C70 dimensions, torque specifications, model history and more.
Specifications
Honda C70 Specifications
|
|
English |
Metric |
| Dimensions |
Overall Length |
71.1 in. |
1805 mm |
| Overall Width |
26.2 in. |
685 mm |
| Overall Height |
39.2 in. |
995 mm |
| Wheelbase |
46.5 in. |
1180 mm |
| Seat Height |
29.9 in. |
760 mm |
| Min. Ground Clearance |
5.1 in. |
130 mm |
| Dry Weight |
184 lbs. |
83.5 kg |
| Frame |
Type |
Pressed & tube steel type |
| F suspension, travel |
Leading link, travel 2.2 in. (55 mm) |
| R suspension, travel |
Swing arm, travel 2.4 in. (60 mm) |
| F tire size, pressure |
2.25x17-4PR, 28 psi |
2.25x17-4PR, 2.0 kg/cm2 |
| R tire size, pressure |
2.50x17-6PR, 28 psi (40 psi when laden) |
2.50x17-6PR, 2.0 kg/cm2 (2.8 when laden) |
| F brake, lining area |
Cable, Internal expanding shoes, area 13.4 sq-in. (86.4 sq-cm) |
| R brake, lining area |
Rod, Internal expanding shoes, area 13.4 sq-in. (86.4 sq-cm) |
| Fuel capacity |
1.05 US gal./4.0 l. |
| Fuel reserve capacity |
0.21 US gal./0.8 l. |
| Caster angle |
64 deg. |
| Trail length |
2.8 in./ 70 mm |
| Engine |
Type |
Air cooled, 4 stroke OHC engine |
| Cylinder arrangement |
Single cylinder 80 deg inclined from vertical |
| Bore and stroke |
1.850 x 1.630 in. |
47.0 x 41.4 mm |
| Displacement |
4.4 cu-in. |
72cc |
| Compression Ratio |
8.8 : 1 |
| Valve train |
Chain driven overhead camshaft |
| Maximum horsepower |
5.0 BHP at 7000 rpm |
| Maximum torque |
3.9 lb/ft at 5500 rpm |
0.56 kg-m at 5500 rpm |
| Oil capacity |
0.74 US qt. |
0.7 l |
| Lubrication system |
Forced and wet sump |
| Cylinder head compression pressure |
178 +/-7 psi at 1000 rpm |
12.5 +/-0.5 kg/cm2 at 1000 rpm |
| Intake valve opens |
0 deg BTDC |
| Intake valve closes |
20 deg ABDC |
| Exhaust valve opens |
25 deg BBDC |
| Exhaust valve closes |
5 deg ATDC |
| Valve tappet clearance |
IN-EX 0.0002 in. |
IN-EX 0.05mm |
| Idle speed |
1500 +/-100 rpm |
| Carburation |
Carburettor Type |
Piston valve (slide), 14mm (0.55") venturi bore |
| ID. Number |
1980 model: PB32A |
1981 model: PB32C |
| Float Level |
0.42" |
10.7mm |
| Drive Train |
Clutch |
Wet, multi plate, semi-auto centrifugal type |
| Transmisson |
3 speed constant mesh |
| Primary reduction |
4.058 |
| Gear Ratio 1 |
3.272 |
| Gear Ratio 2 |
1.722 |
| Gear Ratio 3 |
1.190 |
| Final reduction |
2.571, drive sprocket XXT, driven sprocket XXT |
| Gear shift pattern |
Left foot operated return system, N-1-2-3 |
| Electrical |
Ignition |
Flywheel magneto |
| Points Gap |
0.012 - 0.016" |
0.3 - 0.4 mm |
| Ignition Timing "F" Mark |
15o BTDC, Static |
| Advance Start |
1875 rpm |
| Full Advance |
30o BTDC, at 2900 rpm |
