OzVMX Forum

Marque Remarks => Yamaha => Topic started by: TT5 Matt on November 28, 2009, 10:55:06 pm

Title: yz400def top on 250 bottom
Post by: TT5 Matt on November 28, 2009, 10:55:06 pm

can you fit a yz400 top on a it250d bottom end? has anyone tried or do the cases need machining?

Title: Re: yz400def top on 250 bottom
Post by: mboddy on November 30, 2009, 07:41:01 am

You'll need YZ400D/E or IT400D/E cases.
But the good news is that I'll swap you my spare YZ400D barrel and head for your IT250D cases.
From memory the barrel is either 1.00mm or 1.5mm oversize and has been ported. 

Title: Re: yz400def top on 250 bottom
Post by: mboddy on November 30, 2009, 07:43:16 pm

You will need a crank but the gearbox, clutch and ignition are all the same and so you just have to stick it all into the cases.
It is all detailed here:
http://www.yamahait.com.au/forum/index.php/topic,50.0.html (http://www.yamahait.com.au/forum/index.php/topic,50.0.html)

Title: Re: yz400def top on 250 bottom
Post by: crossedup2 on November 30, 2009, 10:17:54 pm

Hi Matt

The simplest thing is to find a DT400 D/E/F and just change the gear sets. Cases and crank are the same as the YZ400 D&E. 1M1 I think are the numbers your looking for. Everything else will do the job. Get Lozza to port it, fit a YZ piston and get set for the world of Big Bores.

Peter

Title: Re: yz400def top on 250 bottom
Post by: jimg1au on November 30, 2009, 10:39:51 pm

matt
i think i have the above stuff in a box under the beanch.