d2w

Perhaps here: https://www.trialsbikebreakersuk.com/ Or try Jim Snell in the USA here: http://www.trialspartsusa.com/repair-services.html

Howdy. I believe the VMar units are still available. Dunno about the one made on your side of the pond. But here's a quick/no cost solution to try first. Release the carb from the reed block. Secure it well to the airbox outlet (aka the snorkel) Use a hot air gun (>>> not an open flame!!! <<<) to soften the snorkel material. Heat it from all sides uniformly. When it's sufficiently pliable, push the carb into the reed block and secure.Let it cool and - voila - it should be "back to normal". For an even "better" seal, I secure my rubber adapter to the carb using an adhesive called "Shoe Goo". It's some sort of vinyl adhesive.

Hmmm ... it sure sounds like something is amiss internal to your transmission; it shouldn't spontaneously shift on its own! I'm repairing the internals of the transmission on my 2008 TXT300 PRO, and if the designs of the transmissions of our two bikes are similar, I certainly can imagine how my issue - a broken circlip on one of the transmission gear shafts (which allowed the gear to "float" and effectively shift) - could be the root cause of what you're experiencing as well. The fix necessitates splitting the cases. There is a Jim Snell video which details the rebuilding on your vintage of engine. Is there any "shrapnel" on the oil drain plug magnet? My circlip - actually, half of it! - was firmly attached. No question about whether to split the cases when I saw that.

And there's a trick to using the puller tool correctly. After you've ensured that all threads are clean, thread the outer piece into the flywheel. Once you've bottomed-out, thread the inner piece into the outer. Snug the inner piece to the crank. Tighten but only until solid. Then hit the flywheel with a (hopefully soft, maybe copper (?)) mallet. Then tighten the inner piece and repeat. The idea is to use the puller to provide a constant force trying to separate the flywheel from the crank, but it's the shock of the mallet which dislodges the flywheel from the crank. You need the sudden shock/force to break the flywheel free from the tapered crank. OK ... me bad ... I just finished removing my flywheel to begin to service a tranny shifting issue and the >real< trick is to hit the puller bolt head with a hammer and NOT the flywheel. 👍

While the radiator/fan is out, drill-out the rivets which secure the fan to the rad and replace with short sheet-metal screws. Then in the future you can remove the fan (say to replace the fan motor ) or to ease access to the top-end without having to remove the radiator itself.

This is likely equivalent to the OEM unit in your GG: https://www.splatshop.co.uk/xiu-rdi-adjustable-spring-clutch-support-plate.html

While you're poking about, verify that your rotor isn't below it's minimum thickness; if it's too thin it's possible the pistons are over-extending and not applying an even pressure onto the pads.

I too have Marzocchi forks on one of my TXTs, and parts for those forks are difficult to source. I've heard others have had some success finding equivalent parts at pedal-bike shops as Marzocchi forks are/were used on some high-end mountain bikes. Try the Trials Bike Breaker in the UK. Ohlins seems to offer a good supply of parts for their products, and you might be able to source an equivalent part from them. Oh, yes, the paint covered springs are after-market and are clearly a bad design; OEM springs are unpainted.

If you need a smidge more of clearance, consider using a metal gasket between the engine and the flywheel cover; the later bikes used these thicker gaskets. The Splat Shop has them. The SS can also sell you a new flywheel cover for not much coin.

With full credit to the Hell Team. Follow the link at the bottom of their page for the detailed instrucitons. https://thehellteam.blog/servicing-marzocchi-40mm-aluminium-forks/

In addition to what peterb suggests, use a heat-gun/hair-drier to warm and soften the rubber between the carb and the airbox before pushing the carb outlet into the reed-block input. Basically you're trying to stretch the rubber snorkel.

Some related thoughts on the various matters gleaned from my experience with my - albeit older - 2008 GG TXT 300 PRO: - The "put it in gear (2nd), roll back to find compression, pull in the clutch, press lightly on the kick starter until resistance is felt, and then kick solidly" is the required starting procedure. - I just added the S3 head and low compression insert and it feels very nice. Oddly enough the inserts and head required a minor modification in order to get them to fit; you had to pull/grind the alignment pin in the insert otherwise the two pieces WON'T align. - Use some grease to hold the head o-rings in place when reassembling; the grease prevents them from dropping out and becoming pinched. - I also fitted a flywheel weight to my bike (to further smooth it). - Some people fit the throttle with the black tube for a slower/longer response (but I prefer the faster white tube). Enjoy.

