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Welcome to the 1969 Yamaha DT1-S / DT1-SA Forum. USA DT1S Model Code 264 & model code 270 for the Australian DT1SA. Feel free to post anything related to this model in the category. Anything new, will be added to this section. The Factory color for the DT1S was: Candy Orange. The USA Vin number range for the DT1S was: DT1-90101 to 91573. If you see any errors, please contact me privately. There were many errors, in the early Yamaha literature. I will make some error's of my own.
1969 Yamaha DT1S Specifications
Model 1969 Yamaha DT1S
Dimensions:
Overall Length 81.1 In. / 2,060MM
Overall Width 35.0 In. / 890MM
Overall Height 44.5 In. / 1,130MM
Wheelbase 53.6 In. / 1,360MM
Min. Ground Clearance 9.6 In. / 245MM
Weight:
Gross 256 Lbs. / 120Kg
Net 232 Lbs. / 109Kg
Performance:
Max, Speed 70 MPH / 112Km/h +
Fuel Consumption 94 MPG @ 25 MPH / 40Km @ 40Km/h
(On paved level roads)
Climbing Ability 37 Degree
Min. Turning Radius 82.6 In. / 2,100MM
Braking Distance 40 Ft. @ 30 MPH (12.5M @ 50Km/h)
Engine:
Model DT1
Type 2 Stroke, Gasoline
Lubricating System Separate (Yamaha Autolube)
Cylinder Single, forward inclined 5 Port
Displacement 15 cu. in. (246cc)
Bore X Stroke 2.77 X 2.52 In. (70MM X 64MM)
Compression Ratio 6.8:1
Max Power 21 BHP/7,000 RPM
Max Torque 16.8 Ft.-Lbs @ 5,000 RPM
Piston Skirt Clearance .0016 - .0018 In. / 0.40 - 0.45MM
Starting System Primary-Coupled Kick
Ignition Timing B.T.D.C 3.2 MM +/- .011 - 0.13 MM
NGK Spark Plug & Gap B-7E (N) 0.5-0.6 MM
Contact Break Point Gap 0.011 - 0.013 Inch / 0.30 - 0.35 MM
Volt Reg. Adjustment -
(Volts @ RPM - No load)
Cutout Relay Adjustment -
Condenser Capacity .22UF (Microfarad)
Carburetor:
Type VM26SH
Main Jet # 160
Jet Needle 5D1 - 3
Air Jet 0.5
Needle Jet 0 - 2
Cut Away 2.5
Pilot Jet (#) 35
Air Screw (turns out) 1 1/2
Starter Jet (#) 60
Float Level 14.1MM
Intake:
Air Cleaner Wet, Foam Rubber
Transmission:
Clutch Wet, Multiple Disk
Primary reduction system Helical Gear
Primary reduction ratio 3.095 / (65/21) Teeth
Trans Oil Capacity 1.06 Qts / 1,000cc
Gear Box:
Type Constant Mesh, 5 Speed Forward
1st Gear teeth & Ratio 2.533 (38/15)
2nd Gear teeth & Ratio 1.789 (34/19)
3rd Gear teeth & Ratio 1.304 (30/23)
4th Gear teeth & Ratio 1.000 (26/26)
5th Gear teeth & Ratio 0.767 (23/30)
Secondary reduction system Chain
Secondary reduction ratio 3.143 (44/14)
Chassis:
Frame Tubular-Double Loop
Front Suspension System Front Telescopic fork
Rear Suspension System Swinging Arm
Fork Oil Capacity 210cc (7.1 Oz.)
Front Cushion System Coil Spring / Oil Damper
Rear Cushion System Coil Spring / Oil Damper
Steering System:
Steering Angle 49 Degrees both left & right
Caster 60.5 Degrees
Trail 137MM
Braking System:
Type of brake Internal Expansion
Front Operation System Right hand operation
Rear Operation System Right foot operation
Tire Size:
Front 2.75 - 21 - 4PR Trials Universal
Rear 4.0 - 18 - 4PR Trials Universal
Front Tire Pressure 14 P.S.I
Rear Tire Pressure 17 P.S.I
Oil Pump:
Adjustment Stroke Min 0.20 - 0.25 MM
Adjustment Stroke Max 1.85 - 2.05 MM
Dynamo:
Model FZA - 1BL
Manufacturer Mitsubishi Elec.
