d2w

The pedal is an Al-alloy while the shaft is some sort of harder steel; use a torch or heatgun to heat the pedal and hopefully it will expand enough to free itself from the shaft. Perhaps the previous owner Locktite'd the pedal onto the shaft? If so the heat will help to free the adhesive.

Doesn't sound correct. But consider placing some o-rings on the shaft between the pedal and the seal to help keep the seal pushed into the case.

Can't agree more that you should completely dismantle the rear suspension and verify the state of all bearings, and then lube them. If your bike was put away "wet", the rust will have had a nice long time to form. Not good. Steering head and wheel bearings too. If for no other reason, do it for your peace of mind.

There's no "right" or "wrong" position, but the two forks/folks need to be equal. Sliding the forks up the triple clamp will slightly increase the rake and make the bike turn a wee bit "faster" (but be a bit more "twitchy" when trying to go straight). And the converse is true when the forks are pushed down the triple clamps. I believe the top of the fork >tubes< should never be lower than the top of the triple clamp.

Thank you for that critical bit of knowledge. I found this related useful thread: https://www.trialscentral.com/forums/topic/57493-crank-bearings/

Hmmm ... I'm just trying to learn from this thread (and not de-rail it). Doesn't the LHS oil seal actually keep the crank and flywheel/stator areas separate? Neither of those areas contain liquid oil. So if there was a leak wouldn't it be an air leak? And then wouldn't that cause the bike to run lean (with the added air into the crank) or just poorly (with less vacuum to draw in the fuel/air mixture)? And isn't it the RHS oil seal which separates the crank from the oil within the clutch/transmission? I could imagine a leak in that seal would draw oil into the crank and colour the exhaust as the oil would be combusted. Thanks for the education.

A fun-looking project. Consider that you may have parts from more than one bike there; it appears that you have four or five brake slave cylinders, and you'll only need two.

For future reference, from whom did you buy it (if not a private sale)?

Could the white smoke be in fact steam? I seem to recall reading that white "smoke" could be indicative of a head (o-ring) leak into the combustion chamber. Perhaps do a quick assessment of your coolant level?

Three suggestions: 1) Search this forum as "Can't get pressure on the clutch" is a question/issue often raised. 2) Use your syringe to push fluid from the slave back/up to the master. 3) Verify that the plunger on the master is moving to the outer (c-clip) stop and that you're getting the full range of motion. You need to ensure that you're moving the seal so that the orifice to the hose is exposed, otherwise the line will never pressurize when the lever is squeezed. Be methodical in your debugging; there are not a lot of pieces to the puzzle.

I don't know what clearances your bike has between the existing flywheel and the flywheel/magneto/stator cover, but with the help of my brother we machined a band of metal rather than a disc for use in my son's TXT80. We heated the band and cooled the existing flywheel for installation, and when the metals returned to their normal temps they were held together tight.For metal we purchased some brass pipe whose ID was slightly smaller than the OD of the existing flywheel, then we machined the ID, the OD and the width. We used a blob of modeling clay (Plasticine, Playdoh, etc.) stuck to the flywheel to determine what clearances we had to work with; stick the clay to the flywheel, temporarily refit the cover, spin the engine to move the flywheel/clay through a rotation, and then remove the cover. Voila, the thickness of the clay will match the maximum thickness of your flywheel weight. Note, mounting a band of metal on the outer diameter of the existing flywheel will be significantly more effective then mounting a disk on the plane of the flywheel.As a result the weight can be less than what would normally be considered in much an application. Good luck. FYI, the FWW didn't do much for the TXT80; it did help with the inertia and made the bike easier to ride, but it did slow down the engine response. In the end I concluded that the little 80cc just wasn't going to deliver the performance my son needed, and so I got him a TXT280! He's happy now.

I suggest that you also verify that the piston is installed in the correct orientation; you want it so that the ring retaining pins (and hence the ring ends) do not pass any port openings in the cylinder (where they might catch). Normally, a piston will have a mark (typically a "V") stamped on the crown, and that's to be oriented towards the exhaust port. I can see an "A" on your piston which corresponds to the size (first oversize), but I don't clearly see the "V". Or maybe the "V" is there amongst the other lines/marks. Just have a look. I will be obvious when you remove the jug as to whether or not the piston is installed correctly; you want the ring ends towards the rear-half of the jug,

I suggest checking the easiest and obvious before wrenching the engine: - Air flow not impeded? Air box, filter, connecting junctions. - Fuel available? Flowing from tank to carb? Correct mixture ratio? - Got spark? Clean or fouled plug? - Do you have compression? Reduced compression? - Not that it's directly power/performance related, but do you have sufficient coolant? Is your oil clean (and coolant free)? But running with little/no coolant can eventually toast your engine due to excessive heat.

The difficulty we experienced - and it may have very well been due to our poor riding/teaching technique - was that the TXT 70 motor - a Morenelli I believe - was essentially a scooter motor and had no torque. So to use the bike Even really had to ring it out into its 10K RPM range! But this is not where one wants to be when learning. I did make a flywheel and I did replace the jug and piston - again looking for more power -, but the changes weren't significant. And now on the 280 the opposite problem is occurring as Evan struggles to keep the front wheel on the ground.

