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Thou carbs on a 900a4

Posted: Fri Aug 22, 2014 4:50 pm
Author: DaveZ1
Got a set of Z1000A1 carbs to go on a 900 A4 .
Only found out they were thou carbs after ordering the carb repair kit for an A4 only to find the mixture screw is different on the thou carbs and is underneath at the front of the float bowl. While 900a4 carbs have the air mixture screw in the usual place on the top of the carb body. Both carbs are VM 26s though.
Anyway my question is should I use the main jet size and needles for a 900A4 when I rebuild these carbs or is it ok to use the standard thou jets and needle that came with the repair kit.
The bike has standard set up air box and exhausts.
Thanks.

Posted: Sat Aug 23, 2014 6:16 pm
Author: PAULJAC47
Give it a try and see how she goes,dont reckon it would make that much diff,you can always tweak setting and needle clip position...

Posted: Sat Aug 23, 2014 7:41 pm
Author: DaveZ1
Jet sizes are Z1000 Main= 107.5 idle= 17.5 Z900a4= Main 115 idle= 17.5 but the needles are slightly different too.
Think I will err on the side of caution and use Z900 jets and needles dont want to risk going lean and risk "blueing" the nice new headers.
Thanks Dave

Posted: Fri Sep 12, 2014 11:56 am
Author: Z1Boy
I too have a set of VM26s off a Z1000ltd which Im planning to fit on my Z1a. I got a carb repair kit set for a 900A4 and plan to basically convert them to A4 spec. The only difference if I do this is that the Needle Jet [not the needle] will be different, 900a4 is 0.6 and the 1000 is 0.5 [these are not contained in the Kits] does anyone know which is richer, do i need to get the A4 Needle jet to go with the Jet Needle or could I just use the z1000 needle and jet? Std air filter and pipes.

Sorry for long winded question.

Posted: Sat Sep 13, 2014 7:07 am
Author: Z1RII
if you want to use the 1000 carbs on a 900 you have to use the 1000 internals cause the throttle valve and main jet tube is different on the 1000 carbs and will not match with the 900 jets.
install the stock 1000 carb with stock jets and it will run, don´t mix up the jettings.

Posted: Sun Sep 21, 2014 9:38 pm
Author: dave cullen
sorry mate, I know now we have had conversation, ie no probs interchanging them, apologies, late night, too much beer
dave