93 transalp running problem

[deebee]

my 93 xl600 transalp has developed a fault with the running. When riding it has an intermittent fault where in it loses power and wont rev properly, and to my ears it sounds like its fuel starvation as it makes a kind of baaaaaaaaaaaahhhh baaaaaaaaaaahhhhh noise when the throttle is opened, and wont rev properly and is very low on power. (no it isnt a sheep stuck in the air filter)

once the fault starts it stays low on power and wont rev, but every now and then it clears and gives full power again, but only breifly maybe 1 or 2 seconds then goes back to low power/not revving again.

ive looked at the fuel tap and checked the tap diaphram. cant see anything wrong.

the air filter isnt blocked, nor is any of the ducting to the carbs.

all the rubber seals and gaskets seem ok, and the rubber joining pipes and jubilee clips all look good.

all the cables are adjusted and operating properly

the fuel in the tank is all fresh.

im only ASSUMING that its a fueling problem, i havent checked the igniton system at all, other than to check that both cylinders have a spark, which they do.


any advice??