Linking the intake manifold boots.....

[Guest]

I think I've seen something on this in the past. What is that deal where you link up the cylinders with little tubes using the access ports in the intake manifold boots. Something about it smoothing out low rpm performance. And on that note, what are those little ports for anyway? Thanks.

[loud et]

It's called a carb sync.

[phydeauxmutt]

You connect vacuum gauges to those ports to make adjustements so all cylinders are pulling the same vacuum.

It is recommended to check valve clearances BEFORE doing a carb sync.

[Grimly]

I think I've seen something on this in the past. What is that deal where you link up the cylinders with little tubes using the access ports in the intake manifold boots. Something about it smoothing out low rpm performance. And on that note, what are those little ports for anyway? Thanks.

The idea of linking all the vacuum ports up is to mimic the effects of the Yamaha YICS system.
Some say it works, others say it doesn't. Me, I'm in no position to try it, as I no longer have the factory carbs on either of the GSs.
What I do have is a YICS-equipped Yamaha, and it seems to work on that, but Yamaha themselves produced engines with it and without it, so meh.

[bobgroger]

I remember back in the day my KZ900 had the ports all connected together with vacuum hose and "t"s. Dealer said it made carb sync more tolerant as all the vacuum would be the same. Don't know if it helped or not, but I never synced the carbs and it always ran great.

[Agemax]

I run my GS1000 with the ports permanently linked, 1+4 and 2+3. Definately smoothes out idle but dont think it helps out any other way.
Also makes synching a much quicker job as the adaptors are permanently attached.