Hi can any-one help me with a power head identification ,I bougt it for spare parts as a 25hp,manual start but i'm not so sure after stripping it .I got it for the pistons and crank ,to rebuild my 1982 25hp electric start only to find different pistons , carb and con rods ,seems to be the same bore size . the carb also has a nylon insert restricting the throat of the air intake . so i might just repair this head as a spare if i know what it is . the only number i have is on the plug in the cylinder block A0652278 any help appreciated thanks