Here we go again, Andy will have kittens when he sees this thread!

NSRLOVER has an mc21!

MC18 and MC21, stock mj is a 128
MC28 stock mj is a 140

Premix is 3% which is about one jet size up.

200 mj's will be open carbs and no power jets.

That's the big bit, NO POWER JETS!

Specific jetting advice is banned in the general section but this is so general I'm happy to say the 200mj's and power jets on any NSR will be too rich!

The rear hed conversion puts the plug more central in the combustion chamber, it doesn't make a noticeable gain on it's own, you'll also need the shorty plug and cap unless you want to wear you plug cap down with the front wheel under braking.
It's an easy job though and a must if you're chasing max power as the front head plug position is rubbish.
_________________
Please do not PM me technical questions, if you can't find it on the Forum start a thread