Well I've finally got round to taking a look at this and why the damn thing won't start.
It's not been run in months so wasn't keen on starting.
If I disconnect the fuel line going in to the carbs I get fuel coming out when I crank the engine, so presumably that means the fuel pump is working ok.
I replaced the vacuum line to the fuel tap in case there was a leak there causing the fuel tap issue
Also replaced the fuel line from the tank to the filter as I had to shorten it some time ago as it had perished, this meant there was a bit of a kink in the pipe that could have been causing trouble
Had to dribble some fuel in to the carbs to get it to start up, but eventually got it going and it ran fine on prime
Switch to main fuel and after some minutes the idle dropped from 1000 to around 500 for a while and then conked out. Restarted ok and ran fine with some revs on but still slow idle and stalled after a while at idle. Back to prime and it ran fine again idling at 1000.
I can't believe it's the fuel pump if it runs fine on prime, but can't see what the issue can be with the tap as it had a new seal kit not that long ago.
Given Lee's point above, I found this lurking at the back of the garage
Hmmm, image not working, how about this? https://www.dropbox.....39.09.jpg?dl=0
Think it's either and R1 or R6. Big bugger compared to the vacuum jobby on the divvy. Presumably the bigger pipe is the inlet and the smaller one the outlet? If I were to fit this, will I need to mess about with the carbs to get it to work ok, or should they deal a different fuel pressure ok?
Edited by ChrisG, 01 August 2017 - 07:51 pm.
1992 Mk1, 76k miles, Hagon springs, MTC exhaust, 4½ gears Gone now
2009 900 abs, 42k miles, Yamaha heated grips, double bubble screen, R&G crash bungs, scottoiler, Autocom, 1500 lumen LED spotlights.