How did you clear the breather Harris? Compresed air and carb cleaner. I only ask as I cant seem to get a wire or pipe cleaner through, so I'm guessing they're drilled at 90deg to each other

Mikey, ECU is AEA, but i need all wiring etc. I'm reluctant to buy back stuff i already sold though I'll need thermostat etc. and the work putting all that in could probably be spent trouble shooting carb issues. If it was all to hand, I'd maybe do it. But waiting/collecting all things and then doing it would allow enough time to sort carbs i would have though

have you taken them apart and cleaned them out Simon?

I've had a go yeah. But i can't seem to get anything down the breathers. I'm not sure if thats because they are blocked, or whether they are drilled at acute angles. I can't seem to find a cut through diagram of the carbs so can't be sure. All other pipes are clear etc, and so are the main and idle jets as they are new.

Just for future search reference , 1994 Honda cbr 600 carbs :-D

down which breathers? Get some pics up!

You can tell where there are adjoining bores in the carb bodies, because the drill point is blocked off with a plug, which is basically a ball bearing punched in.

The breather channel from the plastic fitting goes horizontally, so look along the body of the carb for any clue to where it goes. It's only possible to drill a bore in a straight line. You'll find where it reaches the other side of the body is the head of a ball bearing sticking out the surface. Look on the side of the body and in line with it is a vertical rib in the casting.. So there at the bearing head is your 90-degree corner.

When checking for blockages, i blow down a suitably sized bit of tubing pressed into it and listen for air where it should exit. In your case it's going to be into the fuel baths, so you'll need to remove them and listen for air coming out from around the floats (whilst they're off, check the jets/cavities are clear too).