Has any one tried synthetic oil in the crank case and dif? I wonder if this might help the brake in period.

 

You don't want to use synthetic oil during break in or things won't seal right. Put it in after breakin. I made the mistake on one of my quads. I bought 2 identical 150cc quads, one for me and one for the wife. I put synthetic in mine and regular in hers. After about 20 hours on each quad, mine has 145 psi compression and hers has almost 160 psi compression. I have adjusted the valves correctly on both so it's due to the oil.