Recently I installed a HMF optimizer, and HMF XL exhaust on my 07 Honda Rancher 420. I have been trying to fine tune it, but when the engine is cold (and temp outside was about 40) it started and died about 5 seconds later. During that time I noticed that the headlights flashed off and on. After the engine died the engine would not restart. It would turn over, but not start. I checked the spark and it had plenty of spark. The bike is about three years old and I have not changed the battery yet, so thats where I started. After new battery, same problem. I noticed that the spark plug was BLACK and WET (with fuel). I put a new plug in it and it started right up. Running fine. (still fine tuning HMF optimizer though).
SO, on to next problem.......I attempted to turn the headlights back on but they would not come on. I checked the fuses in the rear fuse panel. All are fine. Even swapped fuse to see, and still nothing. I looked at the bulb, and the elements look fine but I will be changing them hoping it caused an electrical spike that burned out the elements.
So....If yall have any recommendations on what to look at next please let me know.

 

Found problem...It was the headlight switch on the handle bar. IT was bad... New assembly $80... not bad... but have to take the whole wiring harness out.

 

t’s hard to improve something that doesn’t need improvement. That was Honda’s basic struggle as they released the new and improved Rancher 420 ES for 2007. There is no question that Honda had a good thing going with the Rancher 350; it provided years of tremendous sales and popularity. With 500,000 units sold since 1996, one would question if messing with a good thing would be bad. However, Honda timed it just right with appropriate and needed upgrades to continue to make the Rancher ATV one of the best-selling ATVs on the market today.

 

Oh so did you solve the problem or is it still there.Do tell us.

 

Oh!, is the problem is solved or still exists.