[tunr4life]

i was wondering if u guys can help me i have 04 v force and when i rev it it backfires like crazy i mean loud pops i changed the spark plugs and messed with the air fuel mixture i running out of things to check right now the quad has t4 exhaust would that make it back fire or should i check my valves? hope u guys can help

 

[aaron_j]

may be running too rich, or something with the carbs. valves would be the bikes hard to start.

 

[tunr4life]

backfiring

the quad starts right up the guy who had it bfore me put the t4 on and left one stock header pipe and the other is a performance pipe

 

[aaron_j]

hmm, i know my bike was doing it, still is bc its running rich. you should do the carb mods as well. clip 2 coils off the spring on the needle, and polish the slides and shim the needle with a #4 washer!

 

[RobCatV]

Check for exhaust leaks.

 

[starroneup]

I'd be checking Carbs and Jetting first.

 

[VFORCEJOHN]

exhaust leak.

too LEAN. lean causes pops on these motors

incorrect jetting for exhaust/airbox mods.

dirt in carb

JOhn

 

[JRENIGAR]

^^^ agreed. Lean causes backfires especially when decelerating.

 

[Kenny4]

Your running the stock front head pipe---So check how the fit is going into the T4 can----Also when first starting run your hands all around the header pipes to feel for leaks, (careful as they can heat quickly)---Also take a 2'-3' piece of small tubing and put one end in your ear and with the other go all over the pipes---If you hear the exhaust noise increase, then you have found a lead.

Kenny

 

[tunr4life]

backfiring

thanks for the quick replies everyone gonna try all the suggestions and post the results thanks

 

[bansheemaniac]

My vforce runs like crap too. i think im having the same issue, at idle it seems to miss, and it misses all the time. less if i put the choke on all the way.

Could it be the exhaust? ive checked all electronics, even sprayed out carbs multiple times and all is good.



Any help would be good.

Thanx,
Lance

 

[tunr4life]

backfiring

i fixed the problem i cleaned the carbs and adjusted the air/fuel mixture and that took care of the problem

 

[hkunz]

I've had the same problem, the intake valve on the rear cylinder was slightly too tight, and the jets needed to be opened up. Still haven't put the washers on the needles, that's this weekend. Popping is getting better.

 

[bansheemaniac]

ya but mine doesn't neccesarilly pop, it misses alot and wont idle, the valves were checked less then 20 hours prior to this happening, but it would be hard to start if it were the valves right? because it starts like a charm


Thanx guys for any info that you can give me, as i want to get out and ride asap

Thanx,
Lance

 

[hkunz]

Turn the mixture screws out 1/4 turn, see if that helps. If so, then look at changing jetting, if not, put it back and keep looking. My valves were a tiny bit too tight on the back intake which caused a lot of backfiring. The backfiring caused the front carb to pop off the intake boot, changing the symptoms while I was troubleshooting. Very frustrating. Jusr keep at it, and only change one thing at a time.