I have owned a TXT 50 Rookie and a TXT 70 Cadet and they are very different engines (and transmissions); the Rookie had a two-speed gearbox with a manual as well as an automatic clutch, while the Cadet had a six-speed manual clutch. I started my son on an OSET and transitioned through the Rookie and Cadet, but it's now on the TXT 280 that he's finally making significant progress and having fun. And it helps for him that at only 13 years old he's already 6 foot 1 inch! The power of the bike and the full sized wheels make all the difference for him. Still, having the smaller bikes were fun and built his confidence, but I too tried to "find more power" from them and it just didn't work. If I were to do it all over again rather than the Rookie and Cadet I might go with some of the bigger OSETs before getting a full-sized gas bike. The 280 was selected because it was available/close and shares most of its parts with my TXT300. A 125 or a Beta 200 might be a better first gas trials if coming off of a series of electrics.

Yup. Simple friction fit. I use a nylon/rubber hammer to gently tap mine into place. I guess one could use some sort of adhesive (silicon perhaps) to glue it into place.

Alexdukes ... Just some basic questions ... What do you see in the oil when you drain it? What kind/size of debris is stuck to the fill and drain plug magnets? I believe that diesel fuel is a safe solution to use when trying to flush debris from an engine.

I'm sorry for Alexdukes situation, but I'm eager to learn from it as well. If a (connecting road and/or main) bearing "went", how would one assess that? What would you "feel" when moving the crank through its stroke? Would it grind or stick or ... ?

I too noted that texturing around the the piston top (but not on the top of the crown). Would that area correspond to the "squish zone" (and so little clearance between the head and the piston)? It sure looks like something was being driven into the piston. Alexdukes ... Do you have a picture of the (underside of the) head?

I'm having similar issues with the boots on my older GG's. Thumbs-up to Lineaway's suggestion. In addition I may try to somehow soften the rubber; I was thinking of leaving it near a source of moderate heat (possibly steam from a boiling kettle, or a hairdryer). An open flame or too high a heat or a concentrated heat could be bad.Good luck.

Well, there's only four major components in the system; the rear brake caliper/slave cylinder, the hose, the master cylinder, and the reservoir. As you speculate, there must be a blockage in at least one of those items. Time to dismantle and test each for flow. My money is on a stuck piston in the master cylinder (or one that;s not retracting sufficiently to expose the refill hole). Good luck and keep us informed of your findings.

A slight - but related - diversion ... on two occasions I've snapped a seized brake bleeder nipple The nipple is hollow and I'm guessing the dissimilar metals of the nipple and caliper set up some sort of galvanic reaction and/or oxidization which effectively glues the two parts together. I tried to use heat to free them first but it never worked. But once broken off I was able to carefully use a hand drill to remove the broken bits and retap using an M6x1 (I think). So long as you don't go too deep on the final/largest drill bit you can preserve the seating surface and the new nipple will seal. I then use some Teflon "plumber tape" on the threads to better secure the nipple and ensure easy removal the next time. Don't forget to pierce a hole in the tape to allow the fluid to drain when the nipple is partially backed out.

An even easier procedure is to fill the syringe with brake fluid and inject it into the rear brake bleeder nipple. This will force the fluid through the entire system. The fluid will then accumulate in the reservoir. Note that if you can't force fluid into the system it may be due to there not being sufficient flee play in the pedal/master cylinder; there's a hole to the reservoir which is exposed when the pedal is at rest and this allows the circuit to refill. When you apply force to the pedal the piston moves and covers the hole and pressurizes the fluid which causes the slave pistons to expand and apply the brakes. Sorry ... I just reread your original post and you mention that you tried to backbleed the system but it didn't work. It sounds like your return path to the reservoir is blocked. Again, check for the freeplay in the pedal/master cylinder.

Just where are you touching the HT lead? If you're touching an insulated section then no problem. If you're touching the exposed conductor and you're also touching the return path to the HT circuit then you should experience a helluva jolt. But what you're experiencing is likely the pickiness of the GG starting ritual. Search this forum as we've all experienced your current frustration. The quick fix/suggestion is to: Put the bike into 2nd gear. Clutch out. Roll backwards until the compression stops you. Clutch in. Apply light pressure to the kick starter until it just stops. Then kick hard. If the choke is engaged then don't touch the throttle until it's sparked. If it's already warm you may need to twist the throttle while kicking. If you attempt to fan the kick starter repeatedly like an enduro you're going to experience a heap of hurt in your wallet as you damage the starter gear mechanism. Also ensure that you're jetting is correct. Good gas. Clean carb. Fresh plug. The usual suspects. I can spark my GG in one kick when warm. Two maximum if cold.

I acknowledge that I'm not the original poster (bikerpet) but I'm interested in this repair. What (major) wrenching operations are required when replacing #10? When replacing the entire shaft? Can one do the work after only removing the clutch cover and clutch/basket, or does the case have to be split (after removing the engine from the frame, then removing the cylinder, et al)? Can the shaft seal (#5) be reused or does removing the shaft damage the seal? Thanks.