. and its backfiring like a BITCH.. almost always when i am in gear deaccelerating, so i assumed it is running rich, but it doesent seem to make a difference if i have it on the lean side or the rich side? gettin worried, the backfires are loud and annoying haha</end quote></div>

Backfire is a symptom of lean, and octane has nothing to do with rich and lean. If the power commander is set up right, (richen up the idle ), then its probably an exhaust leak. You might have to dope up the exhaust joints, and make sure they dont inject any air into the exhaust stream.

 

You aren't going to hit 100 octane with octane booster and premium. Even if that isn't causing this problem it will create problems in the future, so I would definately look into running at least a 50/50 mix of racing and premium.

 

i whould also highly recomend getting a pc3. if you sell yours it whould only cost maybe 100 more.