MOPED ARMY

I'll give you a short how-to:

Whe you get the new kit, it will consist of a couple of parts:

Cilinder

Piston

Piston ring(s)

Small-end "bolt" and sometimes a bearing

2 circlips

Gaskets

Sometimes a head

To properly install this, do as follows:

Mount the piston to the small-end with the bearing and close it with the 2 circlips. Have the arrow point down, to the exhaust port.

Now put a base gasket onto the cilinder.

Grease up the cilinder wall with a little bit of 2-stroke oil. Do the same for the piston. Get all the surface covered with a thin film of oil.

Put the piston ring(s) on the piston. Mind the little nodges in the piston, or the rings won't fit.

Compress the first piston ring between your thumb and index finder and slide the cilinder, on the mountingstuds, over the piston. If you have a second ring, do the same for that.

If the 2 rings are in the cilinder, you can now "mount" the cilinder by pressing it softly against the engine.

Apply some pressure to the top of the cilinder and turn your flywheel to see the deckheight. If it is too little, (IE. the piston gets higher than the cilinder wall) add another base gasket.

If all looks well you can put a head gasket on and mount the head.

Tighten the bolts crosswise. IE. If you number the bolts clockwise

1 2

3 4

Start with 1 and tighten till you feel just a hint of resistance and then go to 3, do the same, then 2 and then 4.

Then tighten em all the way in the same order.

Now don't get excited, you're not done yet!

Turn the flywheel slowly, by hand, to get atleast a few full strokes. Make sure the piston doesn't touch the head. If it does, add another base gasket. Never add another head gasket, this will mess up your compression and it'll soon start to leak.

If all is well, upjet if you come from a 50cc add a spark plug and then start the engine. After starting, let it idle for about 2 minutes and then turn it off.

1 last check: When then engine is warm after 2 minutes of idling, turn the flywheel by hand and see if it is still smooth. If it hits the head, again: Add another base gasket. (About 3 basegaskets is the maximum. There are special thick gaskets for sale.

That's it. You're done.

For breaking it in: Add some extra oil to your fuel (About 1:40) and take it easy for the first 20 minutes. No full throttle or high revs. After 20 minutes you can make more revs. Making high revs while breaking in is not bad. As long as the cilinder is nice and warm and you remember not to keep the same RPM for more then a minute.

i reccomend 32:1 and use non synthetic oil until broken in.

People say 300 miles or three gas tanks full.

And I say let it idle for ten mins before riding it.

I agree. Remember that most of our engines are air-cooled with the exception of the Minarelli and a few fancy liquid-cooled Moby's, if no air is rushing past the cooling fins you'll overheat the engine for sure especially if it's something like ten minutes. I'm riding at night now with temperatures hovering around 12degrees Celcius and I don't let it idle for longer than 2 minutes.

I've never heard of the bump you're speaking off though, how does it form?

I was taught, from a crusty old 2 stroke snowmobile tuner, to put a house fan on the top end, blowing air over it, and let it idle for a few minutes, giving it a little burp of the throttle every so often.

usually works pretty well

Because your piston stretches higher at high rpm (Centrifugal force) it reaches the top of the cilinder wall. It won't reach that at idle.

The cilinderwall has a crossed pattern from the factory, to allow the piston and wall to smooth into each other. This leaves a little excess metal, and if you don't get the piston at the top of the cilinder while this is scraping off, it'll form a bump a lil under it. And when you do rev it up, your piston will encounter a lil bump.

Most of the time it isn't really harmful, but it could seize because of it.

I did 32:1 and let it warm up for about 3 minutes. I started up on the first kick which was really surprising. I'll be keeping it 25 and under for the first 150 miles or so. I did notice that when I hit around 20mph and let off the throttle it would have a high pitch ringing sound as it spooled down. Is this normal?

I agree with the fan idea but you need something a little more...portable. I had some 12volt computer fans pumping air on my engine for a while last year, I'd turn it on at length stop lights are if I stopped at a store for a few minutes. Took it off because the controls kept getting vandalized by some punks.