Idle speed is too high. Adjustment bolt doesn't work.

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Fire-medic

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Spray some starting fluid around all the joints for the intakes, you'll find the leaks.
 

02GF74

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How fast is it? How are you measuring it? Do you trust the rev counter?

From memory idle should be 1,100 rpm off choke.

Are the enrichment pistons fully in when choke is off?

Also check the carb balance screws are not at their limits.

Check there is slack in the throttle cable, if the cable end is not fully seated at the carbs, it may well be pulling on the butterflies.
 

DreamV4

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How fast is it? How are you measuring it? Do you trust the rev counter?

From memory idle should be 1,100 rpm off choke.

Are the enrichment pistons fully in when choke is off?

Also check the carb balance screws are not at their limits.

Check there is slack in the throttle cable, if the cable end is not fully seated at the carbs, it may well be pulling on the butterflies.
Rpm is about 3000 or so. Tacho doesn't work. Cables are disconnected(plastic joint box is removed.).
 

Fire-medic

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Are your synchronization screws' springs coil-bound?

I think your results with your rack will be better with a functional throttle, and a good synchronization.

In light of your reversed front ignition coils' leads, be sure that you attach the push/pull throttle cables correctly.

Read this thread, digest the info, and utilize your new-found knowledge, skills, and abilities to implement the data therein.

(76) Can't sync the carbs... | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net)

Ten pages, that's a lot of information to assimilate, and to implement. I believe your answer lies in there. You've shouldered a considerable burden in this 'project bike.' With your innate ability to sort things through, with members' help, I have faith in your vision-quest.

Vision Quest.png
 
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DreamV4

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I was turning synchro bolt instead of idle adjustment bolt... 😭
Getting smarter every day!!!:)
I watched my own youtube video about bench synchronizing to recall how to adjust again... Well, I need to synchronize installed carbs anyway...
 

02GF74

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I was turning synchro bolt instead of idle adjustment bolt... 😭
This shows exactly why it is so difficult to diagnose problems remotely.

Anybody seeing what you were doing would have immediately noticed that you were not turning the idle adjustment knob whereas from your description it sounded like you were.

You are becoming so smart, be careful your brain does not explode with the newly acquired knowledge.
 

DreamV4

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You are becoming so smart, be careful your brain does not explode with the newly acquired knowledge.
After buying about 40 dead bikes and dealing with almost every possible bike problem, my brain is close to its limit...:rolleyes:
 

Fire-medic

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There's a reason I keep posting a link to the factory service manual when I post a response to someone's operational/maintenance/repair question. If in-doubt, haul it out (the service manual).
 

02GF74

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After buying about 40 dead bikes and dealing with almost every possible bike problem, my brain is close to its limit...:rolleyes:
Your brain may already be full as on every multi-cylinder bike I have owned and not owned (have just the carbs),* the idle was set specifically by a knob on the end of a screw.

Car carbs (weber, SU) would have just a screw.

As for reading the manual, come on!!! Most of us on here are male and that means we don't read manuals, don't multi-task, eat beans straight out of the tin nor ask for directions.

*the number is 5
 

DreamV4

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Picture of idle speed screw was unclear in manual (or it is just my lame excuse). I used idle speed screw when bench synchronized my carbs a few days earlier. Getting old? 😭
 

DreamV4

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Idle speed screw bracket was bent, impossible problem!!! Very high tech diagnosing!!! :)
 

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