drca Posted October 21, 2018 Report Share Posted October 21, 2018 I have a 2013 TXT PRO 250 that I purchased used a couple of years ago with unknown number of hours. I probably put 400 hours on the bike since I bought it. I am wondering how many hours these bikes go before needing a top end rebuild. It's running fine, but it feels easier to kick than when I purchased the bike (which just might be me getting used to kicking it...) I haven't measured the compression yet, but I could do that if someone tells me what numbers I should expect from a compression test (and how to measure: carb on / off, reed box on/off, pipe on/off etc...). When doing a top end rebuild, what's needed (beside the gaskets)? Rings only? Piston? Thanks. DC Quote Link to comment Share on other sites More sharing options...
stpauls Posted October 21, 2018 Report Share Posted October 21, 2018 How long is a piece of string? Quote Link to comment Share on other sites More sharing options...
oni nou Posted October 21, 2018 Report Share Posted October 21, 2018 (edited) 5 hours ago, drca said: I have a 2013 TXT PRO 250 that I purchased used a couple of years ago with unknown number of hours. I probably put 400 hours on the bike since I bought it. I am wondering how many hours these bikes go before needing a top end rebuild. It's running fine ITS RUNNING FINE ............If it is running fine why does it need fixing.The owners manual says change once a year for the cylinder, cylinder head , piston and rings ....this seems a little excessive if for example you only used the bike twice in a year for approx. 8 hours.........I would go with just use it until the top end starts to make a noise and then have the cylinder nikasil plated and put a new piston and rings in .and con rod kit if it needed one of those aswell.https://youtu.be/rDgXeYlpbOE?t=2m58s Edited October 21, 2018 by oni nou 1 Quote Link to comment Share on other sites More sharing options...
sprinter 27 Posted October 21, 2018 Report Share Posted October 21, 2018 If you know of 400 hr with unknown before I’d be inclined to throw a piston and rings in it . As others have said it’s tough to give a set amount as air cleaner shape, type of running , water ingress all makes a difference. But 350 hours on an avg trials bike seems reasonable to freshen it . Waiting only will increase the possible wear issues on the nikosil coating or possible catastrophic outcome of broken top end components 1 Quote Link to comment Share on other sites More sharing options...
peterb Posted October 21, 2018 Report Share Posted October 21, 2018 A good friend of mine, who rides trials regularly all through the year, went 10 years on a GG 330 without taking the head and cylinder off, and it still did not rattle and still performed as good as the day he bought it. There would have been many more hours than 400 on that bike. If you haven't drowned your bike in water and the motor doesn't have a piston rattle and it is still going well, then I'd be inclined to leave it alone, the top end is rather hard wearing with a nikasil bore, as mentioned earlier and rings which I am pretty sure are nitrided. Bye, Peter B. 1 1 Quote Link to comment Share on other sites More sharing options...
misscrabstick Posted October 21, 2018 Report Share Posted October 21, 2018 If it runs fine with no untoward noises just keep riding it. Quote Link to comment Share on other sites More sharing options...
section swept Posted October 21, 2018 Report Share Posted October 21, 2018 B’dang..ding, ding, ding...B’dang..ding, ding, ding...well that sounds ok I’ll leave it until it goes pop!!! 2013 unknown hours of operation on a two stroke plus the additional 400 hours added by the current owner...that would be a good time to lift the barrel and have a look see what wear is taking place. It’s better than internet crystal ball gazing??At least you would finally know what the actual mechanical condition wear wise of the top end is in. If you equate hours to miles at say (for a Trials bike) using your known 400 hours multiplied by a nominal 15 miles per hour you arrive at 6,000 miles. So if the previous owner warmed the engine up before use and did all the planned maintenance when needed let’s guesstimate at least the same amount of time/hours so that’s another 6,000 miles totalling 12,000 miles. Yes I know that the bike did not cover 15 miles constantly, this would have been stop, start running interspersed with high revs and medium revs to very low revs running, but you need a reference data point. As it’s a 2013 model it’s at least 5 years old and if I owned said bike it would be having new crankshaft oil seals, and dependant upon what was found wear wise at least new rings. The barrel would be decoked together with the exhaust system. Due to the vagueness of actual hours of engine usage, remember my data reference has no idling and blipping the throttle time added, to an extent I too am crystal ball guessing so nothing is an exact science here, but I would be planning to strip the top end?? 1 Quote Link to comment Share on other sites More sharing options...
heffergm Posted October 21, 2018 Report Share Posted October 21, 2018 In my largely worthless opinion, 500 hours is about time to do a piston and rings. Quote Link to comment Share on other sites More sharing options...
oni nou Posted October 21, 2018 Report Share Posted October 21, 2018 (edited) Don't forget to strip down the whole bike while youre at it .......I mean everything with that many hours on the bike the forks will need new damping cartridges new bushings and seals all the wheel bearings will need changing and have the hubs checked with dye under ultra violet for stress cracks ...any spokes and nipples that have corroded and are fused will need changing and the rims need checking for trueness and de stressing......better get a new rear shock as well; you do not want that collapsing with catastrophic results......the frame will need checking for stress and cracks..... if that fails youre really in it ...probably best to get a new one to be on the safe side....change the sump guard as well as a deformed one may lead to stress in the frame that leads to cracks in the motor casings.....the dog bones will need renewing and linkage bearings all replacing ....swing arm needs testing for cracks before that ends in some hapless spectators being maimed.......that things an accident waiting to happen. the gearbox will need replacing as well that will have taking a bashing over the years. Edited October 21, 2018 by oni nou 2 Quote Link to comment Share on other sites More sharing options...
