1970 Honda SL175

The Ancient Adventure Bike | Est. 2025

Main Photo of the 1970 Honda SL175

My trusty SL175, out on a logging road.

Key Specifications

Engine Type:
174cc, air-cooled, parallel-twin, 4-stroke
Carburetors:
Dual 20mm Keihin PW-series carburetors
Max Horsepower:
19 bhp @ 9,500 rpm
Transmission:
5-speed, wet multi-plate clutch
Final Drive:
428 Heavy Duty Chain
Suspension (Front):
Telescopic fork with polished sliders
Suspension (Rear):
Dual preload-adjustable chrome shocks
Front Brakes:
Drum Brake
Rear Brakes:
Drum Brake
Curb Weight:
120 kg / 265 lbs
Fuel Capacity:
8 liter / 2.1 U.S. gal

A Brief History & My Thoughts

In the spring of 2025, I was watching a YouTube video about Williams Vintage Motorcycles in Xenia, Ohio when I saw this bike sitting in their showroom. I had been toying with the idea of getting a small lightweight bike and this bike just grabbed my attention.

I called the bike shop and was told the bike wasn't for sale yet, but I was welcome to stop by and have a look at it. It took several visits, but eventually, I loaded it on the trailer and brought it home with me.

It Looks Much Better Than It Is...

Now while the bike is a real beauty to look at, it has some mechanical problems. My first ride around the block, had me wondering if it was going to make it back to the garage! A through carb clean and rebuilt along with bring the air filters back into spec and it was time for another road test.

Something still was right, and a leak down test showed that the valves were leaking pretty badly. A top end rebuild is scheduled for this winter, but with some creative carb tuning, the bike will hum along at 50 mph so I'm going to ride it a bit before winter weather hits Central Ohio.

SL175 on it's first shake-down ride...
SL175 on it's first shake-down ride...

I had one of these bikes way back-in-the-day when I was 14 years old. It has proven to be just as much fun to ride now as it was back then. Most old reviews claim the bike will do 75 mph when running properly so I have high hopes for this one after my winter project of a top end rebuild.