Bench sync'ing carbs

[tkent02]

Come on guys... Can't you see that it was meant as light humor?

My point was simply that a bench sync is just a short term thing to get the bike started. Weather you use a pin, a flow bench or your eyes is irrelevant. All you're really trying to achieve is a "close enough" sync so you can do the proper sync for your engine's condition using a proper tool. It's not rocket science at that level. I use a thin feeler gauge and that seems to work for me.

Now if you want to go into great detail, then discussing methods to get your final sync would seem more productive. That's where things get more critical. Lots of potential science there to entertain the mind as well.

+1, Absolutely correct on all points.

[mvalenti]

True, but getting them at least CLOSE to the same is what does it.

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I have a method that involves chanting, an alter, and chicken blood....

[Old guy]

It's just a simple manometer arrangement. I shot a short video but haven't uploaded it.

The vacuum cleaner will pull so many inches of water up a tube when deadheaded. Any leak will reduce vacuum, i.e. Throttle opening, and the water won't come up as high.

Adjusting the blades to pull the same amount of water up the tube, "syncs" them.

So it's just a loop of tube running up high enough to keep from sucking all the way up. One end in a cup of water, the middle up, other end fitted to the vacuum cleaner hose.

It not "rocket surgery"

[JTGS850GL]

It's just a simple manometer arrangement. I shot a short video but haven't uploaded it.

The vacuum cleaner will pull so many inches of water up a tube when deadheaded. Any leak will reduce vacuum, i.e. Throttle opening, and the water won't come up as high.

Adjusting the blades to pull the same amount of water up the tube, "syncs" them.

So it's just a loop of tube running up high enough to keep from sucking all the way up. One end in a cup of water, the middle up, other end fitted to the vacuum cleaner hose.

It not "rocket surgery"

Hummmmm???? Seems like a feeler gauge or a set of eyeballs would be a lot easier.

[850GT_Rider]

Adjusting the blades to pull the same amount of water up the tube, "syncs" them.

....which is exactly the same thing you'll be doing again, on a running engine - the very engine you'll actually be using the carbs on. Why do it twice?

Eyeball, drill bit, feeler gauge, whatever, is good enough for the bench. Slap 'em on, crank it up, and balance them using a quality manometer (aka carb guage).

Done

[Steve]

Now if you want to go into great detail, then discussing methods to get your final sync would seem more productive.

Don't worry, that project is in the works, too.

.

[Old guy]

Video of rocket surgery

http://youtu.be/wfa9PJIdBR0

[Nessism]

Come on guys... Can't you see that it was meant as light humor?

My point was simply that a bench sync is just a short term thing to get the bike started. Weather you use a pin, a flow bench or your eyes is irrelevant. All you're really trying to achieve is a "close enough" sync so you can do the proper sync for your engine's condition using a proper tool. It's not rocket science at that level. I use a thin feeler gauge and that seems to work for me.

Now if you want to go into great detail, then discussing methods to get your final sync would seem more productive. That's where things get more critical. Lots of potential science there to entertain the mind as well.

I agree. I don't even bother to bench sync most of the time. Go straight to vacuum sync.

[posplayr]

Video of rocket surgery

http://youtu.be/wfa9PJIdBR0

Thanks for the video. It looks pretty easy once you get everything setup. It is also probably much easier to set the throttle settings with the crabs off the bike.

Please report back how much adjustment is required after install.

[Steve]

Video of rocket surgery

http://youtu.be/wfa9PJIdBR0

I know the term has always been "bench" sync.

THAT took up half of the garage.

(and I had to turn my computer sideways to see it)

.

[tkent02]

If it took longer that the minute or two it takes to eyeball them, it's a waste of time and effort.

[posplayr]

If it took longer that the minute or two it takes to eyeball them, it's a waste of time and effort.

Like he said rocket science.

[GSX1000E]

I LOVE the thinking outside of the box to home brew a system to mimic a running engine with so few household items. Genius!

[nejeff]

Probably takes longer to plug in the shop vac then it does to do a bench sync.

I appreciate the ingenuity on some level but aren't you just going to vac sync once they are on the bike anyway? Your solving a problem where there isn't one

[Steve]

I appreciate the ingenuity on some level but aren't you just going to vac sync once they are on the bike anyway?

The vacuum sync should be good until you have to adjust some valves.

Changing valve clearances will change how much that cylinder can breathe, which will change the amount of vacuum it produces, because it still has the same restriction (the throttle blade).

Yep, you will need to do it more than once, unless you sell the bike, but you will need to do a sync on the next bike.

.