Topic: Bench Sync 550, HELP PLEASE

[fletcha221]

Did a search and didn't find anything. What is the proper drill bit size to bench sync a set of cb550 carbs? I am running 100 jets, stock airbox, exhaust, etc. I have the carbs off for a cleaning, I figured I should get them all running together. Thanks guys!

[jessezm]

People recommend a 1/8" bit for any set of carbs.  Once you get them close to each other, you can get the idle adjusted to the right point with the idle speed screw before moving on to your actual synchronization.  The bench sync won't really be sufficient on its own.

[KeithB]

The "bench sync" will only get the sliders to be, roughly, working at the same time. Gives you a good place to start to get the engine running. I have had some pretty good results with this method but a proper vacuum sych is best.
It's not the size of the drill that matters.
Adjust the idle screw to open the sliders some and use the drill bit like a feeler gauge to get the same opening on each carb.
Don't forget to re set the idle screw before starting.

[traveler]

If you have PD carbs, the #2 (from the left side sitting on the bike) is fixed, and all carbs must match it.

you can use a drill bit, but again, match everything to the fixed adjusted carb.

If an earlier carb setup where all carbs are adjustable, set the #4 carb next to the idle adjustment with a 1/8 drill bit, and then match the others to it.

Lastly, do a search on here.  LOTS of talk reference this situation.....that's how I figured it all out!

Good luck!

~Joe

[fletcha221]

Cool! Well, I used a bigger drill bit on my 350 the first time, and the idle was around 3 grand......thats why I was asking. I thank you all for the advice!

Now......If I could just get these freagin emulsafier (sp) tubes out.....Got one, and it was perfect, the others, not so much. Let carb cleaner sit in there, then blasted all the passages with my air compressor......we should be in business when the new jets get here.

Thanks again!

[traveler]

I am merely passing on knowedge I weaned from the elders on here and using the search function read YEARS of posts on it.  In the FAQ section, at the top is a thread called "carb FAQ".

Do yourself a favor, grab a cup of coffee, and read the whole thing.

Since I see your bike is a 1975, you don't have PD carbs.....so, unfortunately, your gonna have to do some research.

~Joe

[faux fiddy]

Did a search and didn't find anything. What is the proper drill bit size to bench sync a set of cb550 carbs? I am running 100 jets, stock airbox, exhaust, etc. I have the carbs off for a cleaning, I figured I should get them all running together. Thanks guys!

1/8  is what my closest guru said. Here's last weeks threads.

http://forums.sohc4.net/index.php?topic=73128.0

Emulsifyer removal- ball point pen with the cover on, approaching from the tops, use it to push them out, tip 'em over and tap tap the end.