My 96 425 Magnum has a miss and backfires out of the exhaust.It will run but doesnt have the crisp sound it should sounds is real dull.Acts like the timing is off.There is no rattle from the head area so I dont think the cam is bad(hope not).What i need to know is can the cam chain stretch or let the timing move.Or what else could cause this?Thanks for any iput

 

check your basics first how is your air filter. dose your aaen silencer need cleaned or repacking or dose that not apply.i think backfires are usually result of a rich condition and if filter or silencer are plugged it might cause this.since you said you pipe dosent sound as crisp try checking that first.have you rejetted since you put these parts on you didnt say? if these are ok then check your timing. if still no luck check all your grounds this can in some rare cases cause a missfire.

 

My machine was acting up in the same way. It would backfire, seem to loose power and eventually die out. It turned out that a spring inside of the carb,(diaphram spring) had fallen out of place. This caused the carb to run rich at times because the fuel supply wasnt being regulated. Just dumped in the carb and the motor couldnt always keep up. The dealer said he never saw this happen before. It may be worth checking. The spring is in the upper carb, its suppose to be positioned "up and down", mine was just laying sideways. Hope this helps.

 

All that was wrong was the exhaust valves were to tight.Adjusted the valves and it runs like new.