# Dirt Bike guys step in, carburetor guys too... Backfire/startup issue (also stalling) **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [March 29, 2014, 9:19pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814 "2014-03-29T21:19:02Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![donkeyballs69](https://avatars.discourse-cdn.com/v4/letter/d/f6c823/32.png) [@donkeyballs69](https://forums.speedlife.net/u/donkeyballs69)\ **Post date:** [March 30, 2014, 6:32pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/21 "2014-03-30T18:32:21Z")
Your pilot jet really only controls idle and when you first get on the throttle. So your main jet and needle are fine from pics of the plug and you don’t notice it any other time. ---
**Author:** ![Willybeen](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/willybeen/32/7351_2.png) [@Willybeen](https://forums.speedlife.net/u/Willybeen)\ **Post date:** [March 30, 2014, 6:33pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/22 "2014-03-30T18:33:23Z")
Are you saying you still think it’s carb or timing? Sent from my SPH-L710 using Tapatalk ---
**Author:** ![Willybeen](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/willybeen/32/7351_2.png) [@Willybeen](https://forums.speedlife.net/u/Willybeen)\ **Post date:** [March 30, 2014, 6:34pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/23 "2014-03-30T18:34:47Z")
I’ll be honest, this bike has been ridden hard since the day I bought it. Stoppies, wheelies, and high revs every time I ride it. Always warmed up and oil changed every 600 miles or so. Sent from my SPH-L710 using Tapatalk ---
**Author:** ![donkeyballs69](https://avatars.discourse-cdn.com/v4/letter/d/f6c823/32.png) [@donkeyballs69](https://forums.speedlife.net/u/donkeyballs69)\ **Post date:** [March 30, 2014, 6:47pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/24 "2014-03-30T18:47:05Z")
I still think it’s the pilot jet. I would try the fuel screw first just to see if it helps. ---
**Author:** ![Willybeen](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/willybeen/32/7351_2.png) [@Willybeen](https://forums.speedlife.net/u/Willybeen)\ **Post date:** [March 30, 2014, 6:48pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/25 "2014-03-30T18:48:49Z")
Will do. Tomorrow am… Any other ideas are appreciated… Sent from my SPH-L710 using Tapatalk ---
**Author:** ![donkeyballs69](https://avatars.discourse-cdn.com/v4/letter/d/f6c823/32.png) [@donkeyballs69](https://forums.speedlife.net/u/donkeyballs69)\ **Post date:** [March 30, 2014, 7:11pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/26 "2014-03-30T19:11:30Z")
I would check the valves second, expecially since you ride it hard. I know drz’s are bullet proof but yours is modified pretty good. These are just my opinions from my experience and what I would check first. Hope it helps, but I could be wrong. Haha. ---
**Author:** ![Willybeen](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/willybeen/32/7351_2.png) [@Willybeen](https://forums.speedlife.net/u/Willybeen)\ **Post date:** [March 30, 2014, 7:24pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/27 "2014-03-30T19:24:54Z")
:tup: Sent from my SPH-L710 using Tapatalk ---
**Author:** ![Vandal171](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/vandal171/32/6259_2.png) [@Vandal171](https://forums.speedlife.net/u/Vandal171)\ **Post date:** [March 31, 2014, 4:47am UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/28 "2014-03-31T04:47:29Z")
I agree with the pilot jet being partially plugged. If you don’t want to pull the carb you can try adding half a cup of Seafoam to the fuel on your next fill up. I have had very good luck with this carb cleaner. ---
**Author:** ![KuntryQuestTSi](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/kuntryquesttsi/32/5010_2.png) [@KuntryQuestTSi](https://forums.speedlife.net/u/KuntryQuestTSi)\ **Post date:** [March 31, 2014, 6:19am UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/29 "2014-03-31T06:19:13Z")
You might be able to cheat on the carb. Rather than fully removing it. Loosen the clamps and turn the bottom one way or the other. I honestly don’t Remember if there is room to do this or not. I did it on the ktm trying to dial the jetting in. Sent from my XT907 using Tapatalk ---
**Author:** ![jay\_g](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jay_g/32/111288_2.png) [@jay\_g](https://forums.speedlife.net/u/jay_g)\ **Post date:** [March 31, 2014, 6:33am UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/30 "2014-03-31T06:33:15Z")
As said check pilot and valves. Tight intake valves will cause hard starting and can backfire when the cylinders fill with fuel from cranking it. Based on the plugs the needle and main jet look pretty good. Popping on decel again points to pilot. ---
**Author:** ![donkeyballs69](https://avatars.discourse-cdn.com/v4/letter/d/f6c823/32.png) [@donkeyballs69](https://forums.speedlife.net/u/donkeyballs69)\ **Post date:** [March 31, 2014, 7:21am UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/31 "2014-03-31T07:21:11Z")
[quote=“KuntryQuestTSi,post:29,topic:268814"”] You might be able to cheat on the carb. Rather than fully removing it. Loosen the clamps and turn the bottom one way or the other. I honestly don’t Remember if there is room to do this or not. I did it on the ktm trying to dial the jetting in. Sent from my XT907 using Tapatalk [/quote] That’s how I normally do it, but like you said I have no idea how that bike is setup. It’s an old design so I’m sure it would work. - - - Updated - - - [quote=“jay\_g,post:30,topic:268814"”] As said check pilot and valves. Tight intake valves will cause hard starting and can backfire when the cylinders fill with fuel from cranking it. Based on the plugs the needle and main jet look pretty good. Popping on decel again points to pilot. [/quote] Also he said when he cracks the throttle open it starts. That’s why I’m going with the pilot and 2nd choice will be tight valves.:tup: ---
