RGS runs badly at small throttle openings

Changed today 60 pilot jets and 122 main jets and adjusted the mixture and idle speed screws according to factory manual. Now it runs much better but needs still more leaning. I may try 57 and 118 next time.

Sometimes when I close the throttle for engine braking and just before I open the clutch to change the engine bangs. I'm not shure does the sound come from the air filter or from the exhaust system. But it have done it all the time after I set the ignition advance at idle from 7 to 10 degrees. I have Ignitech sparker. Maybe that small amount of rich mixture doesn't ignite from too advanced spark (too low pressure) and ignites on the exhaust.

 
Air leaks?
Maybe try new copper crush washers at the header clamps and check carb rubbers at the head for cracks.
 
MotoJouni said:
Sometimes when I close the throttle for engine braking and just before I open the clutch to change the engine bangs. I'm not shure does the sound come from the air filter or from the exhaust system. But it have done it all the time after I set the ignition advance at idle from 7 to 10 degrees. I have Ignitech sparker. Maybe that small amount of rich mixture doesn't ignite from too advanced spark (too low pressure) and ignites on the exhaust.
Click to expand...

we get that with our Mikuni and Ignitech equipped bikes, we found the issue was too lean on a trailing throttle, to fix we raised the needles one notch
but that is with Mikuni flatslides, no idea on Dellorto's
 
Steve

Agree with Grant about checking the washers as you may well be sucking air.
What you can do is with the engine running spray some WD40 ( or similar ) around the intake manifold to the head area and see if the engine speed changes.. if it does then you have a vacuum leak. if it doesnt then rule that out.

You mention you jetting and needle and slides but dont see where you the emulsion tubes... as per Will are they new AB265's and are they all tight. It is amazing the difference a new set of emulsion tubes makes as this is where most of the metering from 1/4 to 3/4 throttle takes place. I always fit new ones and reckon this is one of the reasons by far that my RGS is so fruvelous in its use of fuel, right up there with the BM boys on the Snowy runs when I take it !!( yep BMW riders on a Laverda Snowy run go figure !! )

Where exactly do you have the issue as you say off idle is it immediately off idle or from say 1/5 throttle to around 1/4 or so.. and if you pull the choke on a tad does it make it better or worse.

Thats another thing are the rubbers on the bottom of the choke plungers soft and sealing... they can get hard over time and are often neglected... you can usually pop them out and turn them upside down to get some more life might be worth checking them.

 
Id try 122 / 55 first at this point Id be making only one change per test. At the very small throttle openings the main at 122 will not be affecting it.
If its back fireing on over run as test open choke at wide throttle opening and the snap off like you would to get the back fire and see if it makes a differance.

Ive had trouble in past with new choke plungers being slightly shorter and not having enough cable free play to get then to close correctly
Jugs
 
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