Model designation ?

[evo550]

364, any ideas what it may be ?

[Frank M]

for example:

This Yamaha 364-85540-13-00 CDI UNIT ASY part is also used on these models and components:
 

1973 MX250 C-D-I MAGNETO

1973 MX250 ELECTRICAL

1973 MX250A ELECTRICAL

1973 MX360 C-D-I MAGNETO

1973 MX360 ELECTRICAL

1974 MX250A C-D-I MAGNETO

1974 MX250A ELECTRICAL

1974 MX360 ELECTRICAL

1974 MX360A C-D-I MAGNETO

1974 MX360A ELECTRICAL

1974 YZ125A ELECTRICAL YZ125A - B

1974 YZ250A ELECTRICAL

1974 YZ360A ELECTRICAL

1975 MX250B ELECTRICAL

1975 YZ250B ELECTRICAL

1975 YZ360B ELECTRICAL

1976 YZ125C ELECTRICAL YZ125C
 
[http://www.boats.net/parts/detail/yamaha/Y-364-85540-13-00.html]

[evo550]

Thanks Frank,
It's a twin shock Yamaha frame number, so I'm assuming a MX 250 or 360 or if my planets aligned a Yz "A", although I very much doubt it.
Did the 250 and 360 mx's share the same frame number?

[Iain Cameron]

no the mx250 73/74 is 364 , the mx360 73/74 is 365 and the sc500 73/74 is 363 all the frames are the same .

[Freakshow]

as Iain says its a MX250, later serial number would be A model yellow, early numbers are silver tank.

when he say all the frames are the same, he means they look the same but have differant head stem numbers.  the engines however are prity much all differant inside as are the barrels etc. Body work on the 250/360 is much the same the 500 has differances like exht and side cover etc.

Still 364 make great all round pre 75 bikes, and heaps out there now beign raced.  There kinda bullet proof and parts are plentiful and when they run out you can just use the DT250 stuff