"79 yz400 was the odd one out with a smaller bore [82mm] & longer stroke which doesn't necessarily mean a different length rod [i think!!] but just thought i'd mention it. Here's a thought now, Big Bore the "79 400 using an earlier [or later] YZ400 piston. Pretty sure i compared them a lifetime ago & looked the same just 85mm instead of 82mm. Someone may have done it?. Like i said, the "79 was the odd one out [but a good one] Had one brand new back in the day. Isn't it a bummer we sell one bike to get the money to go towards the next year model [talking back then] & regret not keeping it 34 years later!!, along with all the others, ohh--triumph metisse etc, depressed now, where's me beer.
