We now have available 12 volt conversion kits for DTs 250/360/400 1974-79:

The problem with these machines is that Yamaha altered the generators often and also issued several factory re-calls adding different parts to some meaning that you cannot be sure what is actually fitted. They even had dealers rewinding the charge coils at one point! Yamaha tried many different combinations which means that to ensure good results you have to replace the lighting coil for a dedicated 12 volt unit.  

Our kit replaces all the lighting coils Yamaha used - no matter which configuration you have (so long as someone hasn't fitted an DT1/2/3 or RT generator) with a standard 12 volt one ensuring the charging system works properly in all cases.

Some more background information is available here:

http://www.rexs-speedshop.com/WebRoot/Store2/Shops/es143131/MediaGallery/Rexs_DT12VC_conversion_Information_Page.pdf

Link to News page:

http://www.rexs-speedshop.com/epages/es143131.sf/en_GB/?ObjectPath=/Shops/es143131/Categories/%22News%20%26%20Special%20Offers%22

Looks good Rex