Slide valve cut out

[David Isted]

Hi all I’m after some advise with regards to the slide valve cut out on my minuki 26mm carbs, my question is when bench synchronising the carbs should the cut outs initially all be set to the same measurement as laid down in the service manual. My bike is a 1978 GS750e

[zed1015]

They all need to be set at the same height on the bench as a base line with the adjuster screws being around mid way travel on their threads to allow for sufficient adjustment either way.
Once on the bike you need to vacuum sync to ensure each cylinder is producing equal amounts of work.
Once done the slide heights are likely to vary slightly.

[David Isted]

Thanks for the info, the last time I tried to use my vacuum gauges I ended up with number 3 cylinder running cooler on idle but heating up correctly once the revs were increased, maybe I was a bit to heavy handed with the adjustments. I have set all four slide vales to the same position and the carbs are back on the bike, will give it a try on Thursday to see if I have improved thing or just made it worse

[zed1015]

Thanks for the info, the last time I tried to use my vacuum gauges I ended up with number 3 cylinder running cooler on idle but heating up correctly once the revs were increased, maybe I was a bit to heavy handed with the adjustments. I have set all four slide vales to the same position and the carbs are back on the bike, will give it a try on Thursday to see if I have improved thing or just made it worse

vacuum balancing won't affect fueling or mixture.
That sounds more like an idle fueling issue.
Probably pilot jet blockage,over rich on the mixture screw or even electrical problem on the ignition side, faulty plug etc.

[David Isted]

Thanks for the reply, will check it all out.