I have finally checked the timing and figured out that its 32 degrees. I changed the timing to 28 degrees but as demonstrated in the vide link given above http://www.rcuniverse.com/forum/m_8864014/tm.htm when the guy rotated the shaft either clockwise or anti clockwise it always ignited on 28 degrees. So rotation in either direction the angle was same. When i rotate my shaft anti clokwise (in the direction of rotation of prop) it fires at 28 degrees but clockwise it fires at around 40 degrees. Any comments.

However with these new setting I test for around 10 minutes on the ground. 1300 rpms low, reliable and no hesitation of engine to move from this to full throttle (previously engine was quitting if i kept the rpms less than 1800). throttle response was little better no change in top rpm.