| Starting System |
Kick starter and/or starter motor |
| Generator |
Flywheel AC generator, 57W at 5000 rpm |
| Battery Capacity |
6 V, 11 Ah |
| Spark plug (normal) |
NGK C7HS or ND U22FS |
| Spark plug (cold climates) |
NGK C6H or ND U20FS |
| Spark plug (high speeds) |
NGK C9H or ND U24FB |
| Spark Plug Gap |
0.024 - 0.028" / 0.6 - 0.7 mm |
| Fuse Capacity |
10 A |
{slider Torque Specifications}
Torque Specifications
|
|
|
|
Torque |
|
Item |
Quantity |
Thread dia. (mm) |
kg-m |
ft-lb |
| Engine |
Cylinder Head Cover |
4 |
6 |
0.9 - 1.2 |
7 - 9 |
| Camshaft Sprocket |
3 |
5 |
0.5 - 0.9 |
4 - 7 |
| Clutch Locknut |
1 |
14 |
3.8 - 4.5 |
28 - 33 |
| Final Drive Sprocket |
2 |
6 |
1.0 - 1.4 |
7 - 10 |
| Flywheel |
1 |
10 |
5.5 - 6.5 |
40 - 47 |
| Spark Advancer |
1 |
6 |
0.9 - 1.2 |
7 - 9 |
| Frame |
Steering Stem Nut |
1 |
22 |
6. 0 - 9.0 |
43 - 65 |
| Handlebar Setting Nut |
2 |
8 |
2.0 - 3.0 |
14 - 22 |
| Steering Lock |
2 |
6 |
0.6 -1.3 |
4 - 9 |
| Front Axle Nut |
1 |
10 |
3.0 - 4.0 |
22 - 29 |
| Engine Hanger Bolt |
2 |
8 |
2.5 - 3.5 |
18 - 25 |
| Rear Axle Nut |
1 |
12 |
4. 0 - 5.0 |
29 - 36 |
| Final Driven sprocket |
4 |
8 |
2.0 - 2.5 |
14 - 18 |
| Rear Brake Torque Link |
2 |
8 |
1.0 - 2.0 |
7 - 14 |
| Rear Shock Absorber |
4 |
10 |
2.0 - 3.0 |
14 - 22 |
| Foot Peg |
4 |
8 |
2.0 - 2.5 |
14 - 18 |
| Swing Arm Pivot Bolt |
1 |
10 |
3.0 - 4.0 |
22 - 29 |
| Front Suspension Pivot Bolt |
2 |
8 |
1.0 - 2.0 |
7 - 14 |
| Front Suspension Pivot Bolt |
2 |
8 |
2.0 - 3.0 |
14 - 22 |
| Front Shock Absorber Upper Bolt |
2 |
8 |
2.5 - 3.5 |
18 - 25 |
| Front Turn Signal Stay |
4 |
|
0.35 - 0.5 |
2.5 - 3.6 |
| General |
5 mm bolt/nut |
|
|
0.45 - 0.6 |
3.3 - 4.3 |
| 6 mm bolt/nut |
|
|
0.8 - 1.2 |
6 - 9 |
| 8 mm bolt/nut |
|
|
1.8 - 2.5 |
13 - 18 |
| 10 mm bolt/nut |
|
|
3.0 - 4.0 |
22 - 29 |
| 12mm bolt/nut |
|
|
5.0 - 6.0 |
36 - 43 |
| 5 mm screw |
|
|
0.35 - 0.5 |
2.5 - 3.6 |
| 6 mm screw |
|
|
0.7 - 1.1 |
5 - 8 |
| 6 mm flange bolt/nut |
|
|
1.0 - 1.4 |
7 - 10 |
| 8 mm flange bolt/nut |
|
|
2.4 - 3.0 |
17 - 22 |
| 10 mm flange bolt/nut |
|
|
3.0 - 4.0 |
22 - 29 |
Manuals
These will open as PDFs

Adjusting Timing
http://ct90-ct110.com/Adjusting-Timing.html
NOTE: Start with a valve inspection and possible adjustment, if your CT is not operating properly, even if it seems your problem is not related to the valves! If you just purchased a CT, start with the valve inspection and adjustment just to make sure everything is OK or if the engine doesn't want to start or is not operating properly. The second step should be inspecting and/or adjusting the contact breaker points, you can then return here to inspect and/or adjust the timing.
