Here is some information sent to me by dhjunkie  (Scott) 

Hi
I bought my mossbarger new because i live in California and ride primarily in the desert and 
got tired of waiting for the motor to cooldown.  Out of the box it works terrifically,  lot more 
power than the stocker and could run all day with out overheating.  Then being the
habitual tinkerer that I am,  I wanted more power,(it was time for a rebuild anyways).  So I tore 
it apart and started thinking of what I could do.  First on the list was the head(combustion chamber 
didn't burn the gasses that efficiently),  welded it up and machined in a standard dome and polish.  
Next was the intake ports just a little surface work to make things even and same with the exhaust 
port also polished them.  then went down to the transfer ports(this is where most of the two stroke 
power is made) I did took a new gasket and glued it to the case and then another to the underside 
of the cylinder and tapered the ports to the gasket in effect port matching the two while increasing
their dimensions(only smooth this area you need some texture to aid in atomization).  Then I 
advanced the ignition timing @8 degrees to get alittle more zip being the motor is in a suspended 
car. These mods did make even more horsepower but not enough to quench my
thirst for more speed. That's another story.

As far as parts this bore is a standard size Honda cr 250 bore (YEH!!) so a standard 250 piston from
 84 to 87 will work.the center square style o-ring you can get from any hardware store (home depot) 
for @ 50 cents the outer water jacket gasket I couldn't find any more so I used rtv permatex.

The head gasket is also a cr unit, base gasket is a fl250 unit As for a carb I used a 38mm mikuni round 
slide( it was the cream of the crop when I was doing the build up),  but by today's carbs I'd
probably go to a 36mm D slide for more bottom end performance while keeping top end power.
My engine came with a bassani pipe it worked well so I didn't change it, I know there are better ones that 
this now that will probably make the motor scream even more.
I also went to an fl250 cdi unit(more reliable and got tired of playing with them damn points, who ever 
designed them was a masochist).to set up a thermal push radiator set up take the hose marked exh to 
the top of the radiator and the other to the bottom.  this is if you choose not tot run some sort of a water pump.
I hope this helps you out, as soon as I can get my brothers camera i'll send some pics.
dhjunkie 

Update the engine is installed and running


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