Dies when idling

[HenryCrew]

Hello,

Picked up a 1982 xs 400 last week, starts fine but I've had to turn the idle revs way up because it dies if idling at low revs. The battery is too low to use the electric start so I'm replacing that however that. The air box was swapped for air filters by the previous owner so I'm thinking carbs may need rebalancing? or cleaning?

Has anyone had these problems? I'm not all that mechanical so could use all the help I could get! also if anyone knows any mechanics in the south of England that specialise / are good with XS400's I would love some names!

Cheers!

 

[JARichmond]

Carbs are a great place to start. Filter swapping will usually lean out your mixture pretty significantly, so upping your main jets to the next size up (or two) will usually solve the problem.
You can also check your spark plugs. A lean mixture will leave white residue on your plugs while a rich mixture will leave soot on it. Replacing your plugs (BPR7ES for SOHC, BPR8ES for DOHC) is also a great place to start and will give you an idea of how your bike is working now.
Also, as always, welcome to the forum!

 

[ensoroni]

are there pods on the carburetors? I had a similar issue caused by my pods blocking some idle vents. If there are pod filters on your carbs I would check to make sure they don't have that inner lip that can block some air vents that will cause your back to have idling issues.

Mine would idle fine then suddenly shut off.