RG500 Carb Sync

   

   

Slacken all 4 Throttle Cables

That means make them loose.  When the twist grip is used to pull on the main throttle cable a little bit the carb slides do NOT move.

 

 

   

Adjust Throttle Cable Free Play

 

 

Adjust the cable slack at the grip to have a 1-2mm of play only.

 

Wrap a bungee cord or some 1/8” vinyl hose (or clothes line, or 12ga wire, etc.) 1.5

times around the throttle between the stock grip and the housing to act as a friction

brake to hold the throttle stationary while synchronizing the carbs.

 

It is Very Important to adjust the right side first.

 

Use a flashlight to properly illuminate the dot and throttle bore to dispel shadows

 

The left side adjusters typically ride 3 turns higher than the right side. It's just how the

cables are cut.

 

 

 

 

Adjust Oil Pump Cable.

 

Screw all 4 Idle Air Screws all the way in.

 

Set all 4 Idle Air Screws to 1 ½ turn out.

 

 

 

Start engine.

Feel all exhaust pulses & adjust Throttle Stop Screws until each cylinder is working as hard as all the others, while adjusting the Throttle Stop Screws as necessary to obtain good idle.

 

 

Perform Final Idle Air Screw adjustment:

a.      Ride bike on straight flat level surface at idle with throttle completely     shut.  Idle along on the carbs only; Throttle Cable must be completely slack.

b.      Crack Throttle the least little bit possible and note how the bike responds. Repeat a few times so you are sure of what is happening.

c.      Screw all 4 Idle Air Screws all the way in.

d.      Turn back out to new setting.

e.      Repeat ride test (a-d) until optimal throttle opening behavior is exhibited.

 

 

It’s always best to start at the bottom of the carb performance and work towards Wide Full Open.

 

I found a place that is totally flat and has negligible traffic.  OK, no place on earth is totally flat, everywhere has some tilt to it.  I found a place where the terrain is as flat as a cookie sheet tilted a little bit.  This is important because in order to adjust the air screws the bike must be able to move under its own power with the throttles TOTALLY closed.

 

Run all tests rolling “downhill” as it is easier to run on a closed throttle that way.

 

Talk about an exercise in self control.  It is hard for me to even think about riding my Gamma at 3mph.

 

The trick about air screws is they affect the first little bit of throttle opening.  Even 1/8 throttle is too much.  In order to test air screws one must be idling in first gear with the throttle totally closed BEFORE the test starts. 

 

I had to open my throttle stop screws another 90 degrees a bit to even reach that point.  Once it would roll along with the throttle closed the air screw adjusting began.

 

The trick is to open the throttle the LEAST LITTLE BIT POSSIBLE and then HOLD IT THERE to see what the bike does.  It is really tempting to give a little bit more throttle twist to get it to act normally.  Can’t do it or the test is invalidated.

 

Start out by turning the air screws all the way in then backing them out 1 ½ turns (which is the stock setting). 

 

Ride along at idle then crack the throttle a little and see what happens.  Do this several times to get a reliable reading.

 

Now go back and turn the screws all the way in then back them out to the next setting to be tried. Adjust the screws in ¼ or ½ turn changes until optimal throttle off->on pickup is achieved.