Carb jetting

[ruairiyblaster]

Got the Graydon pipe on, awk helped me pick my jet for the mods.
It's idling abut low, but runs perfect apart from at full revs it's as if sometimes throttle sticks on abit. Plug chop was perfect any advice

 

[Surfrjag]

It could be an airleak or you may need to adjust your air screw. Make sure your carb top is tight and check that your cable isnt bound up somewhere then turn your air screw in a half. This will richen it up some. You will most likely have to turn the idle up some when you do this. If this doesnt work then you should probobly do a leakdown test.

 

[Awk08]

proper carb tuning starts at the bottom and works up, each lower circut can effect the rich/lean of the circuts above it, if you lower or raise the fuel level in the bowl by adjusting the floats, all circuts are effected.
richen or lean the pilot or needle circuts, you will need to perform main jet plug chops again to confirm it has not been effected by the lower settings.
this starts with a leakdown tested, airtight motor.

http://www.blasterforum.com/carburetor-138/float-heights-how-adjust-them-50565/

http://www.blasterforum.com/carburetor-138/adjusting-your-airscrew-pilot-jet-51060/

the needle clip setting reportedly can also be plug chopped by doing 1/2-3/4 throttle runs, but i've never done it, i richen the needle till it blubbers then lean it back down 1 clip setting

after the float level and pilot/needle circuts are correct, then plug chop that main to perfection, or +1 size to be on the safe side, adjust for varying temps and elevations, plug chopped at 80f degrees may fry at 30f, plug chopped at 2000'+ elevation may fry at sea level.