Talking to an old buddy about projects and he said that he had too many. One of the projects that he is thinking about parting with is an old ’47 flathead. He says that it is all there and ran when they put it in his basement. I am going over to his house this Saturday and was wondering if that was an easy way to distinguish between the F, FL, U, US, etc.

Thanks

TMO

'F' and 'FL' were 74 cu in overhead valve motors. For 47 it was a knuckle (last year). They also made an 'E' model which was a 61 cu in overhead valve motor. Side valve models were 45 cu in motors and designated as 'U' (74 cu in twin, medium compression), 'UL' (74 cu in high compression), 'US' (74 cu in, medium compression, side car gears). There was also a 47WL.

Take a look at a couple of the bike in the flathead section and knuckle section and you will instantly see the difference in the engine designs.

Thanks for the responce... I will look at some pictures.