Surging @4000 rpm

[naughtyG]

Thanx for the heads up. I had a chat with Mark, and I'm gonna start by checking my float levels, although it's kinda unlkely for these to get out of whack. I'll also try putting the shims back on the needles (they were fitted when I got the bike) and I removed them to see if I could improve mpg by going more 'stock' since there are no other mods on the carbs or exhausts. :confused2:

Two thoughts I've had:
- the bike being an '86, it's possible that my float needles may not sit right cos of wear and tear, so dismantling the carbs to take a good look is gonna be a must soon.
- also, it sounds/feels more like fuel starvation than overfuelling, so I've been wondering what the deal is with that little filter/cannister that's fitted to the gas tank vent tube - if that was dead/blocked up, could it create enough of a vacuum in the tank to screw with fuel delivery? :ummm:

Any further thoughts will be appreciated, as this shit is driving me crazy! Also my Morgan Carbtune vacuum gauge should arrive any day now, so I'm looking forward to find out how well or not my carbs are synced...

 

[Hime696]

UPDATE: I found the souce of the surging. The float bowl vent tubes were routed down behind the engine. Storloc had posted a picture of the tubes connected to the top of the airbox. Well I connected the vent hoses to the airbox. I rode the bike to work this morning and the surging is gone. Thanks for all of the replies.