Got the 82 xs400 running and found my first problem. I have been riding the bike for a week to work and back with very little trouble until the bike started popping on decel and would quit when the revs came down when stopping. It only does this once in a while i.e warm afternoons (12deg C or around 60deg for you american folks). The bike also experiences a hanging idle (not sure if that has anything to do with it). Any advice would be appreciated.
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Bike pops and quits
- Thread starter chris
- Start date
You're running too lean. Have you modified the bike at all? Lean conditions typically improve as temperature rises, but you may have a leak somewhere. Alternatively your carbs might be dirty and after some use a passage has become blocked. Ultimately I need more information. With the information you provided I would bet on a leak having developed. The more you used the bike the more things moved around; I would suspect carb boots or the intake tract.
Hi bcware, I have not modified the bike in any way. As far as I know the bike is pretty much stock. When I bought the bike, the carbs were supposedly freshly cleaned. An air leak is my first guess also. The carb boots look cracked, not sure if they are just surface cracks but I ordered a new set just to be sure. The bike seems to run fine in the frigid Canadian morning but it has trouble on the afternoon. Also the problem seems intermittant. One day it was giving me trouble, and the next day no problems. I have been running seafoam and high octane gas through the carb since i got the bike. Let me know if anything else comes to mind. Thx
I replaced the boots on mine as well just in case; new rubber seats against the motor better too. You'll be taking everything off when you put the new boots on anyway, but that is what I would have suggested. Take everything off from boots to intake, inspect, clean as necessary, and reinstall making sure everything is snug. There are many clamps that could come loose along the way or develop a crack.
Should this fail to cure the problem I would then move on the carbs and simply remove the jets and give it a quick cleaning with compressed air and carb cleaner. Let us know how it goes when the parts come in.
Should this fail to cure the problem I would then move on the carbs and simply remove the jets and give it a quick cleaning with compressed air and carb cleaner. Let us know how it goes when the parts come in.
If you suspect a vacuum leak, spray some carb cleaner around the intake boots while running. Any change in idle means a leak.
I'd say you likely have dirt in a carb, something left over that found its way into a passage. check the float valves. I had crap behind the float seat and had to pull it out to clean it. Hanging idle could mean vacuum leak or lean condition also.
In my experience, the carbs sometimes need to be cleaned several times, especially when getting a bike on the road for the first time. Crap in the tank, crap in the carbs. Also, may times a "cleaned" carb means someone took the float bowl off and sprayed carb cleaner into what they could see. Do yourself a favor, Pull it apart, every thing that can be moved, including the tube running down the center of the carb. Blow everything out with air, make sure all ports are clean. It is not a hard job. The diaphrams can be challenging but are straightforward.
I'd say you likely have dirt in a carb, something left over that found its way into a passage. check the float valves. I had crap behind the float seat and had to pull it out to clean it. Hanging idle could mean vacuum leak or lean condition also.
In my experience, the carbs sometimes need to be cleaned several times, especially when getting a bike on the road for the first time. Crap in the tank, crap in the carbs. Also, may times a "cleaned" carb means someone took the float bowl off and sprayed carb cleaner into what they could see. Do yourself a favor, Pull it apart, every thing that can be moved, including the tube running down the center of the carb. Blow everything out with air, make sure all ports are clean. It is not a hard job. The diaphrams can be challenging but are straightforward.
