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TUNING VM28SS CARBS (with AIR & FUEL screws!!!)
Posted: Sun Oct 02, 2016 7:22 pm
Author: Pigford
Whats the correct settings/method for tuning VM28ss Mikuni's - off a GS1000S
Have done plenty of carbs over the years, but not with BOTH "Air & Fuel" screws combined on the same carbs.
I know how they work, but they're causing 2 x the headache
Any tips on which to set first or which one to change first, etc
Posted: Sun Oct 02, 2016 7:41 pm
Author: warren3200gt
For a 650 with both fuel screw is set to 3/4 of a turn out and airscrew is 1 3/8 out, however, I've had much better success by screwing the fuel screw closed and just using the airscrew.
good luck, bloody pain ain't they, what was mikuni thinking?
Posted: Sun Oct 02, 2016 8:29 pm
Author: Pigford
Cheers lad - that sounds like a plan, disabling one system and concentrating on t'other
Posted: Sun Oct 02, 2016 9:20 pm
Author: zed1015
For the 28mm carbs the std setting for the GS1000 is.
1-1/4 turns out for the air and 3/4 turns out for the fuel which should also work or be a good starting point for the zed.
The carbs I bored out to 29mm for the Z900 café were 26MM GS carbs and run great on similar settings.
The fuel mix screw is very sensitive and is mainly to perk up just off idle low speed running and may need leaning off slightly if fluffing occurs during prolonged low speed cruising (under 50mph in top).
Posted: Mon Oct 03, 2016 6:14 am
Author: Pigford
zed1015 wrote:For the 28mm carbs the std setting for the GS1000 is.
1-1/4 turns out for the air and 3/4 turns out for the fuel which should also work or be a good starting point for the zed.
The carbs I bored out to 29mm for the Z900 café were 26MM GS carbs and run great on similar settings.
The fuel mix screw is very sensitive and is mainly to perk up just off idle low speed running and may need leaning off slightly if fluffing occurs during prolonged low speed cruising (under 50mph in top).
Cheers Rob -
Youz da man 
Posted: Mon Oct 03, 2016 7:17 am
Author: warren3200gt
If you go down the closing off the fuel screw route, be careful not to over tighten them. The pointy tips break off real easy and then your in whole other world off grief.
Getting the broken tips out is a b******d !
Posted: Mon Oct 03, 2016 11:12 am
Author: Pigford
warren3200gt wrote:If you go down the closing off the fuel screw route, be careful not to over tighten them. The pointy tips break off real easy and then your in whole other world off grief.
Getting the broken tips out is a b******d !
..........got the T-shirt for that one... Allens do spares tho!!!