Throttle Body Balance The Cheapskate Way

Disclaimer: this is not meant to be a full tutorial for someone with no mechanical knowledge.   If the following makes no sense you might want to have someone else do it:)

So there are lots of carb/throttle body balance tools you can buy but for about 2 bucks and 5 mins you can build your own.

Just get a length of standard fish tank air line tubing (I just paid $3 for 12 feet) and something about 3 feet long to tape it to.

Take the tubing and tape it to the whatever making a u shape where the tubing goes down one side,  makes a 180 at the bottom and comes back up the other side.

Put some liquid in the tube (I've always used atf I dont recommend water for hopefully obvious reasons) so that it settles somewhere around the middle of both sides of the u in the tubing.

Warm up the bike so she's at operating temp.

Connect each end of the tubing to one side of the throttle body after disconnecting the lines that go to the Evap Crap.

Now give the bike a quick start.   Be prepared to shut it down if one side starts pulling the atf in really quickly.   Unless someone's been messing with the air screws it should already be close to balanced so this shouldn't happen.

Ones she's running watch the levels and if one side is creeping up turn one of the air screws a tiny bit (it's pretty sensitive.)  If it creeps more turn the other way.

After each adjustment crack the throttle.   If one side of the tube creeps up too far just shut the bike off and let them relevel.

Got em holding steady?   Great now adjust your idle to around 1300rpm. Recheck,  crack throttle Yada Yada.

The nice thing about this type of gauge (called a manometer)  is unless there's a leak in it it cannot be inaccurate.   If the levels arent moving the throttle bodies are balanced.

The FSM has good info on this procedure.   If you don't have it let me know I'll send it to you.  

Hopefully this helps someone who wants to check this.   The balance can drift over time and if they aren't balanced the engine will run rougher than it needs to.

I use a similar method but prefer to use a couple of plastic bottles instead of the loop of tubing. I tried the tubing method some time ago but changed over to using bottles mainly because the levels change quite a bit slower and smoother than with tubing and it's easier to see when the level is even due to less fluctuation. Here's a link a uTube set up much like mine. This setup can work with any number of cylinders, just add a bottle for each carb or throttle body.
https://video.search.yahoo.com/yhs/search?fr=yhs-avg-fh_lsonsw&hsimp=yhs-fh_lsonsw&hspart=avg&p=home+made+manometer+for+cab+balance#id=1&vid=e9347619df3dd098602c849745695abb&action=view

Yeah the bottle setup is definitely superior but the single tube has always served me well. Of course the tube method only works for a 2 cylinder so if someone has more the bottle setup is pretty much the only option.

Kenny,
I made a manometer using two glass bottles. See pic. The good thing using the two bottle method is that you cannot screw anything up like sucking the meter fluid into your engine. It is very simple to use. 

Details for novice:
Just connect each of the five foot hose to each fuel meter vacuum connector. If your vacuum is way off, the fluid would flow from one bottle into the other one. The higher vacuum side will cause the metering fluid to rise. Use the vacuum adjustment screws the lower the vacuum pressure. Always checking your idle RPM.

That's a good lookin manometer and yeah it is nice to not be able to hydro lock your engine:)

I just use my old Morgan carb tune that I've had for donkey's years. I only checked it once, found out that it was as near perfectly balanced as to make no difference, re-assembled and left alone. Pud.

Yeah mine was pretty close, even with having swapped engines (I reused the original tbs)