problem with 2008 800 dragon

[dieselsmoker]

i was wondering if anyone could help me with diagnosing my problem. i own a 2008 dragon 800 with only 1750 miles on it. i was riding it this weekend in the mountains, on the second day of riding 6 or 7 times i would either switch it from reverse to drive or vise versa it would die and i would have to restart it. also for a while it was running real ruff. we also pulled the plugs and one had oil on it and one was clean. the people i was riding with said it must have been running on one cylinder. but it never seemed to lose any power. if i got on the gas it would run like a champ and pick up and go. also the day we where leaving i started it up and it ran for a few minutes then died. after i restarted it it ran ruff untill it warmed up and it seem to hav all the power, then when i got home with the sled to unload it seem to just run fine.
the top end in my sled was replace 600 miles ago and the whole engine replaced 1000 miles ago. the sled has had all the updates. i bought the sled used and it is my first sled if anyone could help with this that would be great cause i plan on doing all the work myself to fix it. also one guy on the trail was tell me it could be as simple as the throttle postion sensor in the throttle.

 

[fnDan]

Could be the TPS. My 900 is running close to the same way. Dies when I try reverse and idling too low. Once in a while it idles fine.
I made a TPS tester but I didn't read all of the instructions and forgot to test the TPS with the idle screw back all the way out. Once it warms up a bit I will set mine again.

I've heard there could be moisture in the TPS connector too so I will be putting dielectric grease in there.

 

[Rene G]

Check your reeds, I had Vforce's and the got all messed up and the sled ran great on the throttle, but would spit, sputter and spurt at half throttle and below.

 

[retiredpop]

I don't know if this is applicable to your sled or not but for what it's worth here is some info from another site...

Altitude Setting
If your engine is carbureted, you can adjust the elevation setting
of the Polaris electric reverse control (PERC). If your engine is
a Cleanfire system, this is automatically done through the
engine controller unit (ECU), and you do not need to do any
setting.
At higher elevations over 6000 ft (1829m), the engine requires
a different ignition RPM setting to improve the operation of the
reverse system.
To set the altitude settings:
1. With the engine running, push and hold the reverse button
for 5 - 6 seconds and then release the button.
2. The reverse light will flash rapidly on the instrument panel.
3. You have now set the PERC system to the higher elevation
setting.
4. To go back to the low elevation setting repeat step 1. The
reverse light will flash slowly indicating that the system is
now in the lower elevation setting.
NOTE: The elevation setting will be set in the
memory (engine running or not) until it is changed.
Important Notes
• Max RPM for shifting into reverse = 4000 RPM
• Max RPM for operating in reverse = 6000 RPM
• Engine must first reach 900 RPM at start up before the
reverse system can be used. The system works between
900 and 4000 RPM.
• If the button is pushed above 4000 RPM the system is
bypassed and nothing will happen.
• Flashing light on the instrument panel indicates that the
system is in reverse. On carbureted units a slow flash
indicates that the system is set for low elevation, and a
fast flash indicates the system is set up for high
elevation. Push and hold the reverse button for longer
than 5 seconds to toggle back and forth from high and
low elevation settings. On Cleanfire units this is
automatically done through the engine controller unit
(ECU).
• Elevation above 6000 ft (1829m) requires a different
timing curve to eliminate a “kick-back” effect.
• If engine is shut off or dies in forward or reverse gear,
the engine when started will automatically be in
forward gear.

 

[looneyrod27]

have you check your belt deflection?{belt tightness} if your belt is too tight it will make your machine idle too low to engage into reverse. should have an 1.25" slack

 

[dieselsmoker]

thanks for all ur help guys could it maybe be the coil my buddy was saying at low rmp just at ideal it wont produce spark untill it gets up and goes