Erratic Vacuum Reading On One Cylinder

[moose_]

Finally after about a year of rough idling I've managed to blag a loan of some Carbtune pro vacuum gauges to try and balance my throttle bodies. Now, I'm fairly mechanically inept but managed to get them on and was getting a reading quite close across all 4 pots. Cylinder 1 was reading slightly out from the rest and was jumping about a bit so I tweaked the screw which brought it in line with the rest but it was still jumping about a bit. Cylinder 3 was twitching a wee bit and the other two were rock solid.

Would this indicate the valves need adjusted or is there something else I should be looking at?

The bike is a GSXR 1000K3 if that matters

Cheers

[BudgetBoy]

As long as you get them within 2hg of each other that will be ok. i have the carbtune and they do jump about on some bikes.. you need a steady idle.. have you increased the idle up to about 2k? Doing it on idle wont help matters, the carbtune needs a steady throttle.

Balance 1&2 so they are equal, then balance 3&4 so they are equal , then balance them together.

[moose_]

I was trying it on idle going by the suzuki manual. I'll try again with more revs

Thanks

[Conica]

Should've bought a Dyson.

[Thom_1991]

Does this make a big difference with efi bikes? It was night and day on the (carbed) Fazer.

[moose_]

You sure the dampers were in the vacuum hoses?

nope, not sure at all. I borrowed the gauges from a mate and just plugged the hoses onto the throttle bodies. I did spy some black plastic bits in the box but just thought they were adaptors.

[moose_]

Don't think there was. I'm going to try again tomorrow so will double check. Thanks