totty79

If the carb has any o-rings or other rubber seals they may swell, more often than not they'll be ok in situe but will expand when taken apart and wont be easy to refit. Ethanol has a corrosive effect on brass parts like jets but it's unclear how much of a practical problem that presents. Petcock could also have a shorter life depending on its construction. If you want to take precautions then drain the carb after each use. I've seen multiple plastic tanks distort and fiberglass tanks start to dissolve, and I've also had two liners fail, some of the materials used are hard to bond to as well as not being resistant to modern fuels. Current manufacturers really shouldn't be using materials that can't handle modern fuels, they simply aren't fit for purpose. I used to work for a company that made fiberglass underground storage tanks that petrol stations use, and many cars have plastic tanks so it can be done with the right materials.

Did you check the clearance was within spec after adding shims? (0.2 to 0.8mm) The pressure plate moving immediately sounds concerning. I tried mine at 0.1mm and had to push it back to the van.

I think the ss also had a low comp head, unfortunately I've never ridden one. Some modern 300s have a really nice power delivery, some are brutal so there's no easy answer. I had a go on two shercos that were very smooth and linear, and several gas gas that were a bit lively.

My guess would be a carb float issue as that looks to be an overflow. All it could leak is fuel, but when it evaporates it will leave oil behind so it could be mistaken for an oil leak. This would also cause over fueling which would cause smoke and foul the plug.

If you replace the master cylinder the 2017 onwards one is a direct swap and has a better outer seal. It sounds like it just needs bleeding though.

Strange system with part of the top nut passing through the yoke. What is the grove around it and the bolt marks on the old one all about? It looks like the yolk may be fixed to the top nut rather than clamped between the lock nut and the top nut as you'd normally expect. Alternatively a spacer to effectively increase the thickness of the yolk may be missing.

It doesn't sound right, but I don't have a gas gas so I can't picture all of the related parts. Check the size of the bearings and any spacers and seals against the old ones and check they are seated correctly on the stem and in the headstock. As the old ones may have been incorrect also compare to the parts manual. Any thing too thick or not fully seated could make the retaining nut sit higher.

If buying one with less than a 20L capacity expect to need to carry additional water. I use a Sealey one with a 17L capacity and on a muddy day it'll get the thick of it off but it won't get it clean, this might be partly down the the pressure as well as the capacity, it's more like a hose than a pressure washer - which I guess has some advantages for bearing life.

Mine doesn't match the diagram or the photo, it has an aluminium part below the bearing that has a recess around the outside that the o ring fits in. I can only vaguely recall that the previous bearing was different and that this kit had a few alternative parts that weren't needed, I had to figure out the best combination of parts.

Fitting a low compression head would take the edge off it.

Dual purpose vehicles also have the same speed limits as cars. The odd vehicle like a caddy kombi can be found registered as a car or as a van and technically fit the definition of a dual purpose vehicle. The van derived mpv's like the ones named a couple of posts above and the caddy life are all car speed limits.

Will they let you strip it first to confirm what is needed? Seals and pistons are often common sizes so there's a good chance of finding one off an other vehicle but sizes aren't normally listed so it might take a lot of effort, you could even have a piston made if the price is right.

I can confirm these fit https://www.ebay.co.uk/itm/Ricambi-Europa-Metric-Shim-Washers-15x27-5x0-5mm-BZPY-BS06304-05-10-pack/401638850844?hash=item5d838a811c:g:4GEAAOSwqnVb8bd1 I'm currently running one of the thicker clutch plates (3mm) with the rest standard (2.65), the 1mm washer, a 0.2 shim and a 0.5 giving a clearance of 0.3mm. It was noticeably better with a 0.1 clearance, but it closed up completely when checked after a few hours riding.

With Gas Gas going through one of their financial issues at the time, Ossa having gearbox issues and nothing else really standing out I bought a 2012 Beta Evo 250 maybe 5 year ago. I've tried a few other bikes since, the nicest was a Gas Gas 300 with low comp head, but noting has made me feel like parting with the cash to replace the Evo, I'm kind of waiting for something next gen.

Thanks. Sounds like I should be able to file them out if needed.

The ratios quoted above are for synthetic oil, there is a different ratio for mineral oil but no one uses it. You'll also get more spooge if you use a high performance high burning point oil. It doesn't need to be a trials specific oil, but it's easier to buy it than to figure out the best alternative. Fork seals will be easy to find from any seal supplier, you just need to get the dimensions from the old ones.

Sorry for the lazy question, I know I could just remove the cover and measure but is it definitely 16mm ID? It lost clearance through wear so I refited one of the thicker type friction plates until the shims arrived. I bought the shims from the dimensions in the parts book which says "Shim 15.25.1" but in 0.5 thickness, I also have .2 and .3 but the od is smaller on those sizes so I'm not keen on using them.

The external return spring does not need to pull the rod clear of the piston inside the master cylinder. They never do they are too long, and seem a bit pointless. You need to ensure that the rod is not constantly pushing on the piston and preventing it from having full travel. The rear can bind if the pads are low or from dirt build up on the caliper seals as well as from issues at the master cylinder end.

The levers have to be correctly adjusted with a little slack. There's quite a bit of info on bleeding the back brake as it's not the easiest. Personally I find vacuum bleeding the easiest method.

Partly depends on storage, as some of the ageing is from uv. 6 years is the common advice for road vehicles, no idea for trials most are worn out in under a year.

I've done it a couple of times. It's just making sure the clutch has it's maximum throw by reducing the reliance on the self adjusting capability of the hydraulics. The difference can be really noticeable but isn't always, depends on what you're starting with.

I don't think this is a universal problem, for example my personal opinion is very different, I find the bike projects and repairs more interesting than much of the sporting side. Techniques threads are often interesting but results and debates on what score should have been given or which rider people support don't interest me at all.

Reduce the preload on the springs, add washers or use the top hat washers that are standard on some models, or swap out the thicker style friction plates for the thinner ones. If you change the plates then you may also need to change the shims on the release mechanism. You can also try different oil or grade of oil, but there are tons of oil threads.

I think it depends on how and when this is brought to an end, a vaccine, herd immunity or a treatment. The only option that sounds like it could be quick is an existing treatment for something else being proved effective, if that happens everything may more or less return to normal, if it takes years then a lot of society may be very different.

I followed a guide for sag which is no longer online so I can't help with that. Oil measurement differs by year, could be height or grams, but go with the manual. I guess you could keep both forks in the bottom yolk but removing them separately would be easier. Ignore the marketed oil weight, the cst value is more meaningful, match it to the oil in the manual, the weight may turn out to be 2.5w or 5w. If you get it wrong you'll run out of adjustment. Adjustment, see how max and min feels to understand the effect, set to middle and tweak as needed.