Hi

I have done some searching around the forums, but I am still unclear, hence the new post.

I have an MC28, standard but with Tyga chambers, 2deg advance and are to order the 300kit.

Although I do have a set of PJ38s ready to go, I have been looking into boring out the standard MC28 carbs. The rationale is that this is to be a streetbike and run on high octance unleaded.

I have been offered a set of MC21 carbs with the HRC kit fitted. From what I understand, part of the HRC kit requires the removal of the power jet and changing the needles and mains accordingly?

Are the MC21 + HRC (and perhaps a bore out) a better option than MC28 carbs that have been bored - for the road. In my previous life I used to race a late model RS125 and found that although the PJ system made little difference when running avgas, it was actually usefel and made a difference when running Elf unleaded. I also had the BPS/Sabre ignition system that was complicated but great.

thanks for any advice...

cheers

Simon