I found the idle screw on the left side of the MC21 under the tank but it doesn't matter which way I turn it never seems to get to a point where it stops...is that right?

I have a funny feeling its come loose from the carbs, if that can happen but I can't check as it's pitch black outside.

Any assistance would be greatly appreciated.

Well that was a midnight mission!

Took a torch out, tank off, carbs off and sure enough the idle screw was not attached. Found a little spring, washer and small bracket so put it all back together.

It started but after a few seconds the revs started to climb, when it got near 5k I cut the engine. Will have to investigate this further tomorrrow as I tried to start it again and it wouldn't have it.

Just took the plugs off and they are as black as you can get, running very rich so its probably flooding.

I think the reason the revs are climbing is because I haven't seated the carbs in the manifolds correctly as it was too dark to see what I was doing properly.

Will sort this all out tomorrow and may mod the airbox to lean it out a bit.

Might be a good idea to get it running right before chopping the airbox up? Have you had the carbs off and cleaned them? Checked the float levels? Balanced the carbs? If you have a search on here, there have been other users with the same rizing rev's problem, and these have been some of the solutions. Could be rich because of the float not set right? New plugs I assume? If its got standard jets in it and nothings been touched engine or pipe wise it should caburate pretty well, honda got them pretty well dialled. One symtom of rising revs is an air leak, like you said, the carbs might not be seated correctly, or it could be crank seals, especially if it has sat for a while. I know Dubai is dry and all but still.............
Just my 2 cents worth, but that's where I would start before cutting away and potentially masking (or creating) another problem.

The rising rev thing only happened after I took the carbs off so it must be that I put them on incorrectly.

It started after about 5 kicks when I started it for the first time and ran fine but I start fiddling with the idle which is when it all went pear shape, especially when the idle screw fell off!

It's totally stock. Put new plugs on it last night. Will play some more when I get home from work. I will need to clean the carbs though I think.

Finally sorted the over reving & hard to start problem.

Turns out when I had the carbs off I didn't seat them correctly into the airbox so there was an air leak. Also, I kinked the fuel tank breather hose and one of the carb breather hoses.

Video below.

http://youtu.be/tXSbX0spgDE

Its running very rich, probably wasn't in Japan but here in Dubai it is...you can hear the bogging as I open the throttle and it doesn't want to be ridden at all, as soon as I release the clutch in first gear the revs drop...needs some fine tuning which I'll have to do at the weekend.

it is the weekend
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if dont fall off every now and then your not trying hard enough

chucky wrote:it is the weekend

Not for me here in Dubai...weekend is Friday/Saturday not Saturday/Sunday so mine is over, started work this morning.

fair enough

My bike is obviously very rich from plug colour and bogging...Should I buy smaller jets or will I get the same effect by drilling 4 x 20mm holes in the front slope of the airbox?

I'd go with jets after you've drilled the airbox lid,as the extra air flow can also draw more fuel!
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it wouldn't be fun if it was easy!

check the jets first see if thjey are a standard size

Will get the carbs off tomorrow...again Will give them a good clean whilst they're off.

Any place you guys recommend to buy jets?

you have never raced a 2 stroke each time you ride it you take the carbs off

and the barrels every day which means the pipes too, and the wheels alot