Troy,

I noticed a slight performance gain after setting the tappet clearance to 0,05mm. Is this the case if they get too much off the specified gap? Both tappets had slight more than 0,1mm gap before I set them to 0,05mm.

As you problaby notice I don't have very much knowledge with 4 strokes yet. I bought a Oxalys 50 and a YS63S to try these engines out before I go for the real thing (160 or 170) in my 2M pattern plane. After burning about 12 litres of fuel with this combination I think it will be hard to go back to 2 strokes. The engines settings is rock stable, and people ask me if I run a 90 when they see how the plane performs! I have become a true YS fan!

Regards,
Dag Ragnar