Hi all,
I finished cleaning my curbs and got stuck on sync'ing them.

the first odd part was that #4 curb never got any vacuum reading. on the afternoon it got better, possibly because I moved the gauges (mercury tubes).

The stupid question is what screw changes what ?
the idle needle is on the right, and each screw changes only the curb to its left, or all the curbs to its left ?
or may be something to the right ??

the reason I am asking is because by now I have them set as two pairs, 2 left and the 2 right ones, not matching, and the idle screw is all the way out. all this in about 2.2K RPM idle.
still not sure which screw changes what.


WHAT AM I MISSING ??


So many thanks to anyone who helps!!


p.s: I have the honda service manual, and its not very helpful. only saying the base curb is #4, which indeed sits next to the idle screw and throttle.

 

Set 1 then 2 to match it. Next set 3 and 4 to match, then there should be a screw to sync the 2 pairs together. Go through process a couple of times to fine tune. Well thats how I did my Suzuki anyway.

 

What he said, only worded a little differently. You have 4 carbs and 3 screws in between them. The screw between carb 1 and 2 balances those two with each other. Adjust them first. Then adjust the screw between carb 3 and carb 4. This will balance 3 and 4 together. Then adjust the screw between carb 2 and 3. This will bring the 2 pairs together with each other.

 

Thanks guys for the explanation.

However I am still stuck with an idle of 3.5K RPM and an idle screw all the way out. The good news is that the curbs are sync'ed...

The other odd thing is that the throttle arm doesn't sit on the curb stop although the idle screw is all out, but there is about a 1 mm gap.
is that normal ??

Thank you again for the help!


Avi

 

Well, I got it to a mechanic. He confirmed the carbs are unsyncable, and started to take them apart.

as a side note, I never actually separated them. only took off the float bowls and diaphragm.

so he did started to separate them, and there was a sync screw without a spring. instead of the spring someone twisted the tabs to get them closer!!

so just incase you can't get the carbs synced, check for this sort of (stupid) things.

my 0.02$ to the forum

 

Thats one of the hazzards of used bikes. You just never know what someone else has done. Well, at least it was a simple fix.

 

Sorry to hear that but good advice for when i go to sync my carbs