Adjusting 1973 carbs before sync

[crxnug]

I have rebuilt mt 1973 carbs, i have a questions regarding adjusting the slide , is the suppose to be any play up top, also how much gap should i have before putting carbs back on bike and start sync process, any help would be must appreciated

 

[Twobond]

I have been using feeler gauge to synchronize my carbs. After the rebuild before you put them back on the bike. No need to do anything else.

 

[Loki]

I have rebuilt mt 1973 carbs, i have a questions regarding adjusting the slide , is the suppose to be any play up top, also how much gap should i have before putting carbs back on bike and start sync process, any help would be must appreciated

The aduster bobbins on top of the carbs have a spring built in to them which gives a small amount of play, this why you synchronise the slides with a small drill, size isn't critical 3-4mm is fine, and you can easily judge how tight the drill slides under the slides to get them all the same, this will give a good starting point which many people find is near enough, just depends how particular you are!

Loki

 

[dirtdigger]

Bench sync has very little purpose other then to get it running before a proper running carb sync. Each cylinder runs different, this is why a running carb sync is so important. Some cylinders are capable of more vacuum then others depending on how the condition of each cylinder. You balance the vacuum on all the cylinders so they are contributing approximately the same amount of power in the engine. This results in the smoothest power delivery and the smoothest idle. You also want to see how the vacuum acts when raising the rpm and how they respond on decel when throttle closes. This helps to determine engine condition, jetting and helps when you are fighting a hanging idle and you can make sure the slide is opening even on all cylinders as the throttle is opened. The closer you match the vacuum on a running engine the smoother the idle and the smoother the engine will run through the whole operating range.