jeepwm69 7,611 Posted February 20 @basfnb bought this one a few years ago. Between his kid and the other neighborhood kids, it appears they've wrecked the transmission. It's stuck in gear and won't do anything. I took the sub-transmission off the side and didn't see anything there that looked out of place, so the next suspect will be a bent shift fork or similar. He's whined about how long I've had it, but I always tend to do stuff I know how to do before I dive off into an unfamiliar engine, but I finally pulled the engine in the fall and took it into the shop, and started tinkering on it the other day. First thing I found out was that it has JIS screws instead of usual 8mm or 10mm bolts, and my JIS bits don't fit my driver, so I had to order a set of JIS screwdriver bits to get this thing apart. I'll post pics moving forward, as much for myself as anything. I have two of these that are basket-case TRX125's, same year, with the hope of having one running one for the little one when she's ready. 2 Share this post Link to post Share on other sites
shadetree 5,869 Posted February 21 if you need any parts for it ?, holler at me, i bet i know where some are ?!..lol. 1 1 Share this post Link to post Share on other sites
jeepwm69 7,611 Posted February 21 Well this one is @basfnb's. I have two more just like it that I'm going to hopefully be able to build into one good one for the little princess. I'll practice on his crap just in case I mess it up! Had to order a flywheel puller this morning, and need to get a gasket kit ordered. These sideways engines are weird! 1 Share this post Link to post Share on other sites
jeepwm69 7,611 Posted February 22 Got very little done this morning. Discovered the clutch nut is a weirdo and had to order a special tool for it. Dang JIS screws everywhere on this engine instead of regular hex head bolts! I also have discovered that there are no rings in stock anywhere for this machine. Plan was to hone the cylinder and put new rings on it while I had it apart. Share this post Link to post Share on other sites
jeepwm69 7,611 Posted February 28 Got clutch puller yesterday, so back to work. Symptoms of this one was locked up shifter. Wouldn’t shift up or down. I expected sub transmission problems but didn’t find anything out of the ordinary there, and it still wouldn’t shift with the sub transmission removed. So this morning I got the clutch off and started looking at the shifting mechanism and it appears to shift now…..plan was to split cases and I think I still will given that I’m this far in, but is it possible the shift mechanism was just jammed up? Don’t know if anyone other than @shadetree here has any experience with these. I did notice that when in is what I presume is neutral, this shaft will spin a bit in either direction, but then stops. Wondering if that might be my problem. IMG_3009.MOV Share this post Link to post Share on other sites
jeepwm69 7,611 Posted February 28 Shaft i was referring to. Will turn several full turns but then locks up. Does the same in either direction. IMG_3010.MOV Share this post Link to post Share on other sites
walhonding300 53 Posted February 28 I cannot help you with any of the mechanicals because I wouldn't have a clue lol. Just wanted to comment that I bought one of these for my son as his first 4 wheeler when he was 8. Paid $1000 for it. Ran good. $55 for a battery and a case of beer to my atv guy and made it run perfect. Sold it last year for $1000. I think anyone that spends $3000 for a brand new youth ATV is wasting their money. Find one of these good old machines for a kid. I thought it was safer anyway. Heavier. Didn't take off fast. Kept it value. 1 Share this post Link to post Share on other sites
jeepwm69 7,611 Posted February 28 I have two more of them just like it behind my shop. Paid $100 for one, $50 for the other. They are both beaters that I expect will need a rebuild, but hopefully i can piece two of them together into one working machine for my little girl when she's ready. After messing with a couple of Tao Taos I told my friends name brand stuff only, and to buy older stuff, let their kids ride them, and then sell them for the original purchase price a few years later. Can't beat free usage of kids' toys! Share this post Link to post Share on other sites
jeepwm69 7,611 Posted March 2 Well I got 6 of the 9 JIS crankcase screws out. Stripped the other 3, so will have to drill the heads off.🤬 Share this post Link to post Share on other sites
jeepwm69 7,611 Posted March 5 Found my old hand impact driver and lo and behold the JIS bits I bought a while back that wouldn't fit in my Milwaukee impact DO fit in the hand impact driver, so I was able to get the remaining 3 JIS bolts out without having to cut/ drill them. I didn't find anything that looked bad at all with the transmission, so spent over an hour scraping gaskets and cleaning the crankcase halves, and will try to get the center cases back together with a new gasket in the morning if I can drag myself out of bed. Still haven't figure out why the thing wouldn't shift. I haven't found anything bent or broken. It's almost like something was bound up a bit and freed up when I took everything apart. Share this post Link to post Share on other sites
