miner

Could be... worth a try...

3.5 turns out the norm then? Would 2 be leaner? First run out after rebuilding the carb... bike felt a little flat at initial opening... maybe a little lean?

Catching up with this one... new gasket in, S3 kit o-rings didn’t fit, couldn’t get a viton 78x1.76 locally, ordered from splatshop... still no joy. Put old o-rings back in. ??‍♂️ Rebuilt the carb, so many small pieces missing... all rest hard and perished... starts and runs better than it ever has. No leaks... clutch out it sounds like a bag of spanners but all good, it was like that anyway. Running a treat. Got new grips and levers... fit them through the week. (Mrs was working - had to take the dogs to the beach and debrief 5 loads of washing ?). Took it for a spin... happy days, missed it so much. Wasn’t too rusty as been out at the track twice and off-road twice in as many weeks... but forgot how much it can fly... didn’t loop it but survived a few surprise take offs!?? Can’t wait for next weekend now... ?

So to wrap up... after a good night’s sleep and not being massively hungover... I decided to raid the shed and found an old set of Allen keys... was enough as get a decent grip on it, used a spanner on the end to tighten it, then snapped the mole grips onto it to do the final tighten up (calibrated nip up). Dunno if it’s 30Nm but it felt pretty feckin tight and nice and even. Took it out for a blast... came back, had Chinese curry and beer... away to blow dry her and put her to bed. ??

I had the same thing recently... bike is an 07 and the base gasket disintegrated so was wondering what to do with it... two stroke enduro bikes had me paranoid. Took the barrel off to do the work and inspected the piston, bore, etc... ring gap was 0.4mm which is the wear limit for my 200 EXC, 250 is bigger bore so left it in. Piston and barrel look ok, bike runs ok. Best thing like the guys said... tear it all down and check it out, rebuild with fresh gaskets and go again.

Could be onto something there...

What’s the best tooling to access this? The gasket kit GG sent came with two cap head Allen bolts instead of two button head ones... looks more robust and less prone to rounding... which is useful as the bottom bolt is certain to get rounded at some stage. Not sure if it’s just my cheaper tools aren’t delicate enough as get decent access even with the universal joint... but FML... what a poorly thought out routing. Thoughts and feedback from past GG maintenance Tourette’s welcome... ?

Great video cascao, just watched that there... still missing a washer for the mixture screw... not sure what I’ve got kicking about either. Wasn’t sure if it was still jammed in there with the old o-ring... will have another look. Didn’t realise there was mean to be a washer under the needle clip either... new one to me, no loose parts in there on the Keihin’s. Get this bike together yet...

Found a full exploded diagram... one to go under the float jet and a washer to make do between the spring and the o-ring on the mixture screw. Cap still doesn’t look right with the o-ring in it but will give it a go... still a few randoms spare but will just keep them spare. Coming from Keihin’s it deffo looks like the carb off of a scooter... lawnmower even. ?

Bike is a 2007 TXT Pro 250 - rebuilding the carb with new seal kit... a little confused as its got more seals/orings/spacers than there are bits in the carb... specificallly confused about: Carb top o-ring: bike has never had one, carb top has a lip on it and it seals against the cap... o-ring fits but when its tightened down it doesn’t look/feel right - was it missing or only on certain carbs/generations? Mixture screw: as above - none of the bushings fit, one small o-ring that looks like it should be on the needle... never had any to start with... missing or for other carb? Replaced the idle scre with new kit. Sussed out all the rest of it... never a dull moment working on these bikes... :-/ Kit came from splat shop... will also email them but any clues from your experience welcome. Carb well and truly needing the new seals, all perished.

Whatever is kicking about... usually Motorex Crosspower 2T @ 60:1 from my KTM 300 EXC.... runs fine. Had the head and barrel off recently, not issues apart from the rotten base gasket.

Fixed all the things that were very un-KTM like and have made me want to burn mine as I’ve been stripping it down: - No need to take the swingarm off just to replace the poxy slider (result - even if it is a good time to clean/grease everything) - No need to split the back braking circuit to get the swingarm off (happy days - bleeding from scratch is a PITA) - Can change crank seals from the outside (happy days - a wear item more likely to go than the bearings themselves on most two strokes) - Various other mods to make it easier to live with and work on Looks like a selection of useful mods to update the bike, playing at being Adam Raga on Eurosport can live on for me, who wants to be Toni Bou anyway?!? He rides a four stroke!

