Topic: Pilot Screw

[kokomolock]

Hello all!!!  I have a 1976 CB750A with 18,000 miles on her.  I just purchased it last year and I am working on getting it running right. I have installed a new air filter, plugs, plug boots, oil change, and cleaned the carbs.  I have the service manual and have checked the points, checked the valve gaps, set the cam chain tension.  I also bought a set of carb sync gauges and ready too use them.  I am trying to set the pilot screws according to the service manual and no matter how much I turn the screws the RPM's don't change.  I am new at motorcycle work but not with engines.  Am I missing something?  Thanks in advance for any help. I live in Indiana and if anyone can help and wants to borrow the gauges let me know.  The link is the gauges I bought.  Thanks again.



http://www.ebay.com/itm/Vacuum-Carburetor-Synchronizer-carb-sync-Gauge-Yamaha-XS-XJ-1100-1200-pro-/380893178949?hash=item58af00ac45&item=380893178949&pt=Motors_Automotive_Tools&vxp=mtr

[bjbuchanan]

The pilot screws shouldn't radically change the idle, they don't adjust your idle. The main adjustment knob (the big one) on the carb rack is what adjusts it.

If you have no effect from them at all it could be dirty carbs. Set them to 1 turn out and leave them unless you want to do fine tuning. 1 turn will be close enough to do any other work like syncs

[raymond10078]

My experience is similar - that the mixture screws only changed the idle slightly.  It wasn't at all like adjusting a V-8 carb where the engine speed change is quite noticeable.