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Carb Sync tool needed in Austin

Kilroy

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Joined
Apr 25, 2007
Messages
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Location
Austin, TX
Hey folks,

After the rebuild and bench sync on the 74 CB350F, it starts! Now I need to proper sync it, and I don't have the gauges to do that. Anyone got one I could borrow in the Austin area for a sixer? Or better yet, to help me so I don't screw it up?
 
Kilroy,

I have a 4 port carbtune you can borrow (say 2 weeks?). Its easy to do. I use to sync carbs with a garden hose so having a tool makes it a piece of cake.

- start bike and run it up to temp and make sure it has a low idle
- now turn engine off
- crack all the carbs loose from each other
- hook guage to each carb ( vacuum port )
- start bike and leave it at idle ... I mean leave it idle!
- adjust each carb to pull same amount
- turn off engine
- disconnect guages, replace vacuum caps on carbs
- reconnect carbs to each other
- start bike and adjust idle
- done

Shoot me an email if interested.
 
You can also use the idle drop method if you do not have access to a sync tool

If the bike is running reasonably, start from the current settings, if not then
do the following for each carb - screw the mixture screw in until it lightly
bottoms out - counting the number of turns. Record the number of turns so
you can always set the mixture back there if needed for any reason. Now
back the screw out the recommended number of turns for your bike - it is 2
3/4 turns for mine.

* run bike to get it to normal operating temp and ensure the chokes are all
off (closed)
* adjust idle as low as possible and still maintain a steady idle (rpms
steady). A sensitive tach or practiced ear are needed to detect rpm
changes. The bike tach is not sensitive enough. A slow idle makes the
drop off point more noticeable.

Do the following for each carb, one carb at a time, adjust the idle if needed
between doing each carb and wait if the fan comes on as it will affect idle
speed:

* adjust mixture screw in (LEANER) until the rpms start to drop.
* adjust mixture screw out (RICHER) until the rpms start to drop - counting
the number of turns. Expect to go several turns.
* set the mixture screw at the mid-way point between the two points
(optimum) by turning it in half the number of turns.
 
He is trying to balance the carbs. Not sure why you would touch mixture. Depending on the carb, the mixture screw your describing is just the pilot jet; i.e. idle circuit. Don't see how this has much to do with balancing the carbs. But I don't know the carbs on this bike. I just know that when balancing, your trying to suck the same amount of air through each carb and for that you use a carb sync tool or simpler measures (hose) if you don't have a tool. I bought my carbtune back when I had a 6cyl Valkyrie.
 
Sorry y'all, I forgot to turn on notifications for this post. A buddy in town got one to me, and I found out my #3 was drastically low.
 
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