Cylinder back on and doing the dry fit up... got an S3 top end gasket kit a while back to do an exploratory inspection at some point.... the inner ring is the wrong size (too big) but the outside one is ok but not impressed with it... considering the two 10yr old rings back in. Better looking than the ones in the kit. Either that or another trip to the oilfield suppliers when I got to get a tyre for my trailer tomorrow... 250 inner gasket is 79mm x 1.78mm... got half a dozen 78 x 2mm viton ones from my 300 KTM there, outer ones are bigger though (105mm). Found the sizes on splat shop at least since they're not in the manual or on the S3 kit. https://www.splatshop.co.uk/gasgas-cylinder-head-o-ring-inner-250-280.html https://www.splatshop.co.uk/gasgas-cylinder-head-o-ring-outer.html Just saw that the water pump kit is £60+vat and £120 inc vat for a piston... no thanks. Not 100% certain the clutch side crank seal isn’t leaking... but its not smoking like there’s a new pope, will suck it and see.

Can’t hide the build quality on the Honda’s, even my old CBR600 still has that classy feel about it... but got a Honda four banger, like my other bikes smoking.

Got the barrel off there... late home but not cabbaged which always helps... Rate my piston here... https://imgur.com/gallery/frqRYdZ Looks ok, tight in the bore, maybe a little blow by? Bottom end is solid. Barrel in good condition, strong cross hatching, no lipping/scuffing Ring gap 0.4mm... what’s the limit on them? That’s the limit on my old old KTM 200 enduro... trials 250 more? looking like a new gasket and ride... ? That and an o-ring for the mixture screw on the 26mm Dellorto, it’s weeping.

Bugger... What about the Beta? Looks like a back to from GG....

A query from a relative newcomer who’s only owned a Gas Gas... are all trials bikes a PITA to work on, or is it just the Gassers? Assuming it could be all as they’re so tightly packaged but there’s a lot of things on that bike coming from years of owning Hondas and KTMs that I find downright odd and frustrating... sure they use them for trade testing Spanish bike apprentices.

Ouinon - thanks... water pump is easy to do anytime... in enduro land, piston is cheaper than a disaster... guess trials bike engine is more like a lawnmower? Piston looks sound, will get the barrel off and have a proper look though. richt - thanks for that, thanks a lot... only joking, thanks... a wee bit grimey in the magneto side last time, can check again... other side, it’s not smoking like its leaking... can suck it and see... Good time to inspect and measure at least....

Still needing feedback regarding the crank seals... engine out and cases split? Stripping the bike going well... stripped half the bike just to get at the barrel... only the barrel to remove now, its a little stuck... try again tomorrow when less tired. Had enough excitement for one day. Cylinder looks good inside, no lipping, strong cross hatching... bolts not very tight, assume that’s how the leak developed. Now... do we go for a water pump refurb and a new piston? After all that striping I think so...

I suffered from this.... GG UK also ship to me in Abu Dhabi... France should be ok too....

Do you need to split the cases to do the crank seals?

Interested to see if that fixes the neutral issue... I roll the revs up and snick it up from first gear with the clutch in, it also works.

Revised to account for developing scope.... Went out for a run this morning and noticed what looked like a leak, wasn’t sure if it was from the cylinder or the bike had boiled over. Checking it out when I got back in, looks very much like a leak... thought it was idling high. Backfire on one of the kickstarts a tell tale. Pics on this link: Gasket Leak & Plugs It’s run a little lean... think the gasket has been on its way the last few rides. Is this a common failure on these bikes? Or sign of something else failing? Google indicates it may be a common issue.... got a gasket kit there. Only recent changes have been a few rides on 60:1 premix (motorex same as used in the KTM 300... did add 10mm to the tank this morning though). Any suggestions on other works to be carried out whilst the barrel is off? What are the ring gap and squish settings for these bikes (which don’t have workshop manuals unlike the KTMs!)? Will get more pics when its stripped... got a pool pump to rebuild first.

Squeak Squeak

Yes..... dremmel and some 400 grit paper to finish..... I tried oil in the bottom end, oil in the plug hole, still made it, was taking the casings off to start digging in and saw it. It was corroded and it was the flywheel squeaking on the coil, had been getting in the pulser coil opening, bottom part of the casing gasket had a bit out of it.... googled it and it appeared to be a thing.