**Author:** ![Spam16v](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/spam16v/32/5287_2.png) [@Spam16v](https://forums.speedlife.net/u/Spam16v)\ **Post date:** [March 31, 2014, 8:38am UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/32 "2014-03-31T08:38:43Z")
> [@KuntryQuestTSi](#): > > You might be able to cheat on the carb. Rather than fully removing it. Loosen the clamps and turn the bottom one way or the other. I honestly don’t Remember if there is room to do this or not. I did it on the ktm trying to dial the jetting in. > > Sent from my XT907 using Tapatalk dick bag steel frame makes it hard on these ---
**Author:** ![Willybeen](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/willybeen/32/7351_2.png) [@Willybeen](https://forums.speedlife.net/u/Willybeen)\ **Post date:** [March 31, 2014, 2:08pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/33 "2014-03-31T14:08:08Z")
Did nothing to bike, cold started flawlessly. Added seafoam to tank, drove for 10 min, parked it, restarted flawlessly 10 min later, added more seafoam, rode around for an hour, refueled and drove home. Bike seemed to backfire less on completely closed throttle when at high rpm, so no complaints there. Actually felt great all day. I took it out again a few minutes ago, to get more gas, grab coffee, etc and each time I started it, it required me to twist the throttle to get it to fire. Another symptom I noticed is the starter sometimes seems to catch (feels almost like a dead battery for half a second) then she cranks normally. I did replace the stator and rectifier not long ago with an aftermarket unit that seems to throw 15ish volts… Not sure if that’s an issue or not, but figured I’d just mention it. I hate the long starts. (no backfires on startup today though) Sent from my SPH-L710 using Tapatalk ---
**Author:** ![Willybeen](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/willybeen/32/7351_2.png) [@Willybeen](https://forums.speedlife.net/u/Willybeen)\ **Post date:** [March 31, 2014, 2:09pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/34 "2014-03-31T14:09:00Z")
Stator and rectifier were done at same time 600 or so miles ago. Sent from my SPH-L710 using Tapatalk ---
**Author:** ![Vandal171](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/vandal171/32/6259_2.png) [@Vandal171](https://forums.speedlife.net/u/Vandal171)\ **Post date:** [March 31, 2014, 4:06pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/35 "2014-03-31T16:06:30Z")
Did these issues start around the time you changed the stator? Just wondering if it’s possible you got the ignition timing too far advanced. That would cause every one of these problems and she would go like hell too. ---
**Author:** ![Willybeen](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/willybeen/32/7351_2.png) [@Willybeen](https://forums.speedlife.net/u/Willybeen)\ **Post date:** [March 31, 2014, 4:22pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/36 "2014-03-31T16:22:24Z")
Yes… Not immediately, but I noticed them afterward. How is this remedied? Sent from my SPH-L710 using Tapatalk ---
**Author:** ![Willybeen](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/willybeen/32/7351_2.png) [@Willybeen](https://forums.speedlife.net/u/Willybeen)\ **Post date:** [March 31, 2014, 4:26pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/37 "2014-03-31T16:26:51Z")
What burns my as is this bike has almost every mod possible and my Buddy who owns the same bike with similar mods minus the big bore and cams (he has the thin head gasket, cams, 39mm carb, and exhaust) he’s damn near as quick as me and he’s geared for Highway use too… My bike should be raping him at 48 whp Sent from my SPH-L710 using Tapatalk ---
**Author:** ![Vandal171](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/vandal171/32/6259_2.png) [@Vandal171](https://forums.speedlife.net/u/Vandal171)\ **Post date:** [March 31, 2014, 5:43pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/38 "2014-03-31T17:43:09Z")
When you installed the new stator did you use locktite on all the bolts holding the stator and pick up coil to the stator cover? It’s possible that the pick up for the ignition has come loose and is vibrating around. ---
**Author:** ![donkeyballs69](https://avatars.discourse-cdn.com/v4/letter/d/f6c823/32.png) [@donkeyballs69](https://forums.speedlife.net/u/donkeyballs69)\ **Post date:** [March 31, 2014, 5:44pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/39 "2014-03-31T17:44:40Z")
Not if jetting is off. I would walk all my friends raptors with same parts but I spent the time tuning mine. Mine would power wheelie in 5, they had trouble in fourth. I won the grass drags they weren’t even in the top 5. You didn’t say anything about the stator before lol. Make sure that’s all good also. ---
**Author:** ![Willybeen](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/willybeen/32/7351_2.png) [@Willybeen](https://forums.speedlife.net/u/Willybeen)\ **Post date:** [March 31, 2014, 5:52pm UTC](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814/40 "2014-03-31T17:52:03Z")
I lock tighted everything when I installed th e stator… At least I’m pretty sure I did. I’m just giving you guys each symptom and each thing I’ve done to it. Sent from my SPH-L710 using Tapatalk [Previous page](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814.md?page=1) [Next page](https://forums.speedlife.net/t/dirt-bike-guys-step-in-carburetor-guys-too-backfire-startup-issue-also-stalling/268814.md?page=3)