Bench sync...... Using a vacuum cleaner

It works just great until you forget or get lazy and leave some fuel in the float bowls... but that would be okay if your name was Wile E Coyote! Remember gas fumes are way more combustible then liquid and vacuum motors have brushes that spark when the motor runs!!!! :eek:
 
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Are the carbs back on the bike? Would love to know how well synched they are from this method, when you get them back on.
 
Bootsey said:
Are the carbs back on the bike? Would love to know how well synched they are from this method, when you get them back on.
Obviously, this was staged because gas explodes in a vacuum just like in space.
 
It's not a substitution for an actual sync on a running motor. I'd venture to say, it's another option, and maybe better than a feeler guage or eyeballing it.

I'll check it at some point. Valves are in spec, carbs are clean, main jet is too small. It idles great. low throttle steady state hunt and surging is gone, but it's lean up top. Main jets will be here tomorrow.

I'd venture to say, it's closer than bench syncing with a feeler guage or eyeballing it. As well as it's doing right now sync is lower on the list than getting WFO throttle working right first.
 
I thought it was pretty clever, in a Rube Goldberg kind of way.
 
Curious to see if it'll pick up variances between jets. Testing the jets out of the carbs. But, I'm pretty sure the vacuum cleaner won't pull enough. Not for flow but consistency. If it will, you can put the richer jets in the middle cylinders (to keep them cooler).
 
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