yanmar 3TN smoking

[engmachshop]

{10/07} cust. says that one of his employees Put gas in the diesel fuel tank NOW the 3TN engine Smokes & when they did a compression test was Surprised to see that ALL 3 Cyl.s have Same Compression [would have thought that the [gas] would have damaged 'cyl or piston/ring] BUT it didn't???? BUT they can not figure out what is causing the Smoking , said that the rings Look Good[none broken & all seem to fit in Piston glands Tight! can get customer to replace BUT would Hate to tell him to change & then they 're-assemble engine' get engine & Still Smokes ?
This engine is for a Federal Prison[they don't mind spending the $ if we tell them , might be the problem but if it isn't , their Time/$/labor would be for Nothing !?!?
THANK U for any & all H E L P
butch @butch's auto&diesel machine shop