Yes. Crank case breather. Normally there's an elbow in the hole, and then a hose which runs up into the steering head area.

OK, here are some photos. The first shows the ignition module (left) and coil (right), The second shows the voltage regulator (top, in the crescent cutout). And the third shows the fan control module (with the 'E') mounted to the fan shroud.

No worries. I can send some photos is you need more info. And note that it's possible that the actual wiring may be different than what's depicted in the schematic; in my bikes the rad thermostat is positioned between the fan controller and the fan. Hmmm ... this is actually less than optimal as the fan controller will always be powered. It might be better to ensure that the actual wiring is as the schematic shows.

On my 2008s, the (Kokusan) CDI mounts under a wire tab on the left side of the frame near the steering stem.The coil mounts via a bolt into a threaded insert on the right side of the frame near the steering stem (near the rad cap). The voltage regulator mounts low in the area of the steering stem. And the fan controller mounts on the upper/left corner of the fan shroud. It's all a tight fit. Yes, the rocker switch is for the dual-mapping of the CDI. This may help:

This is another alternative. https://trialendurodirect.com/product/gg-pro-model-cylinder-head-spacer/ I'm not sure if it's compatible with the head of your 2020 model. It worked well on my son's 2008. But it's not without issues: - There's no o-rings between the top of the cylinder and the plate, so you have to seal it with silicon/gasket maker, and that could leak. - You increase the squish band by 1mm, so that may effect your engine running (but we did not experience that). But it is a low-cost option which can easily be jettisoned if it doesn't work for you.

Not without cost, but I believe a 250cc or 280cc cylinder and piston can be fitted on a 300cc engine; they share the same crank case.

Further to jonboy883's post, if the water pump seal is compromised then the crankcase oil will be white/milky (in addition to the coolant level being down). If you replace the seal then you should also replace the pump shaft as the seal rides on the pump shaft and wears it.

I believe it's possible that the white "smoke" could in fact be steam, and this results when coolant gets by the head o-rings and enters the combustion chamber. Is your coolant level down? Pop the head and have a look around. Or remove the header pipe and view the top of the piston via the exhaust port.

Suggest you watch what's posted from the Trials Bike Breakers (and they're on your side of the pond ?)

Oh, and another obvious check ... verify that the radiator fins are not plugged/obstructed (say by dirt/dried mud). It's all a pretty simple system, but it's no less critical for the correct operation of your bike.

Or perhaps the fan is on because the bike is too hot (regardless of the air temperature)? Have you verified the amount and state of the coolant? Have you checked the water pump (as I've heard that the impeller blades can deteriorate)? Have you inspected the coolant channels in the cylinder (perhaps they're partially blocked)?

As unpleasant as it may seem, I do believe that what you (mostly) describe is normal; I know that both of my 2008 GGs require "effort" to shift between 4th and 5th. I believe the effort is required because the compact design of the transmission requires that two sets of gears move when shifting between 4th and 5th, and there's just more moving parts which need to come together when making this transition. My 4th to 5th issue can be mitigated by realizing that my tranny can never be "flicked" between those gears, and instead if I hold the lever (in 5th) before and during when I release the clutch when up-shifting things go better. Same with 4th; hold in 4th and then release the clutch when down-shifting. I guess, basically try different shifting techniques. But a grinding sound doesn't sound good. Have you ensured that you have correct free-play on your clutch? Are you getting a good disengagement?

My son had a TXT50, and I seem to recall that it had a dual-function clutch arrangement; is there a clutch lever as well as an automatic clutch mechanism? On my son's bike I removed the clutch lever and replaced it with a rear brake (and removed the rear brake pedal). This was done to be an easier transition from his OSET which had its controls setup that way. Perhaps your clutch level mechanism is preventing the automatic clutch from fully engaging? And don't expect the TXT50 to do big walls and splats. Use it to teach the basics and how to start a gas motor, how not to get burnt, etc. Clutch control too. And start shopping for the next bike right now. I went with a GG TXT80 but it too was so down on power; but still a good platform to learn gear selection, etc. I have no experience with it but I've heard good things about the Beta Rev80 with the big wheels. Have fun.