Battery:
Model MV1-6
Manufacturer Nippon Battery
Capacity 6V 2AH
Lighting:
Head Light 6V 35W/35W
Tail Light 6V 5.5W
Stop Light 6V 17W
Meter Light 6V 3W X 2
High Beam Indicator Light 6V 1.5W
Tanks:
Gasoline Tank Capacity 2.5 Gallons
Oil Tank Capacity 1.7 Quarts
Chain:
Tension (Up & down free play) 20MM (25/32)
The 1969 Yamaha DT1S Rider's Manual is Located: CLICK HERE
The 1968-1971 Yamaha DT1 Combined Service Manual is Located: CLICK HERE
The USA 1969 Yamaha DT1-S Parts Manual is Located: CLICK HERE
The Australia 1969 Yamaha DT1-SA Parts Manual is Located: CLICK HERE
The 1969-1971 Yamaha Autolube adjustment and Color Codes are Located: CLICK HERE
The Australia 1969 Yamaha DT1-SA Article is Located: CLICK HERE
The Australia DT1SA price list is located: CLICK HERE
It's a 105 degrees Fahrenheit here today, which kind of forces me to stay indoors, and do other unplanned things ... like contribute to this forum topic.
Devin did a fine job addressing much of what I probably would have said, but I will add a few more comments.
Although the American DT1S and the Australian DT1SA are very similar models that morphed out of the DT1B model, I want to make sure everyone understands they are not identical. First off, they have different Yamaha model prefix numbers. Model 264 for the USA, and model 270 for the Australian version.
As for the high front fender belonging on these two DT1S models . . . no, it never actually happened . . despite a few pictures in the Yamaha riders manual that has led folks to believe so.
The note below is found inside the front cover of some (but not all) DT1S owner manuals.
THEORY: Think about it ... The owners/riders manuals had to be finished and ready to go (printed) when the very 1st DT1S came down the assembly line. At some late point, (just before bike production), Yamaha must have scrapped the idea of a high front fender, and went with the low fender instead .... they weren't about to redo all of the manuals that they had already made.
Furthermore, the parts manual for both models show a low fender, the same part number as used on the DT1B model.
The tachometer gauge on both models was of the larger version that matched the size of the speedometer. The USA DT1S had a 21 inch front tire, whereas the Australian model stayed with the fatter 19 inch tire.
A couple more things . . . the members at the 68/69 DT1 group have been calling the DT1S transmissions "close ratio", when in fact, they are "wide ratio"
(Study the chart further below, and compare the different transmissions ratios.)
Secondly, the "S" in the Australian DT1SA stands for "Station", (not scrambler) as someone had posted on that site. The SA model even had a sticker on the oil tank that identified it as so. The models price list found elsewhere in this DT1S thread, also calls it a Station model. I suspect the "A" stands for Agricultural , but can't prove that ... yet.
I have not seen any proof (either way) that the American model "S" stood for scrambler, but would be happy to learn, if someone can produce Yamaha documentation that clarifies that. 😉
68/69 DT1 A&B Enduros . . . . Exception: 69 DT1-S model
. . . Pinion/Wheel . . . Ratio
1st . . . 13/29 . . . . . . . 2.231
2nd . . . 16/26 . . . . . . 1.625
3rd . . . 19/23 . . . . . . 1.211
4th . . . 21/21 . . . . . . 1.000
5th . . . 23/19 . . . . . . 0.826
Overall Ratio Spread . . . 1.405 = Close Ratio
**************************************
69 DT1S & DT1SA Models
. . . Pinion/Wheel . . . Ratio
1st . . . 15/38 . . . . . . 2.533
2nd . . 19/34 . . . . . . 1.789
3rd . . . 23/30 . . . . . . 1.304
4th . . . 26/26 . . . . . . 1.000
5th . . . 30/23 . . . . . . 0.767
Overall Ratio Spread . . . 1.766 = Wide Ratio
**************************************
70 -74 250/360 - MX Models
. . . Pinion/Wheel . . . Ratio
1st . . . 16/36 . . . . . . . 2.250
2nd . . . 20/33 . . . . . . 1.650
3rd . . . 23/29 . . . . . . 1.261
4th . . . 26/26 . . . . . . 1.000
5th . . . 29/23 . . . . . . 0.793
Overall Ratio Spread . . . 1.457 = Close Ratio
**************************************
. . . 70 -76 250/360/400 Enduro Models
. . . Pinion/Wheel . . . Ratio
1st . . . 15/38 . . . . . . 2.533
2nd . . 19/34 . . . . . . 1.789
3rd . . . 23/30 . . . . . . 1.304
4th . . . 26/26 . . . . . . 1.000
5th . . . 30/23 . . . . . . 0.767
Overall Ratio Spread . . . 1.766 = Wide Ratio
.