Throttle body sync w/ "choke" on?

[F14CRAZY]

So as others have used I've put together some clear tubing with some ATF which I hook up to the vacuum ports on my K75's throttle bodies to sync. And at idle the ATF pulses and going by the advice I've read I adjust the throttle bodies so they pulse equally, or something close to that.

Of course I gave the bike some throttle and observed that the pulsing stops and the oil level stabilizes.

I haven't tried it yet but got thinking...what if I used the fuel enricher ("choke") to raise the idle RPM in an effort to stabilize the oil levels in my sync device? The throttles wouldn't open more and airflow would just be through the idle ports so I don't see it throwing off the reading as far as that goes.

Would it work? Thanks guys.

[The Mighty Gryphon]

I don't think it will work.  The "choke" is actually an idle speed adjustment that opens the butterflies very slightly.  That is going to bypass the idle air screw on the throttle body and throw off the idle vacuum that you're trying to read. 

The proper way to stop the pulsing is to put an orifice in each vacuum line.

[F14CRAZY]

I don't think it will work.  The "choke" is actually an idle speed adjustment that opens the butterflies very slightly.  That is going to bypass the idle air screw on the throttle body and throw off the idle vacuum that you're trying to read. 

The proper way to stop the pulsing is to put an orifice in each vacuum line.

aw crap. I always thought the "choke" just had the injectors squirt a little more fuel and make the system run a bit rich. I agree that opening the butterflies would throw things off.

Where do you obtain a vacuum orifice?

[K1300S]

The choke is just a fast idle. Opens the butterflies.

Orifice is just a block in line with tiny hole.

My recommendation is to ditch the mcgyver oil rig and get a Carb Tune.  Far more accurate and easier to use.

[rbm]

Pet supply store selling fish tank supplies.  You should be able to find adjustable valves that can be plumbed into the vacuum lines between the gauges and the injector bodies.   Once fitted, you'll have the means to damp them down and stabilize the fluid columns so you can read them.  Alternative is pinhole-sized flow restrictors in each vacuum hose to minimize the bounce.  Take some round stock (wood or plastic) 1/2" long and that fits tightly in the ID on the tubing.  Drill a #60 hole through it, and jam it in the middle of the tube.  Easiest is to slice through the tube part way up and use it as a joiner.

[TX brick]

A two bottle manometer is also easy to use and requires no restrictors.

[The Mighty Gryphon]

Here's mine.  Too bad the system won't let me attach the photo.  It's pretty nice.

[jay1622]

Sounds like lots of work guys... I'm sitting on a twin-max, so admittedly, I'm a little spoiled, but I was wondering... Why not just use a couple of vacuum gauges with equal length tubing? Just wondering.

Not these exactly, but the idea can be pieced together at Lowe's for equally less perhaps.

http://www.amazon.com/Emgo-Carburetor-Synchronizer-84-68594/dp/B003CJGDE8/ref=sr_1_10?ie=UTF8&qid=1456071317&sr=8-10&keywords=Vacuum+Carburetor

[F14CRAZY]

Would vacuum gauges not pulse?

[jay1622]

They would (should) respond much the same way as my twin-max does at its most sensitive setting. At idle, the needles are all over the place. At a decent engine speed, however, things typically smooth out.

[rbm]

Like the liquid gauge, mechanical vacuum gauges will fluctuate too wildly at idle, unless restrictors are used.  They are probably less sensitive and less accurate compared to liquid.  A profession gauge like Carbtune Pro is best, next best is the manometer based on bottles, after that is twin-tube manometer, and finally mechanical gauges if comparing sensitivity, precision and ease of use.

[K1300S]

the carbtune comes with the restrictors.  readings are stable at idle speeds....

[The Mighty Gryphon]

I like my two bottle manometer.  Cost me under $15 and I got to drink two bottles of Snapple.

Remind me, how much does the Carb Tune thingy go for?

[K1300S]

$120.  Worth every penny to me.