balance tube between intakes 71 xs1b

[bill932]

I notice on my 73&80 650s there is no balance tube ports molded in the head like on my 71. Could this tube be removed and the ports just used to balance carbs?

 

[DogBunny]

Yes, you could do that, but it's kind of a lot of trouble. You really don't need manometers to balance the carbs if you are running dual exhausts. Just put your hand a couple of inches behind each exhaust while idling, and sync by equalizing the pressure that you feel. Perfect sync isn't necessary, and besides, perfect sync is a moving target, it moves around based on several changing conditions.

 

[bill932]

Thank you

 

[gggGary]

PS NEVER trust that crusty old rock hard rubber balance tube, remove and replace. The local auto store has some heater hose that fits perfectly.

 

[bill932]

Do I need balance tube at all?

 

[Jim]

Nope. It was deleted on the 447 motors.

 

[GLJ]

Nope. It was deleted on the 447 motors.

Deleted starting with the 72s. Most likely when the changed the left exhaust tappet cover from 3 hole to 4.

 

[Jim]

Deleted starting with the 72s. Most likely when the changed the left exhaust tappet cover from 3 hole to 4.

Yeah.... knew it was done prior to the 447, just wasn't sure when. Figured it was best to just state the part I knew.

 

[DogBunny]

You can remove the balance tube and cap off the ports, but don't do anything that isn't reversible. Those balance tube heads are rare and valuable, and should not be molested.
I personally think the balance tube is a good thing, and I'd keep it. At the very least it doesn't hurt anything. If it did, they would have come out with a bulletin on it.

 

[bill932]

I will remove tube, balance carbs using ports, and cap off. See if I notice any difference. May take a week or 2. Thanks for all your help.

 

[bill932]

Removed balance tube. It was as hard as a piece of plastic. Balanced carbs using balance ports. Caped ports off. Did not notice any difference in performance.