Carb synchronisation

[Gavin]

Morning guys
Yesterday I decided to set the carbs up.I set the slides up using a piece of wire as stated in the manual ( had to use 0.6 mm ) . So when setting the vacuum No. 1 carb no problem plenty of adjustment available however No 2 to 4 there is hardly any adjustment available, it is as if they are almost at the bottom of their adjustment in the initial bench set up. All the parts eg needles have the same part numbers, needles are set to slot 3.
Checking the movement of the adjusters out of the carb body they all have the same amount of travel and are free moving
Any thoughts on why this is happening.


Gavin

[warren3200gt]

You need to adjust the others to give you more adjust on the issue ones. This will allow the issue ones to drop further. Then bench sync them again then vacuum sync them again

[Gavin]

Sorry Warren3200gt
I don’t quite understand what you mean.
As in how to adjust them further. When doing the static bench set up you can actually see the adjusting screw on No. 1 carb is not as low as the other 3 carbs.

Gavin

[warren3200gt]

If im understanding your issue, raise the other three so the screw adjusters are roughly the same. This will allow the return spring to lower all four. Assuming the idle adjuster is backed off enough.

[Gavin]

Idler adjuster, bugger I didn’t back that off, cheers I will look at that

[Philippe]

Hi Gavin

perhaps my reply is too late but, before bench adjusting the slides you have to set the idler adjuster screw halfway. By doing that you have plenty of play to adjust it afterwards.
Bench synchronising is something that requires a lot of patience. Don't expect it to be correct from the first time. Do it when you're calm and don't be afraid to start all over again and again.
If done right and when the carbs are mounted, you only need to adjust a tiny little bit when using the vacuum gauges.
And mind when using vacuum gauges that those don't always show the correct reading...there might be a difference on the same carb when changing that carb from one gauge to another!
Good luck!
GrtZ
Philippe

[Gavin]

Thanks for the advice Philippe, I decided to take a few days to do other things before taking the carbs off again, so will do as you say when I get back on them

Gavin

[kev edwards]

When you do get round to doing it correctly and in the right order you will realise how easy and logical it really is, end result is to have the adjustment screws around half of their travel distance, slide heights can also be done when on the bike, but we will save that for another day.