So I’m finally getting around to starting my R75/7 and syncing the carbs. I have a Bing book which says to sync the cable lengths first, then the idle speed and finally the idle mixture. I have also read snowbums method and he states that the cables should be done last. Is there a preference and is one method any betters than the other!
>> The preference is to get the job done quickly and efficiently.
>> Like Snowbum, I prefer to start at the bottom (lowest speed) and work up. I like this method because if the idle (speed & mixture) is set first, then you definitely know how much slack to leave in the cables. Working the reverse method from high to low means you might need to go back and do the cables again, if the idle setting reveals insufficient slack in the cables.
>> For reference, my method is something like...
* Ride the bike until fully warm
* Return to the shop, ignition OFF, and put a box (window) fan on the engine
* Connect your carb vacuum sensor
* Set both Idle Mixture screws to 1.5 turns out
* Start the engine
* Even out the L&R vacuum readings at ~900 RPM using the Idle Speed screws
* Tighten the "cruise control" thumbscrew for the twist grip. (This part may need to be added.)
* Set the RPM for ~1700/1800 RPM
* Use the cable adjusters to even out the L&R vacuum readings
* Stop the engine. Check for 1 to 2mm of cable housing slack at the twist grip.
* Loosen the "cruise control" thumbscrew. Remove the vacuum sensor. Lube the throttle cables.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Agree, balance the cables last. I start with idle mixture and idle speed screws because all of that is done with the cables slack. Be sure they are slack so the throttle butterfly stop is truly resting on the idle speed adjustment screw (with spring tension). Once the idle speed and balance is good, pull the throttle like Richard said to 1800 or so, and balance the cables. A throttle lock is sure handy here. I find that balancing the cables can be fiddly. Very sensitive operation.
Thanks for the replies. Funny that Bing says the opposite but what you all say makes sense to me.
I like my Harmonizer!
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