Home YA6 MT125 AT2/CT2 CS3 RD200 TD1C TD2 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

 

 

New TA125 heads. I had to make these after I destroyed one of the originals. This was before they were deburred.

 

 

New head beside an original after abrasive finishing.

 

 

 

 

 

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.  
  The next project will be to weld up the combustion chambers on some RD200 heads and machine them to fit. They have much larger fins and will cool better plus I had a crank failure and ruined one of the special heads I machined.

 

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

WE ran at Loudon the next week 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.