Carb balancing (AGAIN)

[PaulD]

My Kats motor is a lumpy, rough thing which isn’t very pleasant to ride. I’ve done the valve clearances and checked the ignition timing, fitted new plugs, oil & air filters and changed the oil. I tried to balance the carbs when I first got the bike after stripping, ultrasonic cleaning and adjusted the float heights but I struggled to match all four carbs on my vac gauges. I did notice when I bench synced them that on no3 carb (the base carb) the butterfly wasn’t fully closed like the other three? I couldn’t figure out how to adjust this and couldn’t see any method of doing so. Could this be why I can’t match the other carbs to the base one? What am I missing guys?

[Kryten]

I am going to put a set of BS32SS’s together this week. I’ll have a look..
As far as I am aware, the idle speed adjuster operates on that carb so that you lift all 4 butterfly’s together to adjust the idle speed.

Either the throttle cable or the idle speed adjuster is holding that one open. Unless there is an assembly issue or damage to that butterfly

[PaulD]

Thanks Jim much appreciated, I know for sure it’s not the throttle cable so I can rule that out. It looks like I’m going to have to pull the buggers off again!

[PaulD]

Some cross checking of my vac gauges today revealed that my eBay bargain gauges are bloody useless I warned the bike up and had it ticking over reasonably smoothly at 1200rpm, I then connected my gauges one at a time to one cylinder and I got a hugely different set of readings on each gauge? connecting Fossies set of Morgan steel rod gauges each gauge gave the same reading. All I've got to do now is remove the tank and have another crack at balancing the carbs using the foss meisters gauge and I'm good to go. I ain't doing it today as the suns still shining and I'm going to give it a dam good thrashing

[PaulD]

Well the ride out didn't go very well and I turned around after six miles or so with the bike running very rough and feeling unpleasant to ride. As it was up to running temp i whipped the tank & seat off and set too with Fossies vac gauges. Fifteen minutes later and the bike is running as smooth as a very smooth thing straight out of the smooth factory as a bonus it is now mechanically quieter by a fair bit. A test run of thirty odd miles shows the bike is now running the way I think it should with a lot more urgency off the throttle and virtually no vibration at speeds of up to an indicated 80mph.
Happy? you betcha. Thanks to everyone who helped out.
I'll just enjoy it now until the winter comes and then I'll take it off the road and cure it's smoking habit.

[Kryten]

Well the ride out didn't go very well and I turned around after six miles or so with the bike running very rough and feeling unpleasant to ride. As it was up to running temp i whipped the tank & seat off and set too with Fossies vac gauges. Fifteen minutes later and the bike is running as smooth as a very smooth thing straight out of the smooth factory as a bonus it is now mechanically quieter by a fair bit. A test run of thirty odd miles shows the bike is now running the way I think it should with a lot more urgency off the throttle and virtually no vibration at speeds of up to an indicated 80mph.
Happy? you betcha. Thanks to everyone who helped out.
I'll just enjoy it now until the winter comes and then I'll take it off the road and cure it's smoking habit.

Whooo Hooo!

Good to hear that.