Can't sync the carbs...

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Zenuwlijer

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What the hell is happening? My carbs have been rebuild and synced by a mechanic, but I wasn't really satisfied how it ran.

So I pulled out the Carbtune and had a look.

(See the video in the first post.)
 

Zenuwlijer

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After seeing the odd results, I figured I'd just sync 1-2 with 3-4, using the front sync screw on the right hand side.

No such luck. Tried to play with the idle speed, but couldn't get it to work.
 

dannymax

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The front sync screw on the right hand side (#4) syncs #3 & #4 to the left side carbs.

sync procedure:
-2 is the master carb, everything is sync'd to it
-sync 1 to 2 using the sync screw on 1
-sync 3 to 4 using the sync screw on 3
-sync 3-4 to 1-2 using the sync screw on 4
 

VMAXXIMUM

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A little off-topic but related. I find that the sync screws are super sensitive just touching with the screwdriver changes it. I’ve also noticed that the sync changes pretty easily. Is there a way to tighten up the screws, like adding a washer or something on the threads?
 

Parminio

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A little off-topic but related. I find that the sync screws are super sensitive just touching with the screwdriver changes it. I’ve also noticed that the sync changes pretty easily. Is there a way to tighten up the screws, like adding a washer or something on the threads?
Never seen that or even heard of it.

As you make an adjustment you're supposed to blip the throttle a couple times to get the linkage to settle and then see where you are. If you are doing that and it's still that sensitive then you've got something wrong. A missing return spring, a missing screw spring, something.
 

Zenuwlijer

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The front sync screw on the right hand side (#4) syncs #3 & #4 to the left side carbs.

sync procedure:
-2 is the master carb, everything is sync'd to it
-sync 1 to 2 using the sync screw on 1
-sync 3 to 4 using the sync screw on 3
-sync 3-4 to 1-2 using the sync screw on 4

Yup. Followed that exact procedure as per the Haynes manual and this forum. Also the right cylinder / carb numbers.

16266110366115673121651010903739.jpg
 

Parminio

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According to your sync gauge you just need to adjust the front screw on the right side of the bike to make your 3-4 match your 1-2. Should take you all of 45 seconds.
 

Parminio

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If you're all the way out go back in. If you're all the way in go back out. It's that screw that's the problem. If nothing changes as you turn that screw then you have a problem like a missing spring or broken linkage or something.
 

dannymax

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You may have to tip them upside down and see why that is happening. Some tabs may need 'reformed to adjust'?
It's generally the #3 that needs that however.

* I'd set aside bit more than 45 seconds for this. lol
 

Zenuwlijer

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If you're all the way out go back in. If you're all the way in go back out. It's that screw that's the problem. If nothing changes as you turn that screw then you have a problem like a missing spring or broken linkage or something.

Nothing changes indeed.

I found another thread about this problem a little earlier, when I was still messing around with it. After reading it, I was very frustrated and put the bike in the garage.

 

Parminio

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That picture is awfully dark. I went out and took a picture of mine. I want you to check yours against mine. See that red circle? See how I have the tension spring wrapping over both the left and right edges of the bracket on either side of the screw?

(You may need to download the image or open it in a new browser to increase size to see it clearly.)

Make sure your screw has those spring ends lapping over it.

Vmax spring over screw.jpg
 

Parminio

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The right front screw needs to be backed out, not screwed in...according to your gauge
Not the point I was making. If it was all the way out already, which is what he suggested, I just wanted him to turn it all the way in to see if any change at all took place.
 

Zenuwlijer

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* I'd set aside bit more than 45 seconds for this. lol

I was sitting next to the bike for over an hour this morning. 😭

And the most "funny" part is... I paid the garage 622 dollar to fix and set my carbs.

(All four carb diaphragms were punctured.)

And now... I'm still f#cked.

I cannot prove he did anything wrong.
 

Zenuwlijer

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That picture is awfully dark. I went out and took a picture of mine. I want you to check yours against mine. See that red circle? See how I have the tension spring wrapping over both edges of it?

(You may need to download the image or open it in a new browser to increase size to see it clearly.)

Make sure your screw has those spring ends lapping over it.

View attachment 78319
I will roll the bike out to the driveway.
 

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