Speedo gear RD350

[2t Fan]

Like to understand whether the speedometer gear unit on the front hub of RD350.s are common for miles p/hr and km/hr bikes ?

[Striker1423]

Like to understand whether the speedometer gear unit on the front hub of RD350.s are common for miles p/hr and km/hr bikes ?

I do believe so. They change the gear ratio in the gauge itself typically.

[bitzz]

Pretty sure the only difference is the speedo face

[pidjones]

Calibration of speed by the face and odometer by gearing in it.

[m in sc]

all yamahas run the same speedo and tach ratios. (same as kawasaki BTW) ...what matters is the gear and drive in the front hub, and whether its for a 17,18, or 19" front wheel.

[pidjones]

all yamahas run the same speedo and tach ratios. (same as kawasaki BTW) ...what matters is the gear and drive in the front hub, and whether its for a 17,18, or 19" front wheel.

I'm confused, because all of the gear part numbers for both Euro and American RD400c are the same. The difference is the clock as far as part numbers go.

[m in sc]

the gauges are all the same ratios, regardless of part numbers. I can 100% guarantee this.  euro and  NA rds all ran 18" front wheels stock.  hence why the gears are the same part numbers.

for example, 79 xs650 (19" front wheel):

HOUSING, GEAR
341-25191-01-00

79 RD400 (18" front wheel):
GEAR UNIT ASY
31A-25190-10-00

[SoCal250]

The gauge determines the measuring unit.
Generally, if it's a MPH gauge the 9th character (Design Code digit) in the Yamaha part number will be a "4". A "2" denotes KPH. This is true for pre-1979 part numbers. After that model year Yamaha went to letters for the code.

Some examples:
Yamaha Speedometer part numbers
360-83570-43-00      RD350 73-73 (USA)   MPH
360-83570-22-00      RD350 73-75 (EU)     KPH
1A0-83570-41-00      RD400C/D/E (USA)    MPH
1A2-83570-21-00      RD400C/D (CAN)       KPH
1A0-83570-21-00      RD400D (EU)            KPH
1A0-83570-41-00      RD400D (UK)            MPH
2J2-83570-A0-00      RD400F (USA)           MPH
3J7-83570-E0-00      RD400F/G (CAN)        KPH
31K-83570-G1-00     RZ350L/N/NC/NCII     MPH

[2t Fan]

thank you all for the valuable inputs