There are two methods for inspecting and adjusting the timing;
- Static timing
- Dynamic timing
1981 Honda C70 passport parts Catalog
Valspar 85201 gloss Exotic Sea at a Lowes
honda, c70, passport, 1981
The 1964 Honda Trail 90, Model CT200 was also manufactured
in 1965, with essentially no change in common characteristics.
The Honda parts listing always mentions the CT200 as a 1964 and
does not mention 1965. The ending Serial or VIN Number for the
year of 1964 is unknown. The year designation found on state
titles or registrations usually refers to the year in which the
CT200 was first sold. Production and dealer ordering (often
controlled by American Honda) sometimes left CT200's on dealer
floor rooms into the following years. The 1964 model introduced an engine skid
plate, integrated the speedometer as part of
the headlight bucket, and added
metal folding foot-pegs.
I promised myself I wouldn't start on this until the C70 is assembled. For the moment here are some photos of it's gen one carb.
The 1964 Honda Trail 90, Model CT200 was also manufactured in 1965, with essentially no change in common characteristics. The Honda parts listing always mentions the CT200 as a 1964 and does not mention 1965. The ending Serial or VIN Number for the year of 1964 is unknown. The year designation found on state titles or registrations usually refers to the year in which the CT200 was first sold.
Production and dealer ordering (often controlled by American Honda) sometimes left CT200's on dealer floor rooms into the following years. We have seen several cases of CT200's with titles stating a year late into the 1960's or even the early 1970's. This is the first year with an engine skid plate. This is the first year of the speedometer being part of the headlight bucket, with a shape that was like a smooth circle section on top and a flat bottom. This is the first year for the metal folding foot pegs.
Motorcycle Riding with Stan Kolby. This is a full day motorcycle ride through the Danskin Mountains. The terrain ranges from easy USFS roads to three-attempt hill climbs.
Everything in the electric start system focuses on one thing - the "neutral switch". It isn't really a "switch". It's actually a plastic and metal plug under the countershaft sprocket cover with a metal circuit running through it from a wire on the outside to a contact on the inside end.
Electrical problems can pop up at any time and can seem hard to fix but they really aren't. Most of the time, anyway. Most everything can be "Proved" (tested) with an Ohmmeter and a some things can be proved with a simple circuit tester.
When honda made xl350 r the OEM carburetor insulator, or intake manifold, listed for a mere $60. Honda founder Soichiro Honda promised that stock parts for any Honda manufactured would always be available. With his passing in 1991 the MBAs took over and scuttled that promise.
The other problem is Honda didn't sell a lot of these two-carb 350s . As a result there just aren't that many replacement parts around: OEM or aftermarket. Enter Ebay . . .
The Honda Super Cub and its variants: C100, C50, C70, C90, C100EX and C70 Passport is the most popular motor vehicle in the world! It has been in continuous manufacture since 1958 with production surpassing 60 million in 2008.
The Super Cub built the Honda Motor company. It is a simple motorcycle with a four stroke single cylinder engine ranging in displacement from 49 to 109 cc (3.0 to 6.7 cu in).
The Super Cub was developed on the concept of a two wheeler for everyman, one that would appeal to both developed and developing countries, urban and rural. The new motorcycle needed to be technologically simple to survive in places without up to date know how and access to advanced tools or reliable spare parts supplies.
Honda partner Takeo Fujusawa's concept required that it could be ridden with one hand while carrying a tray of soba noodles. Fujusawa sold the concept to Soichiro Honda with the promise, "If you can design a small motorcycle, say 50 cc with a cover to hide the engine and hoses and wires inside, I can sell it. I don't know how many soba noodle shops there are in Japan, but I bet you that every shop will want one for deliveries."
Keihin Stock Carburetor 1981 Honda c70 Passport
Keihin PB32C Specifications
| Venturi Dia. |
14mm (0.55") |
| Identification # |
PB32C |
| Float level |
10.7mm (0.42") |
| Main Jet |
#88 |
| Slow Jet |
#35 |
| Jet Needle |
72 C |
| Pilot Screw turn-out |
2.5 |
I bought this in 2005 as an all around go-to bike. $1000 on CL. It has a leaky seal. A cobra exhaust that is loud enough to hear a mile away. From the start, it was a tough starter. Turns out to be a cracked carburetor insulator. More on that later.