I FOUND THE REPLACEMENT...STENS 255-507 ELECTRIC PTO CLUTCH/OGURA MA-GT-EXM3XS. $235.OO FREE SHIPPING.FRO OREGON POWER EQUIPMENT, SALEM,OREGON. ORDERED IT SATURDAY AFTERNOON AND THER MAILMAN HANDED IT TO ME MONDAY AFTERNOON. IT HAS A 1 INCH BORE AND 3 INCH OVERALL HEIGHT(PERFECT). THE ELECTRICAL CONNECTOR WILL HAVE TO BE CHANGED AND THE 6 INCH SHEAVE OR PULLEY WILL REQUIRE A B68 BELT(1 INCH BIGGER). THE KEY WAY EXTENDS ALL THE WAY THROUGH, WHICH DOESN'T MATTER BECAUSE IT IS STOPPED ON THE CRANKSHAFT. I RECOMMEND CUTTING OFF THE ELECTRICAL CONNECTOR FROM THE OLD CLUTCH AND SOLDERING IT ON THE NEW ONE. YOU'LL HAVE TO READJUST THE MOWER DECK TENSION SPRING TO MINIMIZE BELT SLIPPAGE. THERE MAY BE CHEAPER ONES OUT THERE,BUT I'M MORE THAN SATISFIED. IT'S RUNNING GREAT.
Good find, Steve!!!
This is the only way to keep these mowers going now, finding alternatives to Yamaha parts.
Will have to keep this post forever now!