ricksrj58 274 #1 Posted 9 hours ago after flushing the tank a new filter and cleaning carb 5 times and finding no vacuum leakes . I started the tractor and it ran smooth, i then took the tractor for a test ride and then it started surging. What else could cause this? Share this post Link to post Share on other sites
sqrlgtr 3,655 #2 Posted 8 hours ago On my 520H it was the 2 piece intake manifold. It was leaking where it goes together causing it to suck air and would surge. You have to take manifold off to fix right, not too bad of a job but isn't to fun either. May as well decarb, adjust valves, etc etc. why you have it tore apart that far also. 1 Share this post Link to post Share on other sites
ri702bill 12,743 #3 Posted 3 hours ago Removing the heads to de-carbon the components is a required routine maintainence task. It also gives you an opportunity to visualy check the condition of the valves & seats, the walls & pistons for wear and deterioration. Well worth the peace of mind. Share this post Link to post Share on other sites
