Topic: CB750K2 I just did my first carburetor sync

[jeremyillingworth]

After putting it off for a while I finally got around to my carburetor sync. I got a Carb Tune and it was rather easy to set up. I put a fan on the bike but it was a very hot day, approaching 30 degrees.

I didn't want it to drag, since the bike is just idling and getting hotter but I also wanted to be patient and do it right.

I was surprised how often I needed to adjust the idle. I quickly lost the notion that it would be all perfect and all the carburetors would show the exact same reading.



I think I did a pretty good job. I found it hard to work when the idle was too low; most of my readings were taken around 22. I should have timed myself but didn't. When I was done the bike was hot. I could touch the engine but not hold my hand on it. After I shut it down I kept the fan going and after a while pushed it into the driveway and (hope this wasn't a bad idea) cooled it down with some water.

After cooling longer I fired it up and now I see what people mean by 'sewing machine sound'. A quick, three mile test run and all seemed well.

How long does it normally take you to sync up?

How long is safe to run the bike with a fan on it?

Do you just work one at a time or loosen them all at once?

Does anybody actually torque the 10mm nuts down when finished? I was going to but I found out my torque wrench doesn't go that low. I snugged them up.

jeremy

[seanbarney41]

sounds like you did fine, except there was no need to cool down with water and I hope you didn't warp anything.  The bike should be just fine idling all day with a good fan blowing.

[flybox1]

Sync looks good.  Nice job.  Typically takes me 5-7 minutes or so once all set up with the tubes, fan aux tank, etc.  Adjust, blip, idle, repeat....
And yes, a fan is all you need.

[jeremyillingworth]

I definitely wasn't that fast, probably at least double. I'll get an opportunity to practice every 3000 miles.

jeremy

[seanbarney41]

I definitely wasn't that fast, probably at least double. I'll get an opportunity to practice every 3000 miles.

jeremy

not usually necessary to do it that often...although it does get easier with practice