Fix pro50z dirt bike

There are a few problems with the Crusty Deamons pro50z pit bike

Some kind of carbie problem (I assume) that makes it hard to start.
The gear change leaver has a damaged spline and thread
The clutch is jammed in the engaged position.

And of course I know next to nothing about small chinese motor bikes.
We are going to start with the clutch.
To that end I have searched the net and not had success in locating photos or an exploded view.
I have posted a question here:


http://www.miniriders.com/chinese-minis/36849-pro50z.html

This is the bike.  Friends may recall Chris rode it into the back of Paul & Cybele's car a few years back.

This is with the cover plate removed.  When you pull the clutch leaver on the handle bars, the cable moves toward the top of the picture.  This makes the shaft turn and then the black bolt in the middle of the picture moves outward.







My plan, unless someone gives me a better idea is to
1.  Drain the oil from the crank case.
2.  Undo the bolts that hold the chrome casing on
3.  Hope that noting falls out before I get to see where to put it back in.

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2-OCT-2012 UPDATE
I left for work and gave Dan instructions top drain the oil and remove the covers.
Here are the photos.
We concluded that the clutch is probably OK.

There are 4 bolt lengths

This picture shows where 1,2 & 3 go.  All the rest are size 4











The clutch housing cover pulls off over the kick starter shaft.

Remove the kick starter and don't loose the bolt.  (Put it back in the kick starter for later).

The foot rest prevented the clutch housing cover from being removed.

Remove the foot rests and stand assembly.  It's bolted to the crank case with 4 bolts.

We had to lean the bike against the table because the stand was being removed.

Foot rests and stand assembly -
The short bolts go toward the back of the bike.

This disappointing out of focus photo shows the clutch.  It looks like some kind of brake shoe type clutch.  You can see the 4 springs.

This doodad pushed against the bearing in the centre of the clutch (see pics above and below) and disengages the clutch.

This little thing popped out.  Dunno what it does.  Maybe some kind person can leave a comment.

It was not rusty and I was not game to dismantle it any further.  Suspect that we are just not pulling on the cable hard enough.

Incidentally on the other side we see the magneto.

And the chain tensioner - not tensioning.  Another thing to fix!






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The Gear changer had slipped around the shaft and the kids had used a pair of vice grips as a gear changer and wrecked the spline.

The thread in the gear changer was stripped.  So we put in a longer bolt and added a nut (can't see) and tightened it up unit it gave.  Well the gear changer cracked.  I am not sure if this is the original gear changer or another used one I had lying around.  Anyway it's now cracked!.  Blast!


these chinese engines seem to use parts from a Honda C90 engine.






This link points to a page with an exploded view of the clutch assembly.
http://www.hondatrailbikes.com/catalog/performance.php
Quote:
"If the clutch nut is not torqued on, it will result in knocking, spline damage etc. Please do not try to tighten the clutch nut with a hammer and screwdriver – use a clutch nut socket."