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Xc Sp 700 Backfiring Problems

L
Aug 21, 2017
14
0
1
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Hey Guys,

My 99 Polaris Xc Sp 700 has a backfiring problem. I have cleaned the carbs and I have also replaced the reeds because they were bad and I read that bad reeds could contributed to a backfiring problem. The new reeds helped a little but it still backfires when idling and at take off. What could it be?

Thanks
 
M

minus40

Well-known member
Oct 22, 2001
213
96
28
If it's popping in the carbs it's lean. Up the pilot or adjust the fuel screw. Keihin carbs are notorious for this. I used to adjust damn near daily. A neat trick was to use a welding rod, clean off the flux and hammer a flat end in it for a long screwdriver and store in the hood foam
 
L
Aug 21, 2017
14
0
1
30
I just set the fuel/air screw to 1.5 turns today and that helped a lot. I have an exhaust leak so when I fix that, hopefully tomorrow, the backfiring should stop. Thanks for your feedback.
 
L
Aug 21, 2017
14
0
1
30
Hey guys,

I am still having the same problem with my sled, I can't figure it out. I fixed the exhaust leak and I have done everything I can think of and it still backfires. Can anyone think of something.

Thanks
 

retiredpop

Well-known member
Lifetime Membership
Jul 3, 2001
1,349
295
83
Calgary
Turn the idle mixture screws in until it idles without backfiring and has good throttle response. Turning them in richens the mixture as they are air screws. I believe we ran ours about 1 turn. If you get to less than 1/2 turn then you need bigger pilot jets.
 
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