Revving problem

[unclesparks]

I took the ZXR400L1 to a local bike mechanic and he informed me of a few problems. They are
1) Cam chain and cam chain followers need replacing as tensioner full adjusted out and still slack (Rattles lots)
When a small spacer was placed in between the tensioner and followers to tighten it the rattle went and it sounded very nice so it needs do. Has anypne done this and what else should i look at whilst its apart and are the parts expansive
2) All exhaust valve clearences are tight and need adjusting but not critical
3) Carbs balanced nice and punchy up to 10000revs then it wont rev past 10K.
The bike has a MPH speedo, but engine it a L3 model. So i dont know if its a import or not. I think its restricted to 10k RPM. If so how do i derestrict it. Can you tell the difference between a uk spec loom & CDI to an import.
4) Has a slight oil leak from the from of the cyclinder block just above the area where the engine number is stamped. Is this common.
Helpa nd advice welcome and lots of it.

[RedexRobB]

Cam chain and tensioner are about 20 quid each if i remember rightly, a coupld here have done it and its not that hard either.

Shims are a close to a 5er each if you need them.

If you have a UK CDI the sticker on it should be blue, any other colour and its an import, check round the back of the clocks to see if theres a random wire floating about. You can use a UK CDI to sort it or you can buy a derestrictor box.

The oil above where the number is stamped, that at the front of the motor right? That could be the drainage holes from the spark plug recess. Theres a hole for each one to drain out oil water etc... The oil is more than likely coming from the recess stems in which case you can simply take the rocker cover off pull them up and replace with new seals, or for a quick fix use blue hermatite

[unclesparks]

Sticker on CDI is yellow/gold in colour. On my old NC30 the UK spec CDI had an extra wire over the import CDI. I take it a uk spec CDI should plug straight im without anyother modifications?

[RedexRobB]

mine is yellow and is an import. Yes the UK CDI is a straight swap, has a better ignition curve too and also gives you an extra 400rpm apparently.