DeWayne Utrup
Member
I have been playing with a dyno. Last night I put my 650 gas tractor on and was very short on power. Mechanically the engine is in great shape. The fuel pump and carburetor were recently rebuilt. My manual calls for 9.5d advance at 400 rpm and 20d at 800. At idle (380 rpm) the tractor starts and runs very sweet at about 20d advance but then at high idle (1650 rpm) it is running about 40d advance. While it was under load I changed the timing to 30d advance and had a 12 hp increase but when I put it back down to idle it ran rough. I am not planning to pull this tractor but I always like to have them running at factory specs and it is fun learning from you folks. Thanks in advance.