jeepwm69 7,611 Posted March 7 Been plugging away on the gaskets on this thing. Nothing like rock hard 40 year old gaskets to make you want to toss the whole project in the lake. These early Honda engines have gaskets on EVERYTHING too. No Hondabond anywhere, all paper gaskets. I probably have 4-5 hours just in gasket scraping on this engine. You can see the pile of gasket bits from this morning up next to the ratchet. The rings I had to order from Australia should be here today. Apparently pistons and rings for these 125's have become impossible to find. I've noticed piston supply for even common engines hasn't really come back post-covid. Seems the 125's are pretty much unobtanium now, which stinks because I have two of them out back and am worried I won't be able to get rings for them when the time comes. So, while we're on the subject, any "tricks of the trade" for these ancient, rock hard gaskets? 1 Share this post Link to post Share on other sites
retro 4,048 Posted March 8 11 hours ago, jeepwm69 said: So, while we're on the subject, any "tricks of the trade" for these ancient, rock hard gaskets? A boiling water bath helps a bit but usually not quite enough... a razor blade scraper is usually what I end up with in my hand. 2 Share this post Link to post Share on other sites
jeepwm69 7,611 Posted March 14 Found the shifting problem. Spinning the transmission on the bench was catching in either direction. Transmission gear on the input side of the transmission. 1 Share this post Link to post Share on other sites
shadetree 5,869 Posted March 14 On 3/7/2024 at 9:20 AM, jeepwm69 said: Been plugging away on the gaskets on this thing. Nothing like rock hard 40 year old gaskets to make you want to toss the whole project in the lake. These early Honda engines have gaskets on EVERYTHING too. No Hondabond anywhere, all paper gaskets. I probably have 4-5 hours just in gasket scraping on this engine. You can see the pile of gasket bits from this morning up next to the ratchet. The rings I had to order from Australia should be here today. Apparently pistons and rings for these 125's have become impossible to find. I've noticed piston supply for even common engines hasn't really come back post-covid. Seems the 125's are pretty much unobtanium now, which stinks because I have two of them out back and am worried I won't be able to get rings for them when the time comes. So, while we're on the subject, any "tricks of the trade" for these ancient, rock hard gaskets? not sure how many times i've told you ?, but a bench grinder with a wire wheel is what i use along with a razor blade, my trusty old pocket knife is how i get the old gasket off the parts. Share this post Link to post Share on other sites
shadetree 5,869 Posted March 14 5 hours ago, jeepwm69 said: Found the shifting problem. Spinning the transmission on the bench was catching in either direction. Transmission gear on the input side of the transmission. you got that shaft ?, i bet i know where you can find one !..lol. as for the rings ?, a simple ebay search will locate aftermarket rings, been there..done that. you can get the whole cylinder, topend gaskets, rings, piston ( aftermarket ) to fit this atv. yes..i know its china aftermarket ?!. but when it comes to old parts that are no longer around ?, you have no choice but to bite the bullet, and do what ya gotta do to make it work. Share this post Link to post Share on other sites
jeepwm69 7,611 Posted March 14 31 minutes ago, shadetree said: you got that shaft ?, i bet i know where you can find one !..lol. as for the rings ?, a simple ebay search will locate aftermarket rings, been there..done that. you can get the whole cylinder, topend gaskets, rings, piston ( aftermarket ) to fit this atv. yes..i know its china aftermarket ?!. but when it comes to old parts that are no longer around ?, you have no choice but to bite the bullet, and do what ya gotta do to make it work. Well this is @basfnb's, so I ordered one off of ebay. I have two of these in the yard, but didn't want to tear down an engine for a $30 part (got the whole input shaft with all the gears). And the afternarket cylinders, pistons, rings, etc have all dried up for these! Hopefully it's temporary, but it's all unavailable now! Nuts! Gaskets are no problem, but the others bits are unobtainium. Share this post Link to post Share on other sites
shadetree 5,869 Posted March 15 6 hours ago, jeepwm69 said: Well this is @basfnb's, so I ordered one off of ebay. I have two of these in the yard, but didn't want to tear down an engine for a $30 part (got the whole input shaft with all the gears). And the afternarket cylinders, pistons, rings, etc have all dried up for these! Hopefully it's temporary, but it's all unavailable now! Nuts! Gaskets are no problem, but the others bits are unobtainium. yeah, just did a quick search on ebay, no std rings, couple over size though. even checked my honey hole web site, they had 3rd size over rings. Share this post Link to post Share on other sites
