My 400 has these build dates; frame October '74 ; engine left case,September'74 / right case July '74 .My rear wheel is a Sun. My front wheel is a shouldered Akront. I thought I read here that a late build date is considered the next model year. The rear hub has KTM/ magnesium cast into it. The front hub has no markings that I can find. The front hub has 2 cracks , opposite each other, parallel to the axle. The cracks don't reach the hub ends, so can I weld it?, and if so is the hub magnesium or aluminum ?
Also is this bike considered a '74 or '75? This will be a rider, so I'm not concerned with the mismatched wheels. Thanks everyone for any onfo.
Chris
1974 Mint 400
Frame 54 410 78640
engine 4 5500708
When the dual position frame shock mount, (provisions to mount the shock in the laid down position), arrangement was introduced, it was considered a 74 1/2 model, and from your frame number, I would consider your bike a 74 1/2 model, even though the mint 400 was generally referred to as a 1975 model. It would have the shouldered Akront wheels on front and rear originally. The black Magnesium front hubs were extremely prone to cracking, but the later 78 KTM silver ones were not, but they looked similar except for the color, and were outfitted with the later Sun rims if you want to replace your front with a matching wheel to your rear. Mike
Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R
Thanks again Mike for the info. Chris
1974 Mint 400
Frame 54 410 78640
engine 4 5500708