Join Date: Apr 2019
Location: Candle Lake Saskatchewan Canada
New to this forum. Own a 2002 Quadrunner 500 and 2007 King Quad 700.
Started having serious issue with the KQ700 this weekend. Started up OK, seems to work fine when cold, but after warmed up it starts to backfire and run REALLY ROUGH. If I feather the throttle and can get the rpm's up it will mostly pull itself. On one trip this weekend I did this throttle feathering for about a mile while it backfired and ran rough, then I turned a corner and then it worked perfectly normal for the next mile (I didn't do anything different--just like someone threw a switch, i.e., quad running poorly then all of a sudden it was fine). Battery was run down, charged the battery overnight and it seemed to work OK for the first 30 minutes the next day (cold) and then started acting up again once it was warmed up. Battery still has enough of a charge to start the quad.
- quad had worked well since new in 2007. I did have the battery drain issue that I put in a switch to isolate the battery when not in use.
- Fall 2018 I winterized, changed oil, added fuel stabilizer, new spark plug (~3000 miles)
- quad sat over winter (~6 months), added 3-4 gallons fresh fuel this spring and first trip of 10-15 miles it worked as normal
- this weekend once the quad was warmed up it started backfiring, running really rough.
Google searches suggest a plugged fuel filter--I can try this, but highly doubt the fuel filter is the issue as it seems to work OK when cold, just when it is warmed up that the issue surfaces and even at that it will choke and sputter for a while and then all of a sudden start working normal (if it was a plugged fuel filter it the problem should persist).
- I will try changing the spark plug (even though it is a new plug these things can be faulty from factory)
Seems more like an electrical problem. I am not sure what shape the battery is in, but it does take a charge OK, and it has enough of a charge to start the quad.