1998 ZR500 Bogging and Backfiring issue - Snowmobile Forum: Your #1 Snowmobile Forum

donstone92784 · 12-26-2012, 07:57 PM

I got a 1998 zr 500 this year. Got it to run and idle fine. Just took it for its first ride and it bogs intermittently and backfires sometimes afterward. After it takes off it goes good but when I let off the throttle to make a turn and try to start again it will fall on its face but then take off again after feather the throttle. I checked for spark, both plugs looked good and had blue spark. I pulled off the kill switch plug and that didn't solve it. The ground going from the speedometer to by the handlebars is off, it looked like the prior owner flipped open the hood too fast and broke the ground wire. I saw in some of the forums that grounding could be part of the issue, but I wasnt sure if that was the only ground. I am new to snowmobiles and would greatly appreciate any help.

**kccats** · 12-27-2012, 05:55 AM

To start with did you clean the carbs real well? And the clutches? Is the belt running atleast an eighth out of the secondary? Is your center to center 12.2?

donstone92784 · 12-27-2012, 07:56 PM

I cleaned the carbs really good. Took them out twice and cleanrd them. I fixed the ground wire and it seemed to idle a little nicer. I can hear it sputter a little bit when it idles. Its still bogging down and backfiring some. I dont know about the clutches. How do i check or clean them? Im pretty new to snowmobiles, so i definitely have a lot to learn.

**kccats** · 12-27-2012, 09:44 PM

OK did you floss the pilot jet (up in the tube)? Scotch Bright(green pad for dishes) the clutch serfaces and blow them out real good! Next thing to check would be the reeds! The 6 bolt flanges in front of the carbs! Hold them up to a light and see if there is any light? If so take them apart and flip them over?

Blaine1 · 12-28-2012, 07:30 AM

Kind of sounds like the TSS/Kill switch issue but you said it has already been unplugged so that is bypassed. Could be a lot of things...ohm out the stator just for peace of mind.