When I roll out of the throttle or down shift it wants to spit and back fire a lil. The spark plugs seem fine. Just to let you know if it helps its a 97 with a carb. Its only been doing this for about 3 or 4 weeks. Also if I leave the choke half out it does not do it at all. So if anyone knows anything that will help that would be great.I have to get it to stop bc the back fire is harmfull to the motor and it sounds bad lol. Thanks
2007-06-20 04:35:34 · 8 answers · asked by keyblader2 1 in Cars & Transportation ➔ Motorcycles
My '01 backfires a little bit. It's pretty normal if you slow down by disengaging the clutch instead of using the brakes. If you want you can have the carb rejetted. That might help. Or you can adjust the idle on your carb.
2007-06-20 04:39:54 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Sounds like you have a 'lean' condition that the choke is compensating.
My Honda cruiser has vacuum lines that operate the petcock and a PAIR valve ( fresh air injection to exhaust) . There are also vacuum plugs over the ports where the carbs are balanced. If any of these lines or plugs leak air I get an off throttle backfire. Fortunately they are cheap and easy to replace.
An off throttle backfire can also be caused by an exhaust leak.
2007-06-20 06:36:03 · answer #2 · answered by Anonymous · 0⤊ 0⤋
I had a 97 1100 Shadow Spirit, and now ride a 2000 of the same and with both there is a crack/pop of exhaust as this is normal for those engine ( I have Vane & Hines pipes but the stockers also do it..just cannot hear it with them as much). Also, if you are running NONE stock exhausts then you probaly need re-jetting. If you have not had the carbs synicronized then that could be part of it. It sounds like your running lean (NOT GOOD for the valves, etc.) and any one or combo of the aforementioned could cause it.
2007-06-21 04:37:24 · answer #3 · answered by ramarro smith shadow 4 · 0⤊ 0⤋
Sounds more like there is some water in the tank. Put a can of "dry gas" into the tank, and see if that helps. Having to keep you choke out a bit, means that the gas/air mixture isn't the right levels, again, which sounds more like there is water mixing in with the gas. Since your tank isn't a sealed tank, water vapor can occur, just by letting it stand outside on a humid day, after the engine gets hot.
2007-06-20 06:01:14 · answer #4 · answered by auditor4u2007 5 · 0⤊ 0⤋
Your carbs have an "air cut off" valve.
They restrict the air supply (which richens the mixture) upon deceleration, to prevent back firing due to a lean fuel mixture.
Bad gas gums up the valves, preventing them from moving.
The fact that the problem goes away when you apply the choke, confirms that this is the problem.
The carbs should be removed and cleaned (especially the air cut off valves).
Specify this to the shop if you bring it somewhere to be repaired.
2007-06-20 06:30:02 · answer #5 · answered by guardrailjim 7 · 0⤊ 0⤋
most likely an air leak at the carburators, get a can of carb cleaner from the auto parts store and fire up the bike, spray quick shots of cleaner around the rubber boots at the carb. and listen if the engine picks up or drops off, you have either a loose boot or a crack in the boot
2007-06-20 06:04:31 · answer #6 · answered by Anonymous · 0⤊ 0⤋
You have an air pump to aid with emission control. When backing down the air forced in is what is causing the backfire. A good mechanic can adjust that. Or you can find the small hose and cap it off which will stop the backfire but cause your engine to run rich.
2007-06-20 05:15:46 · answer #7 · answered by Dogbettor 5 · 0⤊ 1⤋
probably time for some carb work.having to Leave the choke out a little means the air mix isn't righ.
2007-06-20 04:43:25 · answer #8 · answered by randy 7 · 0⤊ 0⤋