Mods already done.
Head milled .030
Two rollers removed out of front
190 grams on rear clutch shoes
Milled the carb intake smooth
DG pipe

What's the boards thoughts on opening up the intake ports .5mm wider and 1mm taller and making the exhast port 1mm wider and 1.5mm taller. My thoughts is that this would allow the motor to rev higher. Loose a little torque for more rpms? On my 250r it was much more aggresive and they modded the piston skirt as well with some small holes.

 

i would say go for it

 

Your not working on a 250R. Many ppl have make the mistake of doing the same mods that are done to a big machine.
Raise and widen the exhaust. You can now take the head back and have another .010 taken off.
Widen the transfers but do not raise them.
The DG pipe is what I call a loud stock replacement. It will allow a slightly higher rpm.
Boring the carb does nothing for performance.

 

Thanks for the feedback. I'll give a report of how it turns out compared to a stock one with just 2 rollers removed and a milled head (other kids LT80) when I head out next time.

 

Got back from Glamis. I didn't raise the exhaust port, just widened it. Didn't have time to get the head milled and didn't want to lower the compression. I also widened the intake ports a little, not positive about the exact amount. But it does rev higher than before. My son is able to climb much longer/steeper dunes now. (Daughter now wants the same on hers, she's just not ready yet for anything more) Only new problem is that you must use the choke to start it, even if it has just been shut off after a long ride. Overall I'm very happy. Thanks again LT80

 

Glad it's making the kids happy.
Maybe a lil piece-o-crud got in the carb (it gets sucked in thru the vent hose that can/should have a filter on it).