hi guys what the glow plug number refer for ?When i change plug no 6 to 8 the engine keep stalling with fuel coming out from the exhuast so which needle to adjust first.thanks

Here is some good info, not all the answers, but a good place to start

http://209.15.36.61/rdrc/gloplugs.html

The plug numbers refer to the temperature of the plug........the lower the number - the hotter the plug is.
As for engine tuning help...try Josh Cyrul`s website-
www.cefx.net
Cheers