getting 1250 analyzed on the computer to find fault

my 1250 runs fine when cold, crisp as but when it warms up it surges and feels like it wants to run rich down in low revs, the exhaust pipe is sooty



have asked the shop but they are reluctant to do this, its like they cant be bothered


can the bike shop plug into computer to tell me what the fault is ?

The Bandit doesn't have an OBD II port or wide band exhaust sensors to provide the info you're after.  You might be able to "read" the spark plugs, but getting them out is not an easy task.  Your best bet is a proper dyno tune where they can measure the actual exhaust gases and getting everything to run as close to factory spec as possible, this will probably take a couple of hours/$100 bills.

A number of us have opted for "opened" airbox lids, aftermarket headers and slip-ons, as well as secondary butterfly removal and throttle body sync.  This is often coupled with an after-market computer such as Dale Walkers Supertune or a PC-IV or a reflash of the OEM computer, and more of those $100 bills.

Why not do a throttle sync first? This is easy to do with the right tools. I use a Morgan carb tune and the bike runs very well after it is done.

If you have a vacuum leak on the throttle bodies it may cause a similar condition

I pulled plugs, all are sooty so replaced with new plugs, also changed coils as the old ones were no good

The bike runs fine when cold and always ok at top end so its not a lacking in fuel

I was wondering if the secondary butterflies in carbs, the ones the computer changes may not be working properly or opening enough because when the bike warms up it feels like the chock is on and runs rich down low

would it be easier to just remove the secondary butterflies in carbs

what are the pros and cons by doing this

stan2nz wrote:I pulled plugs, all are sooty so replaced with new plugs, also changed coils as the old ones were no good

The bike runs fine when cold and always ok at top end so its not a lacking in fuel

I was wondering if the secondary butterflies in carbs, the ones the computer changes may not be working properly or opening enough because when the bike warms up it feels like the chock is on and runs rich down low

It has Throttle Bodies stan, not Carb's

Personally I'd be getting it right before you do any mod's otherwise if it's still no good (that would be most likely) you'd want to go back to standard to fault find