I recently bought a badly (= nearly not at all, but hey, it was a bargain... :) ) maintained GS; now I need to synchronize the carbs, besides some other work, such as valve adjustment and so on. As far as I know, all parts are as they came from the factory.
I've got a good garage where I'm doing the job, they've got the airflow meters and the other required gear down to a pat - and I even talked one of their guys to watch over my shoulder so I won't break anything.
Unfortunately they don't have a manual for that bike. So I would really appreciate, if someone could tell me, how much underpressure (is that the correct term in English, btw?) there should be?
This seemed to be the best forum available for asking this kind of stuff... and I think I've hitten most of any GS pages available.
Thanks in advance!
Cheers,
Jarno[/i]
Welcome!
You should have the valves adjusted while the bike is cold, and before you synchronize the vacuum between the two carburetors, as the valve adjustment may affect the synchronization. That said, all you have to do is balance the vacuum that is being drawn between the two cylinders.
Thanks!
Yeah, you're right about the valves to be adjusted first.
I started the project yesterday evening with that valve job, but they didn't have that kind of shim discs, so I had to leave the bike there, as Thursday was a bank holiday down here and I couldn't get the discs today.
I've got two stores who import Suzukis (and do maintenance) here lined up, they oughto've those, so I'll finish up with that valve job and do some other minor work first.
The carbs would have to be the last one anyway since the valve adjustment will have some effect on how the carbs work.
I just thought that if there was some "ideal" value or range, It'd be good to know.
ok, super simple way to sync the carbs with carbs off bike right after cleaning or rejet, take some thin gauge solid core wire. the type that when the insulation is removed, you have one stiff string of copper. strip the wire try to keep it straight as posible with no bends or kinks. you only need it about 3 inches long. If you have a guitar string its perfect. on the carb with the Idle stop screw start turning it up idle till you can just fit the string/wire between the bottom of the throttle plate and the carb throat wall. alittle drag is prefered, but an equal amount on both carbs is what your looking to acheive. adjust the little screw on the linkage near the cable connection to open or close the other plate to get the wire to fit the same. once done your synced, back the idle stop screw back down close to original area. mount carbs and fire it up let it warm up and reset the idle to desired RPM. Vacume gauges/manometers give you numbers or levels to follow and its all just to make sure both plates open the same amount the same time. i like the feeler gauge method i just described, you can also do it by looking through the carb throats and comparing the amount of light coming from the back side and even it out the same way.