Vacuum line needed?

[njemnjem]

I have a 92 r100 with the vacuum lines from the carb to the air box. Is this useful? Could I just take off these air lines and cap the vacuum spigot. I got to wondering when I was balancing the carbs, which involves pulling off those lines and connecting a vacuum gauge which doesn't allow any actual air flow. That got me curious and I blew into the vacuum line and it allows a little air to go through. Does that mean I have an air leak or is it supposed to have a little air flow?

Thanks
Vacuum headed about vacuum hoses

[20774]

Most people plug this system, especially when it's out of warranty. Information about that is here:

http://bmwmotorcycletech.info/pulseair.htm

[AnnapolisAirhead]

I have an '83 R100T and had the same question, plus the metal pipes from air cleaner to cylinder head. I asked my local dealer about it choking the system and they suggested I consider an 'Emissions Kit' to effectively remove both the vacuum line from the carbs and the metal pipes to the air cleaner. I can't recall the price for the kit, but it was not expensive (I seem to recall it was $7.00--I like Bob's, but very few things that inexpensive there), a couple rubber plugs for the air box where the pipes were, a pair of tine screws to replace the vacuum lines on the carbs and a pair of larger metal threaded plugs for the cylinder heads. In the air box, you remove the metal diaphram valves (I guess these would be the equivalent to an EGR valve).

Afterwards, I checked the synch of the carbs and the bike idles much smoother (I had some problems with surging). Also, I have a K&N filter that fits nicely in the factory air box. What ever will help my bike run cool, I'll consider it. This kit and the K&N filter definitely help (I've done similar things to a number of Jeep Cherokee straight 6-cylinders to some heat problems.

I've heard these were first introduced as a requirement for California, but not sure that is 100% correct. Anyway, I did remove it and happy ever since.

[njemnjem]

Thanks for the info guys. Some good info in that tech article. I think I will disconnect and close off the vacuum system. Since I can get a little air to go through there, and I doubt that's right, it just seems like a place for a vacuum leak.