Brainstorm 2-stroke bogging with me....

[ran49]

Hey Norman
What Dia. Are we looking for on the needle in relation to the jet.I see where you spec the jet at .025.Thanks,Ron

 

[Norman]

Ron I went through that last night with Pablo's carb. The main jet should be 0.025 and the needle should start out at 0.070 and taper at the end to a dia. of 0.065 if i remember right Pablos carb didn't have a taper and would not rev. when I tried to open the throttle it would die unless I kept the choke half on. I chucked the needle up in my dremel and used 320 grit wet/dry sand paper to taper the needle it does this pretty fast so sand a little and then mike it. about half of the way down on the needle it should mike at about 0.068. once I'm very close to the final measurement I switched to 2000 grit wet/dry to polish it to the last half thousands.

 

[Pablo]

Norm - it did have some taper to it. Obviously not enough!

 

[Venice Motor Bikes]

This is going back the begining of the thread...if the engine dies at full throttle & you want to know if it's too rich or lean?... get the engine warmed up & then put a brand new plug in it & rev it up... the second it dies, pull the clutch so the engine doesn't keep turning & sucking in raw fuel, then immediately pull the plug out to see if it is wet or too dry... I was taught to do something similar to this for jetting cars in drag racing.

Any thoughts?

 

[Bikeguy Joe]

That'll get you in the ball park, but won't really tell you much if it only runs a second or two. Great for overall mixture checking though.

 

[Venice Motor Bikes]

Thats only what that test is for, checking mixture...

 

[Norman]

Pablo
You right it didn't have enough taper it looked like it was not finished right as the taper stopped about where it should of been getting smaller towards the end of the needle I think it was about 0.070 at the end and needed to be 0.065 heck that was a couple of days ago and my memory card seems to be short. any way it will be coming back to you soon.
Norman

 

[Pablo]

That'll get you in the ball park, but won't really tell you much if it only runs a second or two. Great for overall mixture checking though.

I agree - in this case the plug was mostly wet....misleading me.