eh thanks alot there Jersey, i'll do some checking. i've always thought that they were governed too low, if you look up the power band of a 18 hp briggs you'll see the powerband is from 2200 rpm to about 4200 rpm , they cut off 65% of the potential horse power by governing it to max out at 2800 to 3200, you mentioned that it needs new springs ,do you know what rpm the valves start floating ?