drca Posted October 22, 2018 Author Report Share Posted October 22, 2018 Thanks for all the answers (altho I didn't get the piece of string reference...). The 400 hours is based on riding 3 times a week for about 1.5 hours of bike running per session for about 30 weeks a year. Maintenance wise, here is what has been done: when I bought the bike I took it completely apart and even stripped the frame to the bare metal to inspect and have a few issues fixed: dings in the upper frame tube, rear engine mount cracked. I had the frame, swingarm and fork bottoms powder coated. I rebuilt the rear suspension (all bearings, bushings, seals and fork (seals, bushings, oil change) and the steering bearings. Rebuilt the front and rear brake calipers with new seals all around, new pads too. Then the usual new grips, folding lever, ban ends, chain and sprockets, new air filter, cleaned (ultrasonic) and rebuilt the carb, new reeds (carbon), new sparkplug, and new plastic and sticker kit all around (I recommend the Jitsie rear fender - indestructible!). Since that initial work, I have changed the bash plate and rubbers twice a year (yeah, sportsman rider here!). I check the wheels and rim every time I change the tires (see my other post on corroded rear rim). Wheel bearings are fine, but since they are cheap I'll probably change the this winter anyways. The rear engine mount cracked again (other one), so I had that fixed too. Engine wise I rebuilt the water pump, changed the radiator (bad fall!), fan (whinny fan syndrome due failed bearing) and the hoses (silicone ones). I had to change the clutch basket / main drive gear (see my other post on that, my mistake, the thrust bearing fell in the engine when I put the side case back). New kickstarter seal. I have a brand new exhaust (full set that I got from a guy who turned a brand new bike into an electric one) that I'll probably put on at one point, maybe this winter. Things to do this winter: full service (break it down to the frame, check and lube all the bearing and seals, replace the ones need replacement), new grips, fluid flush (coolant, brake, clutch), new fork (I bent the Marzocchi and I just bought a used Tech in like new condition), probably new rear shock (Ohlins). New wheel bearings, new bash plate and associated rubber pads. Switch from the Dell'Orto to a PWK (carb, intake manifold, reed box, cable). New clutch plates. Probably new clutch pedal (current one is wobbly and has been bent a couple of time). I'll probably throw in a new piston and rings too while the engine it out of the frame. Full bottom end rebuild will probably wait another year... Thanks again for the help. 1 Quote Link to comment Share on other sites More sharing options...
oni nou Posted October 22, 2018 Report Share Posted October 22, 2018 11 hours ago, drca said: Thanks for all the answers (altho I didn't get the piece of string reference...). The 400 hours is based on riding 3 times a week for about 1.5 hours of bike running per session for about 30 weeks a year. Maintenance wise, here is what has been done: when I bought the bike I took it completely apart and even stripped the frame to the bare metal to inspect and have a few issues fixed: dings in the upper frame tube, rear engine mount cracked. I had the frame, swingarm and fork bottoms powder coated. I rebuilt the rear suspension (all bearings, bushings, seals and fork (seals, bushings, oil change) and the steering bearings. Rebuilt the front and rear brake calipers with new seals all around, new pads too. Then the usual new grips, folding lever, ban ends, chain and sprockets, new air filter, cleaned (ultrasonic) and rebuilt the carb, new reeds (carbon), new sparkplug, and new plastic and sticker kit all around (I recommend the Jitsie rear fender - indestructible!). Since that initial work, I have changed the bash plate and rubbers twice a year (yeah, sportsman rider here!). I check the wheels and rim every time I change the tires (see my other post on corroded rear rim). Wheel bearings are fine, but since they are cheap I'll probably change the this winter anyways. The rear engine mount cracked again (other one), so I had that fixed too. Engine wise I rebuilt the water pump, changed the radiator (bad fall!), fan (whinny fan syndrome due failed bearing) and the hoses (silicone ones). I had to change the clutch basket / main drive gear (see my other post on that, my mistake, the thrust bearing fell in the engine when I put the side case back). New kickstarter seal. I have a brand new exhaust (full set that I got from a guy who turned a brand new bike into an electric one) that I'll probably put on at one point, maybe this winter. Things to do this winter: full service (break it down to the frame, check and lube all the bearing and seals, replace the ones need replacement), new grips, fluid flush (coolant, brake, clutch), new fork (I bent the Marzocchi and I just bought a used Tech in like new condition), probably new rear shock (Ohlins). New wheel bearings, new bash plate and associated rubber pads. Switch from the Dell'Orto to a PWK (carb, intake manifold, reed box, cable). New clutch plates. Probably new clutch pedal (current one is wobbly and has been bent a couple of time). I'll probably throw in a new piston and rings too while the engine it out of the frame. Full bottom end rebuild will probably wait another year... Thanks again for the help. Seems like you are the kind of rider that could justify buying a new bike and then change it every 6 months and put an end to all the work you keep doing on the bike. Quote Link to comment Share on other sites More sharing options...
faussy Posted October 22, 2018 Report Share Posted October 22, 2018 Youre my kinda guy! I find trials riders to be some of the laziest regarding maintenance, then again the sport maybe doesnt require as much as mx or circuit racing, but it doesnt hurt to be on top of things. I salute you Quote Link to comment Share on other sites More sharing options...
miner Posted November 10, 2018 Report Share Posted November 10, 2018 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. 1 Quote Link to comment Share on other sites More sharing options...
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