hi i have a 120y with a12 and hitachi dcg 306 (i think) carby i have a problem were the mixture screw does nothing fully in or out so i cant adjust it!

so i searched in google and it says you have to open the secondaries a bit and close the primary a bit i have no idea how to do this on this carby!

Any ideas will be greatful and appreciated!

Thanks!

idle circuit might be blocked!

i rebuilt the whole carb which was cleaning it also any way i can clean without desambling it preety sure i cleaned it all good!

thanks!

So you rebuilt the whole carb? And now it is working correctly?

Quote:
I have no idea why they would say that. Normally when the mixture screw has no effect, the carburetor needs cleaning. Opening/closing the throttle blades is not normally done, the linkage keeps them in sync on the Hitachi.

back off the idle speed screw all the way, to make sure its drawing from the idle circuit.id then shut off the mixture screw all the way.it shouldnt run after doing this.then open 3 turns, if this makes no difference after this you have problems.

i recall a technique, as far as i can remember, from jmac.


you turn off your engine, and then spray a generous amount of carb cleaner to the mouth of the carb, and be particular not to miss the jets visible from the outside. after that, wait for a couple of minutes, and then switch the plug lead of 2 and 3. this way, you induce backfire. turn on the engine and let then nurse it, so the backfire happens, and the engine not stalling. after 2 or 3 minutes doing this, switch off, switch back the lead of 2 and 3. and lastly, drain the fuel from the carb bowl. this is to ensure the dirt entering the bowl doesn't get sucked into the circuits again.

this technique work wonders a couple of times already.