posted in diy forum thru ignorance of which forum to use, sorry! i have a 2510 diesel mule that will rev for a little bit when first started. after that it idles fine but won't rev. i have changed the fuel filter and air filter, drained and cleaned the fuel tank all to no avail. took the plug out of bottom of muffler and blew back thru the exhaust exit and air came out the plug holle.don't know if there could be a baffle farther back in the muffler that is plugged or not. any thoughts or suggestions are appreciated. thanks!