Carb Balancing by "highest idle" instructions?

[Guest]

I've reinstalled my carbs after giving them a good cleaning and would like to synch them up. I don't have a CarbTune or a similar device so I guess I need to synch the barbs by the Highest Idle technique. I've read in other threads about setting them by the Highest Idle but I haven't been able to find specific instructions for that technique.

Can someone provide me a link, or paste the instructions? I searched GSR, I swear!

Thanks!!!

Kevin

[TheCafeKid]

There's no syncing the carbs by highest idle. You set the mix screws with the highest idle method. You need to bench sync, and you will need manometer to dynamic or vacuum sync.

[Steve]

True enough. You need to to a bench sync, which is just checking visually that the carbs are open about the same amount at idle speed, then do a dynamic sync using gauges. THEN you can check the idle mixture screws by using the highest idle method.

Here is what you are looking for on the bench sync. Notice the openings under the throttle butterflies.
Adjust the sync screws between the carbs so the sliver of light is as close as you can get from one carb to the others.



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[LoopGaroo]

Ok, I got my stuff mixed up...Still learning the lingo I guess.

I already bench synced. But I would still like to know how to set the mix screws by the highest idle.

[cowboyup3371]

Look on Basscliff's site for the highest RPM article for the mixture screws.

[LoopGaroo]

Hey - Thanks a lot!

I can't believe I missed that on Basscliff's site. That's my first stop for GS knowledge.

So, CafeKid & Steve, you guys think that doing a vacuum sync is an absolute necessary step? I'm just balking at buying the tool...

[Steve]

So, CafeKid & Steve, you guys think that doing a vacuum sync is an absolute necessary step? I'm just balking at buying the tool...

Let's just put it this way, ... "do you want a smooth-running bike that is a pleasure to ride?"

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[keman]

There may be folks local to you who have the tool.. . Put an add on craigslist.. . Maybe safe you a few bucks. Carb sync is required for your bike to run well. Absolutely, required.

[Steve]

I know there are several members out in the western and southwestern 'burbs, as well as northwest Indiana. May contact them?

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[LoopGaroo]

Yea, there's also a weekly "Garage Night" put on by ChiVinMoto, a local motorcycle forum. Once it warms up I'll be able to ride over to one of these gatherings and get a little help.

Any recommendations on a user-friendly sync tool? I might be able to justify it.

Can these do the job?

It's half the price of a Morgan Carbtune.

[Steve]

Can these do the job?

It's half the price of a Morgan Carbtune.

Yes, they can "do the job", but be warned:

Half the price and more than twice the frustration.

The only good part of that set is the brass adapters.

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[TheCafeKid]

I've never used those but I've heard a lot of complaints about them as the needles jump about pretty bad.

As for it being absolutely necessary... Well I agree with Steve. I'm also a bit psychotic at times about how my bikes run. However, I will say I've gotten lucky a time or two with a careful and patient bench sync and the bike ran well enough that even I didn't freak out about a dynamic sync until I had someone who is much faster at it than I to do it. I can do it, it just takes me so long sometimes I worry about cooking the head...

[Big T]

Can these do the job?

It's half the price of a Morgan Carbtune.

Maybe, if you want to spend that much time

Those cheap guage are not accurate, so you have to use a standard pressure to zero them individually very time you use them. Plus, as stated, they junp around a lot.

Watch for Joe's annual tire changing party. I'm sure he has the tools and the knowledge to teach you what to do. It's not like you need to sync the carbs very often

[LoopGaroo]

I went ahead and ordered the Morgan Carbtune. I share a garage with a fellow who rides a '81 CB750, so I figure we'll use it enough.. he'll owe me a couple beers i guess

[hampshirehog]

Those cheap sets are fine - the needles only jump around if they're not damped. We used to use the Kawasaki sets rather than the Suzuki gauges as they were easier and the Kwacker set were dial type, almost the same as those cheap ones.

You can pay a lot more and get the Davida dial type gauges as well. They work, just no better than the cheap set - if you damp things down.