blakep82 Posted February 2, 2019 Report Share Posted February 2, 2019 Hi, seems to the the done thing to write some sort of intro, so, I bought my first trials bike a few weeks ago, a GasGas txt 321 (1999) needs a few things doing to it, but i've never had a bike before, so unfortunately for you lot, lots of probably really stupid questions will be coming! first one would be, I've got to fit a rubber tensioner block, can it be done without splitting the chain (no chain splitting tool, no idea what chain it is, how to measure its pitch, or know what new master links to buy) wish me luck lol Blake Quote Link to comment Share on other sites More sharing options...
Bilko Posted February 3, 2019 Report Share Posted February 3, 2019 Looking at the pic looks like you need a new chain with the slack even without the tensioner,but as for fitting without splitting chain are you sure there is not a split link.there are 2 types of pads 1 open and 1 where you would have too split the chain and feed through it.As for chain size should be 520.pitch Quote Link to comment Share on other sites More sharing options...
peterb Posted February 3, 2019 Report Share Posted February 3, 2019 Looks like a LWB Series III Land Rover holding the bike up. Good bikes those 321's, grunty motor, not much goes wrong. You don't need to buy a new master link, just undo the spring link and re-fit with pliers, closed end of the spring facing direction of chain travel going forwards. Keep the air filter clean, clean out the air filter box, they don't seal very well so water does get in, strip the carb and blow out all the passage ways and re-assemble. Needle is a D36, clip position 2nd from bottom, pilot screw set from 3 1/2 turns out from fully in, as a starting point. Out to richen, in to lean. You don't need a Gas Gas specific chain pad, most blocks will fit from other trial bikes, check the bolt hole distance between centres. Change the gearbox/clutch oil, it says 700mL on the casing but 650mL is fine, I always have used ATF rated to Dexron III as my preferred oil for well over 20 years, it's cheap and it works well, others have their own opinions. Great bike in it's day, not so easy to find wheel grip in the mud, a good Scottish bike. Bye, Peter B. Quote Link to comment Share on other sites More sharing options...
blakep82 Posted February 3, 2019 Author Report Share Posted February 3, 2019 (edited) 8 hours ago, Bilko said: Looking at the pic looks like you need a new chain with the slack even without the tensioner,but as for fitting without splitting chain are you sure there is not a split link.there are 2 types of pads 1 open and 1 where you would have too split the chain and feed through it.As for chain size should be 520.pitch Thanks Bilko, you may well be right, never had a bike before so i dont really know what the tolerances are. At the momeng, im far from a pto, and still witking on my balance so this chain will do for now, but ill be looking soon to get a new chain and sprockets. Any recommendations on manufacturers? I had a look for a split link last night, couldn't see one, but couldn't really get round the bike properly to see. Very full garage. I'll try again today Thanks! Edited February 3, 2019 by blakep82 Quote Link to comment Share on other sites More sharing options...
blakep82 Posted February 3, 2019 Author Report Share Posted February 3, 2019 7 hours ago, peterb said: Looks like a LWB Series III Land Rover holding the bike up. Good bikes those 321's, grunty motor, not much goes wrong. You don't need to buy a new master link, just undo the spring link and re-fit with pliers, closed end of the spring facing direction of chain travel going forwards. Keep the air filter clean, clean out the air filter box, they don't seal very well so water does get in, strip the carb and blow out all the passage ways and re-assemble. Needle is a D36, clip position 2nd from bottom, pilot screw set from 3 1/2 turns out from fully in, as a starting point. Out to richen, in to lean. You don't need a Gas Gas specific chain pad, most blocks will fit from other trial bikes, check the bolt hole distance between centres. Change the gearbox/clutch oil, it says 700mL on the casing but 650mL is fine, I always have used ATF rated to Dexron III as my preferred oil for well over 20 years, it's cheap and it works well, others have their own opinions. Great bike in it's day, not so easy to find wheel grip in the mud, a good Scottish bike. Bye, Peter B. Indeed it is! 1973 series 3, love it I looked for a spring link last night, couldn't see one, but could only really see one side of the chain, where it's sitting. I've got another car in he garage and old stock car, so not much space! Some good tips there, thank you! I've got it starting and running fine, but the cleaning out of the carb is definitely on the list, as is a decent service, so some good tips there, thank you Quote Link to comment Share on other sites More sharing options...
blakep82 Posted February 3, 2019 Author Report Share Posted February 3, 2019 I ended up doing a temporary job for now by cutting down the side of the block to slip it over the chain, then immediately found the split link. Oh well! 1 Quote Link to comment Share on other sites More sharing options...
