Full Version: Exhaust Backfire At Deceleration
Hey guys I have a 03 z400 today I was on a quad run and I noticed it slightly backfires at deceleration and down hills in a low gear. My quad performs great and is not overheating, it is cooling VERY well. Is it alright for it to back fire as long as its not overheating???
QUOTE (racer965 @ Sep 19 2009, 08:48 PM) 
Hey guys I have a 03 z400 today I was on a quad run and I noticed it slightly backfires at deceleration and down hills in a low gear. My quad performs great and is not overheating, it is cooling VERY well. Is it alright for it to back fire as long as its not overheating???
you might be too lean on your pilot jet.
QUOTE (trailrider19 @ Sep 19 2009, 05:38 PM)
you might be too lean on your pilot jet.
Yeah but thats not wat im asking. Is it alright to run my quad with the back fire????? my quad seems to perform fine and does not overheat.
QUOTE (racer965 @ Sep 19 2009, 09:53 PM)
Yeah but thats not wat im asking. Is it alright to run my quad with the back fire????? my quad seems to perform fine and does not overheat.
You have a small air leak in you exhaust system connections somewhere and no it won't hurt it, but the next time you have your exhaust off put some Permatex on the joints befgore slipping them back together...BUT let it drie 24 hrs before you run it...
http://doitbest.com/Exhaust+Clamps+Parts+R...-sku-579626.dib
Backfire on decell is cause by one thing... Oxygen in the exhaust system. It gets there one of two ways, either from an exhaust leak, or from being lean.
If your exhaust system doesnt leak, then you are lean at an idle for whatever reason. Your carb may be dirty, and the pilot or fuel screw, or idle circut passage may be partially plugged, or you may be jetted to lean on the pilot, or your fuel screw may simply need adjusted richer.
Is it ok to run like that? Yeah, it wont cause any major damage, but it can be hard on the exhaust system over time, and it also will make for an unstable idle, and can cause some poor throttle responce, and make it cold blooded if it is caused by a lean condition.
I would fix it if it was mine, cause its not like its hard to do, and I just dont like having something wrong with my equipment, but thats me.
If your exhaust system doesnt leak, then you are lean at an idle for whatever reason. Your carb may be dirty, and the pilot or fuel screw, or idle circut passage may be partially plugged, or you may be jetted to lean on the pilot, or your fuel screw may simply need adjusted richer.
Is it ok to run like that? Yeah, it wont cause any major damage, but it can be hard on the exhaust system over time, and it also will make for an unstable idle, and can cause some poor throttle responce, and make it cold blooded if it is caused by a lean condition.
I would fix it if it was mine, cause its not like its hard to do, and I just dont like having something wrong with my equipment, but thats me.
QUOTE (CFM-Z440 @ Sep 20 2009, 01:12 PM)
Backfire on decell is cause by one thing... Oxygen in the exhaust system. It gets there one of two ways, either from an exhaust leak, or from being lean.
If your exhaust system doesnt leak, then you are lean at an idle for whatever reason. Your carb may be dirty, and the pilot or fuel screw, or idle circut passage may be partially plugged, or you may be jetted to lean on the pilot, or your fuel screw may simply need adjusted richer.
Is it ok to run like that? Yeah, it wont cause any major damage, but it can be hard on the exhaust system over time, and it also will make for an unstable idle, and can cause some poor throttle responce, and make it cold blooded if it is caused by a lean condition.
I would fix it if it was mine, cause its not like its hard to do, and I just dont like having something wrong with my equipment, but thats me.
If your exhaust system doesnt leak, then you are lean at an idle for whatever reason. Your carb may be dirty, and the pilot or fuel screw, or idle circut passage may be partially plugged, or you may be jetted to lean on the pilot, or your fuel screw may simply need adjusted richer.
Is it ok to run like that? Yeah, it wont cause any major damage, but it can be hard on the exhaust system over time, and it also will make for an unstable idle, and can cause some poor throttle responce, and make it cold blooded if it is caused by a lean condition.
I would fix it if it was mine, cause its not like its hard to do, and I just dont like having something wrong with my equipment, but thats me.
Correct definitely harder on the exhaust system especially Carbon Fiber....
QUOTE (LTZ470 @ Sep 20 2009, 03:13 PM)
Correct definitely harder on the exhaust system especially Carbon Fiber....
OK thanks for the info guys I appreciate it alot. Im gonna check all the points u guys mentioned. Thanks again.
this happened to me once. I cleaned the carb and raised the idle. problem solved
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.