running problems

[Lesley8434]

I,ve had a storm for about six months. It was to and fro the shop for the first two months as they tried to sort out the running problems which they did apart from a slight miss fire between two and three thousand which is getting no better but is getting worse. Any ideas. Its a 2003 model. jim

[MacV2]

I,ve had a storm for about six months. It was to and fro the shop for the first two months as they tried to sort out the running problems which they did apart from a slight miss fire between two and three thousand which is getting no better but is getting worse. Any ideas. Its a 2003 model. jim

It could be a host of things TBH but one place to look which is often over looked is the Petcock Diaphragm...Even the tiniest pin hole or tear can lead to running issues...

It could be the coils breaking down, bad plugs or just in need of a decent carb tune...Is it running a std air fillter, maybe it's been rejetted in the past for different cans, which have been removed prior to sale but the carbs not put back to spec...

Have a read through various carb subjects here... viewforum.php?f=31

Bit more info from you re what cans & air fillter required please...

[tony.mon]

Misfiring when holding it steady at those revs or while accelerating?
You aren't describing a dull thud under the tank as you pull away, are you?
Could be a carb cough if so.

[MacV2]

Ahhh 2003 ...has it still got the PAIRS stuff on it ?

[Commando77]

Mine does that at steady low speed running and tiny throttle opening around 2 to 2.5. Got so wrapped up sorting another issue I forgot the PAIR mod, something I'd meant to do when I stripped her down. Usually a squirt with the throttle and it settles down for a bit. I just put it down to those big carbs and a bit of richness.