tony27

The photos of the broken selector, does anything look different to your's? Before getting further into the motor I would be refitting the gear change shaft & operating the lever while watching what goes on at the indexing plate, you will probably need to spin the rear wheel or fit the clutch holding nut to the end of the shaft & use it to turn the gearbox If the shifting side is working properly you will see the spring loaded roller drop into the next recess around I guess it is possible that the pin in the end of the selector drum has broken so the cam isn't moving it properly, easy to check by removing the capscrew in the centre of the indexing plate & taking off the plate. Have a look at the photo of the selector drum in the link above by clicking it & you'll see what the end looks like I was hoping 1 of the guys from Splatshop may have been in here by now, they're definitely worth asking what they think is the problem

If I can find the parts I'll show you where the engineered in weak spot is, basically the mechanism that grabs the pins on the end of the drum is only welded on the 1 side & the shaft is turned down quite a bit. I snapped the shaft on my first Bultaco branded Sherco & have twisted at least 1 other. When you twist the shaft at the weak point the lever hits the bashplate so getting first gear is a problem, can't remember if it affected changing down but I expect so, haven't had a problem since I fitted the short type lever

Remove the primary cover, slide the spring loaded piece back so it clears the drum & it slides out. From what I can see both springs I mentioned are still in place but I would still be checking everything in that area. Make sure all the pins on the end of the drum are still good & the capscrew is tight

Could be something as simple as the spring in the selector mechanism. Remove the clutch & primary cover to check the condition of the spring fitted inside the mechanism on the end of the gearchange shaft, part number is M111. The other spring to check is the 1 that keeps pressure on the indexing cam, part number M117 Both of these parts are outside of the gearbox & easy to check once the clutch is off, both are only a couple of quid Sherco gearchange shafts have a weak point built into them that lets them break rather than damage internal parts so I'd be pretty confident that a full motor split will not be required Have a look at this diagram & both springs I mention are on the left http://www.splatshop.co.uk/Parts-Finder/Sherco/2009/290/Gear-Selector/

Does the TK carb fitted have the main jet screwed into the float bowl like I suspect, if so replace the o-ring that sits on the bottom of the needle jet as if it is damaged it lets fuel bypass the main jet & it will run very rich

Is this what you want? http://www.tyoffroad.co.uk/store/p85/SHOCK_ABSORBER_LOWERING_KIT_TO_FIT_YAMAHA_TY175_TY125_TY200_TY220._(REF.051).html

I wonder if it's something to do with front is easier to hit on things & by floating is less likely to bend?

Fit oversize linings turned to the same diameter as the drum, you get full contact that way so they'll be as good as possible

From what I can see your woodruff key was 3/4 sheared rather than made that way. Just refit the stator in the same position that it was in, looks like centre of the slot going on the witness marks from the washers Should be pretty close to right

For seals & other parts Thor Lawson in the states is the man to use. I bought the parts & manual off him when I rebuilt mine but rather than buy the internal bush I made new ones out of aluminium bronze that I had left over from a job at work http://evolutionsuspensionproducts.com/ThorLawson/index.html

Not the most blatant example caught on video either, there is 1 where Bou backs up right beside the observer with a foot down then his minder is further along the section emptying the whole bottle onto a couple of rocks. Looked to still get given a clean

In 1 of the videos I've seen he backed up with a foot down a few bike lengths into the section & got away with it, it was 1 of the sections that towards the end his minder is very blatantly washing the rocks. A farce probably isn't a strong enough description of what I think of the whole situation

Must have been missing something as the bearing should be shorter than the sleeve around the shaft

There are 2 or 3 different swingarm extension plates available, 1 type involves cutting the swingarm plate off at approximately 45 degrees the same amount both sides & welding the new parts on. The ones shedworks sell should lengthen the swingarm 40mm or so. The other type I've seen on eBay involve cutting the end of the axle slot off & sliding the new part in for welding which should be easier to get the axle slots perfectly inline. These ones may give slightly more length

I'm wondering if top friction plate is in wrong place or pressure plate not lined up with the marks on the hub. Been a while since I've been inside my motor, push rod is turned down both ends to different lengths going off photo on Splatshop's site, could be in backwards with the shorter length at the clutch end

Have you tried different oil heights? Lower the level by 10mm & see if it helps

Anytime you see a level quoted it will be with the fork compressed & no spring, rod should be extended as well

Self tapping screw wound in gently then pulled out with vice grips. Don't wind it in too far or you risk damaging the bearing

Engine number should be above the swingarm pivot

Shouldn't need to double up on gaskets, I think that was a much later bike that had different thickness gaskets to alter squish gap to the head & also port height I've always removed head & cylinder in 1 piece rather than needing to replace the o-rings between the 2. Fitting the cylinder over the rings isn't hard but that is all down to making sure the gaps are centred over the locating pins before you start. Use something under the piston to hold it steady then lower the cylinder over the piston while pressing in on the rings through the gap in the transfer ports, you can twist the cylinder a small amount to make the rings sit around the locating pins if needed, compress the lower ring the same way & the cylinder should slide down to whatever you used to stop the piston rocking

To play devils advocate here, what difference is there between these Honda copy motors & using a replica frame, neither is truely period & replicas rarely are 100% copies of the original

Unfortunately Beta uses different hubs to the other manufacturers, as you've found the widths & spacing of sprocket & disc are different. Most of the other manufacturers share hubs & the rear wheels especially swap over It's likely that as well as spacing the sprocket & disc the correct amounts which also need to be relative to the rim centreline/edge you would also need to make spacers to centre the wheel in the swingarm Could be a lot of work that won't be as strong as the original parts due to longer bolts & the sprocket & disc no longer located on the inside to the hub casting

If you look at the top slot there should be a line punched on the stator, rather than retarding the ignition I would line that up with the edge of the casting which is standard position & see how it goes. Mark looks a long way from where it should be The earlier ignition covers with built-in sprocket cover never sealed right, they distort basically right in front of the sprocket & throw chain flings water through the gap. I changed to the 06 on cover as soon as they became available & haven’t had a problem since, use sealant instead of the original o-ring to maximise benefit

If you didn't get the motor hot enough to dry the exhaust out properly after submerging it chances are you're going to need main bearings soon. Is the play in/out with the primary gear off or up/down? Up/down is worn out, the primary gear being tightened up should remove in/out play Replacing main bearings isn't the worst job as long as you take your time, biggest thing to be careful of is the gearbox. The whole job is in 1 of the links pinned at the top of the section

Very nice, are both running standard porting? I have a V-Force reed block to fit into my C model but haven't had a chance to get inside the cylinder to open the intake housing out for it to fit. Do you credit the reed with the wider power spread?