• Home • YA6 • MT125 • AT2/CT2 • CS3 • RD200 • TD1C • TD2 • TR3 • RT2 • CanAm •
My Yamaha YL1 100cc Road Racer

This is how it looked when I built it in 1967. It wasn't quite as fast as a good 125 but handled better and weighed 150 lbs.

 

  

 

 

 

 

 

 

 

 

 

 

 

This is how it looks after I changed the rake and trail and used baby Ceriani forks. It now handles like my other frames. I also put a TA125 motor in it. This bike uses Bridgestone 2.50-18 race tires you can get at a Honda dealer.

 

My new method of holding sections together for welding the new pipes. Made from a piece of chain, threaded rod and a couple of bars.

The new pipes finished. I got the dimensions from Kevin Cameron. Also decided to start using air cleaners. I think it's faster than my MT125.

With the new pipes it makes 28 hp at 14K. I also did a little work on the transfers which Kevin recommended.

 

I made a still air box for the filter

 

   

This is one of the new heads that is half done beside an original. Vin Borbone runs Vintage Performance and makes heads for many models of vintage bikes

Vintage Performance

 

  

New heads installed and the cooling is much better. two strokes tend to lose a bit of horsepower as they heat up. I lost less with the new heads.

  

 

 

 

 

The required oil pan even though I've never seen anything come out the bottom of a two stroke
 

 

 

 

 

The crankcase originally had pieces cast into it to stuff the lower end for higher crankcase pressure.

 

 

  

 

 

 

 

I cut it all away for better flow up into the transfer ports. I'll soon see if that works.

 

 

 

I slotted the rods and honed out the big end for .001" more clearance. This seems to help the big end live.

 

  

 

 

 

 

Now I also slot the small end. Hope this makes the needle bearings live.

 

 

  

Clutch and straight cut gears from a 1984 YZ125C

  
     

 

                          

 I may be getting a dry clutch soon.  
 
 

We ran at Loudon and it's faster than my RD200. I beat my son and he's a faster rider than me but the TA gave me the advantage. Unfortunately half way though the 2nd race the needle bearings in the small end gave up.

I also have to modify the chambers to lower the peak RPM. I think 14,000 is just too much for the rod bearings.

I got a Zeeltronic programmable ignition and it has a rev limiter so I don't have to worry about exceeding 13,000 anymore.