Topic: Where to tap a vacuum line?

[Dolomite]

I need to add a vacuum line for the crankcase since I am running stacks. Does anyone know a good unobtrusive place to tap into for a vacuum line? Only idea I have so far is to tap small barb nipples into the stacks to run a vacuum from.

[bryanj]

Why do you need a vacuum line?

[pjlogue]

If you try and tap the intake vacuum you will alter your carb mixture if you are allowing ANY volume of air to bypass the carb throat where the gas/air mixing takes place.  These engines are not designed for a PCV system. 

-P. 

[Bodi]

Odd request. What is the vacuum for?
Anyway: you need a port between the throttle plate and the intake valve. There won't be vacuum in the stacks... at least not enough to do anything with, and useless for carb balancing.
You can connect a vacuum servo of some sort like an automatic petcock, or a gauge/sensor, with no issues. Just don't allow much constant flow.

[robvangulik]

I suspect you  mean a crankcase breather hose...?

[bryanj]

Which is why my original question to the poster rtill stands, without a reaso we are all peeing into the wind!!!!

[Dolomite]

Yes for the crankcase breather. Currently its venting to atmosphere through a filter but I suspect I am still getting some blow by. I wanted to try to add a universal pcv or small catch can but I would need to plumb a vacuum line from somewhere.

[bryanj]

Dont do it, the original 750's vented to atmosphere and the complication you will add would make tuning and running an absolute nightmare

[Don R]

 Us drag racers use an angle cut nipple in the exhaust to make some vacuum, if you have a 4-1, that might be useful if you can get behind the baffle where there's not much backpressure. 

[Bodi]

You can vent it in a stack but you'll just gum up that carb with oily goo. There are little "pod" filters for the vent line that collect the oil vapor and just need a solvent wash every few thousand miles, or just route it down to end behind the engine somewhere. Barring some catastrophe it won't put out enough oil to cause traction problems for the rear tire, just the 'smoke" and a drip every now and then.