BB carb synchStart to finish

OK, this I understand. I can't quite picture the common vacuum rail but I'm sure I can find it when I look tonight.

Then after the carbs are in sync you adjust the idle mixture using the colortune (or ear), check timing and recheck sync. Correct?

I guess I'm not fully understanding why all the idle air bleeds would be out and in need of adjustment?

Drew,
A couple of points worth mentioning...
The procedure I wrote is based on staring from a totally unknown baseline...

If your engine is running reasonably well, you might not want to screw the air bleeds all the way in. Rather, just verify the airflow prior to any adjustments. The "trick" to get the airflow accurate through all barrels is to do the check at the lowest possible idle speed. Once the throtte plates start to open, the volume of air going through the air bleeds becomes inconsequental as compared to the primary air going through the main barrel.

Correct...After the initial synch has been done, the mixtures are set. Colortune, ear?, accurate tachometer, lean drop method...or exhaus gas analyzer all work to set the mixture...Some methods are better than others...and past performance is no indication of future results.

The common rail, as I call it...looks like a piece of brake line, that connects all the intake manifolds on one side together, and then with a small piece of vacuum line, connects to the alu tube near the front of the valve cover breather hose. If you remove the "L" shaped hose from the VC to the breather, you'll see the "end" of the common rail and where it connects to the alu breather pipe. This is the point where I hook up my vacuum gauge(s). If you don't have two high-precision gauges, you can check airflow using your manometer, though you may need to adjust its restriction orifice to get a decent reading.

When all is said and done...I go back and recheck everything. This method may not be the best way, so I'd be curious on the JRV comments.

Best of luck!

JRV,
Good point...
My procedure was based on starting from zero...
In the previous post to Drew, I make reference to that point.

David

The reason I asked , the less screws the novice touches the better the outcome will be imo {} (no offense to novices everywhere). And since the carbs are working, I was bypassing alot of potential room for miscalculation by going right to checking existing balance carb to carb and side to side conformity.

Anyway, I don't have the proper amount of time to analyze all this data and procedures at the moment, but it would be great to have this entire procedure in the permanent archives below to help future visitors and to distiguish the differences from Daytona setting & Boxer setting.

Regards, JRV

Couldn't agree more...The more screwing you do, the more likely you'll get screwed doing the carb set-up.

JRV...I do realize that the procedure I wrote is a bit lengthy, but when you have a chance, please review it...and we'll develop the finalized version for the tech archives. I'm not 100% that my procedure is the most efficient or most accurate, though it does seem to work for me.

I saved the orginal text in a MS Word document, so edit are easy....

Onward,
David

Thanks guys for all the information.

I understand. It's interesting that you balance the entire left side then move to the right side whereas JRV balances the primary carb on the left to the primary carb on the right. I can see how either works.

I'm going to give this a try when the manometer and colortune come in. However the first thing this novice is going to do is keep records of all the initial settings.

Drew

Drew & David,

I think this may be the difference in techniques.

In my procedure I'm already anticipating an idle rpm rise and try to mitigate to the minimum while still getting balance, and going in, I want to keep the amount of time the engine idles with unknown mixture settings (anticipating rich) to a bare minimum to avoid plug fouling before I can get to the mixture portion of the drill. So I try to quickly achieve air flow balance per control throat, in order to jump to mixture setting/checking....also my personal shortcuts start out assuming there are no especially difficult problems to deal with.

There is no quick and easy way to go thru this entire procedure and the danger I try to avoid is prolonged idleing which heats up the intake ports and skews the setting and especially fouling a plug by one or more perhaps overly rich cylinders.

Think about this and give some feedback.

JRV,
I've given considerable thought to the differences between your method of carb adjustment versus mine...and spent a few moments really looking at the linkage set-up. To be quite candid, despite the years of doing it "my way", I like an aspect of your methodology better. It does makes more sense, in the interest of getting the carbs in close synch fast, to adjust side to side (hard linkage) first....then bring the linked carbs into snych.

A very clean approach, if I don't mind saying so!
I really appreciate your input here...

If you don't mind, I'd like to edit my procedure, reflecting your suggestions...and post it in the tech archives.

Regards,
David

David,

sure, you realized of course that my shortcut certianly does't circumvent your correct lenghthy procedure, it simply anticipates a few results in advance, and once the first go round is close then one must fall back to "dialing in", by means of the full procedure you posted.

So by all means feel free to piece together all the input so far to produce a perhaps streamlined set of guidelines to help others in the future and add to the permanent tech archives.

Regards, JRV