konrad Posted February 3, 2019 Report Share Posted February 3, 2019 (edited) The TXT 321 was my first trials bike. I spent considerable time getting the clutch to work to my liking (zero drag). Since this is your first motorcycle, you may not be too critical of that fault, but having the bike work properly will help prevent you from developing bad habits. A good trials habit is to have one finger (and only one finger) always on the clutch lever. Anyway, I made sure everything was perfect with my clutch components and it still would not disengage completely with the lever pulled to the bar. Eventually, with the clutch cover removed, I noticed that it was easy for me to rotate the pressure plate by hand when the clutch was disengaged. There was little drag and no tendency for it to rotate the engine. This gave me an idea. I rode the bike briefly with no oil in the gearbox. Guess what -- the clutch disengaged completely! I then refilled the gearbox 300cc short of the "correct" fill. This also produced nearly zero clutch drag. Although neither an owner's nor service manual seems to exist for this bike, internet sources say the correct gearbox fill is 650 - 750cc. There is a sight glass on the clutch housing that I had been using. I would guess it takes about 800cc to get the level in the middle of the sight glass. So when I fill 300cc short, I probably have about 1/2 liter in the gearbox. There is an advantage to having a lot of oil in the gearbox in that (short term) it can act as a heat sink and allow the clutch to work longer before overheating and slipping. As a new rider you probably will not be abusing the clutch to that extent anyway. Regarding Peterb's recommendation of using ATF, I agree completely. I tried every transmission fluid known to man in that 321 and nothing was any better than ATF, which is cheap and readily available. I use it on most 2T gearboxes now. I'll end with a story from Kevin Cameron about Kawasaki's KR250 road racer (circa 1975). The KR250 had a very tight gearcase, and when given its "correct" fill of 1,100cc of gear oil, it got so hot it burned the black paint right off the casting. Cutting the fill to 600cc made the situation tolerable, if not desirable. Edited February 3, 2019 by konrad Quote Link to comment Share on other sites More sharing options...
blakep82 Posted February 4, 2019 Author Report Share Posted February 4, 2019 22 hours ago, konrad said: The TXT 321 was my first trials bike. I spent considerable time getting the clutch to work to my liking (zero drag). Since this is your first motorcycle, you may not be too critical of that fault, but having the bike work properly will help prevent you from developing bad habits. A good trials habit is to have one finger (and only one finger) always on the clutch lever. Anyway, I made sure everything was perfect with my clutch components and it still would not disengage completely with the lever pulled to the bar. Eventually, with the clutch cover removed, I noticed that it was easy for me to rotate the pressure plate by hand when the clutch was disengaged. There was little drag and no tendency for it to rotate the engine. This gave me an idea. I rode the bike briefly with no oil in the gearbox. Guess what -- the clutch disengaged completely! I then refilled the gearbox 300cc short of the "correct" fill. This also produced nearly zero clutch drag. Although neither an owner's nor service manual seems to exist for this bike, internet sources say the correct gearbox fill is 650 - 750cc. There is a sight glass on the clutch housing that I had been using. I would guess it takes about 800cc to get the level in the middle of the sight glass. So when I fill 300cc short, I probably have about 1/2 liter in the gearbox. There is an advantage to having a lot of oil in the gearbox in that (short term) it can act as a heat sink and allow the clutch to work longer before overheating and slipping. As a new rider you probably will not be abusing the clutch to that extent anyway. Regarding Peterb's recommendation of using ATF, I agree completely. I tried every transmission fluid known to man in that 321 and nothing was any better than ATF, which is cheap and readily available. I use it on most 2T gearboxes now. I'll end with a story from Kevin Cameron about Kawasaki's KR250 road racer (circa 1975). The KR250 had a very tight gearcase, and when given its "correct" fill of 1,100cc of gear oil, it got so hot it burned the black paint right off the casting. Cutting the fill to 600cc made the situation tolerable, if not desirable. Yes, you're absolutely right about the clutch not fully releasing! Mine is exactly the same. I've not really tried sorting it yet, but it's in the just. It's impossible to get neutral when stopped, which is annoying. Have to kill the engine for neutral everytime. Interesting that too much (or rather the correct level ) of oil can do that. Obviously don't want to damage the gear box by not having enough in there. Some interesting ideas there, thank you! Quote Link to comment Share on other sites More sharing options...
Shauno Posted February 11, 2021 Report Share Posted February 11, 2021 On 2/3/2019 at 2:51 AM, peterb said: Looks like a LWB Series III Land Rover holding the bike up. Good bikes those 321's, grunty motor, not much goes wrong. You don't need to buy a new master link, just undo the spring link and re-fit with pliers, closed end of the spring facing direction of chain travel going forwards. Keep the air filter clean, clean out the air filter box, they don't seal very well so water does get in, strip the carb and blow out all the passage ways and re-assemble. Needle is a D36, clip position 2nd from bottom, pilot screw set from 3 1/2 turns out from fully in, as a starting point. Out to richen, in to lean. You don't need a Gas Gas specific chain pad, most blocks will fit from other trial bikes, check the bolt hole distance between centres. Change the gearbox/clutch oil, it says 700mL on the casing but 650mL is fine, I always have used ATF rated to Dexron III as my preferred oil for well over 20 years, it's cheap and it works well, others have their own opinions. Great bike in it's day, not so easy to find wheel grip in the mud, a good Scottish bike. Bye, Peter B. Hi what type of 2 stroke oil do you use and what ratio? Quote Link to comment Share on other sites More sharing options...
peterb Posted February 12, 2021 Report Share Posted February 12, 2021 I don't own an older GG any longer, and use Motul 800 2T fully synthetic oil in my modern bike. On the 321 I used a mineral based oil for the pre mix, at 50:1, but I think you would be fine with either Motul or Putoline synthetic 2T at 70:1 Bye, Peter B Quote Link to comment Share on other sites More sharing options...
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