Dellorto idle speed screw backing out

Spondonrider

Hero member
Location
Colorado
Anyone else had a problem with the idle speed screw (on a bank of three Dellortos) backing out? It only takes about 15 minutes of riding for the thing to back out enough that the bike no longer idles when I release the throttle. When turning the screw it feels pretty much normal, with the resistance they usually have and yes the spring is in place. Any ideas on how to tighten things up? I did try putting some silicone sealer on the screw to glue it in place a bit but it still moved.
 
Is the o-ring with its washer in front of the spring?
The o-ring holds the screw in place more than the spring does, and is necessary as it seals the screw. Make sure it isn?t thin and worn.
 
Wrong screw methinks.
                                Dave
 
It is probably a harmonic that is causing the screw to loosen.Tracking the cause down could be a pain though,anything from a loose motor mount to the airbox[if any] pulling the carbs up or down can make seemingly unrelated parts jump and shake.Checking the carb sync. might be a good place to start.
A light drop of Blue loctite would hold the screw and might still allow toolless adjustment or maybe some gummy non drying Permatex would work too.
 
A new O-ring and washer would be best, Loctite wick-in, 290 i think, anti-vibration situations, does not harden, still allows adjustment of set screws.
 
Back
Top