I changed the timing chain, and was "I thought" very careful to get the marks on the cam gear aligned perfectly with the the timing marks on the crank, by the book. When I put it together it ran fine, but seemed down on power, and it would not take all of the gas. If you held the throttle wide open it would surge up and down instead of taking the gas. I suppose it is a stupid mistake, but I share this so that the next guy does not do the same thing. I set the crank marker arrow dead between the two little marks on the crank, on the left side cover, but that was WRONG. I was suppose to set the crank arrow on the T-Mark, just beyond the double lines. Once I corrected this little problem she runs like a champ, back to spinning the rear tires. WHOO HOO!