Can I bring this scrap Yamaha XT500 dirt bike back to life? Pt1

追加: 2026-05-11

[00:00:13]Heat.

[00:00:17]Heat.

[00:00:23]Cool.

[00:00:49]So, I'm going to take a quick walk around this bike. um purely because the condition is just staggeringly bad.

[00:00:57]So from the the front wheel is loose and flat.

[00:01:03]Uh from what I can see, there's no wiring harness.

[00:01:07]Everything is fingertight.

[00:01:15]It's missing missing the flywheel. It was missing the cover.

[00:01:20]Uh carburetor was off. I've already rebuilt that. Uh the condition was actually Yeah. was terrible.

[00:01:27]Uh everything is loose.

[00:01:31]Um it looks like this this was stripped and quickly put together. Um the head is loose. It's missing the piston.

[00:01:42]Uh well, it's not missing the piston. I got a box of parts. The piston was in it. The owner said that uh the spike had low compression, so he was monkeying around in there. But we'll I'm going to be pulling the engine out now and we'll go through it and see what it needs.

[00:01:58]I've already bought I've bought a a gasket kit for it. Uh we'll check the inside of the cylinder, see what that looks like, see what the cams look like.

[00:02:09]Um just yeah maybe I might reassemble it, do a compression test just to see what if he was telling the truth or not.

[00:02:19]So pretty much I saw this bike on marketplace and this is such the Thumper is such an iconic bike.

[00:02:25]It's it just made me sad to see it in the condition that it was in. So picked it up.

[00:02:31]Um yeah, let's just see if we can get it at least started.

[00:02:36]I'm struggling to find parts for it, which I anticipated.

[00:02:40]Uh wiring harness I'm probably going to have to fabricate. Well, I just make one up. Um just to just to get see well see if we can get it running.

[00:02:49]The front forks are trash. Uh they're leaking all over the place. This is um been converted to a monoshock. Um that shock also probably needs seals. That's toast.

[00:03:04]Um, it's got no chain.

[00:03:07]It's got no foot pegs, uh, which I'm just cannot find anywhere.

[00:03:12]They just don't seem to exist. It's missing the oil return line, um, from the bottom end up to the the the oil tank and the frame.

[00:03:24]Uh, I wanted a project. This one, yeah, this one might be a bit more than I can handle, but we'll see.

[00:03:35]Yeah, let's get get it stripped down and get the engine out and have a look at it though. So, before I pull the engine out, um the bike did come with a few parts, uh used gaskets. Well, I don't know if these are used, but some of them are like came with a few gaskets.

[00:03:55]Uh, I think this is the bottom end.

[00:04:00]I think blowby filter or something along those lines. I think I'll have to double check.

[00:04:09]Uh, came with the points cover.

[00:04:15]This flywheel cover didn't come with I managed to find this on marketplace. Uh, it was missing. All right.

[00:04:22]Came with an axle.

[00:04:25]These are the those are the brackets for the seat.

[00:04:30]It came with a very dodgy looking coil.

[00:04:35]A couple indicators.

[00:04:38]Looks like an some kind of engine bracket.

[00:04:43]Back brake.

[00:04:47]Uh, more importantly, there's the piston and the the seller had also taken the points points out.

[00:04:55]So, I'm not super I'm not I'm not going to trust those. Um, I've bought some stuff for spec for this bike for the rebuild.

[00:05:05]Um, I got a new new gasket set and new coil, condensers, points, uh, new spark plug. I think it'll be a while till we need that.

[00:05:19]Um, I bought some pretty hand pretty levers, universal kill switch cuz I'm going to have to end up making my own wiring harness to try to get it running. uh some fuel hose, a new pepcock for the tank. It was missing. It's also missing the It's also missing the cap.

[00:05:41]And I bought a little flywheel puller.

[00:05:46]So, it did come with a whole bunch of nuts and bolts, which I've just stuck in some oil. And the I don't know if you can see in there, but the cam chain is also there. It's attached to that little zip tie.

[00:05:59]Um, I also bought uh clutch cables and a brake cable. Uh, cuz the ones the ones on the bike at the moment look quite rough.

[00:06:14]Um, luckily it had the decompression cable on it cuz I couldn't find one of those.

[00:06:21]Uh, but yeah, the engine. Sure. Yeah, the engine's a bit rough. See the points are missing.

[00:06:27]Um, I haven't tried to drain any oil or anything like that.

[00:06:35]This is loose.

[00:06:38]Yeah, everything's loose. Everything was just put sort of fingertight back on by the cellar.

[00:06:44]So, like the bolts are sticking out.

[00:06:46]Well, that's I don't I don't know why you bother that's not doing anything really, but at least it'll it should make taking it taking the engine out easier.

[00:07:00]Yeah. Yeah. Let's get the engine out and have a look at it and see what we can do.

[00:07:06]Okay, engine's out.

[00:07:13]Let's start getting it stripped down and see what we're working with.

[00:07:18]Okay. Um, everything seems to be fingertight.

[00:07:23]So, I think this the top head was stripped and the seller just quickly put it back together.

[00:07:50]Got some old silicone or something going on in here.

[00:08:04]It's just dirty.

[00:08:07]Doesn't Nothing seems broken.

[00:08:12]Let's have a look.

[00:08:19]or the cam bearings sound very crunchy.

[00:08:28]They don't look they don't look worn or anything.

[00:08:44]I have ordered new bearings for it and uh valve stem seals.

[00:08:51]Um another a full four full bolts kit.

[00:08:56]Okay, so the valve springs the valve springs seem okay. Um just a little bit dirty, a little bit of rust.

[00:09:11]Everything looks okay. It's just very dirty.

[00:09:25]Oh, valves are very carboned up.

[00:09:31]Maybe the valves weren't sealing nicely.

[00:09:33]could explain the I don't know, maybe the low compression the seller was talking about.

[00:09:39]I'll pull them out and have a look at them, clean them up, see how they seat in. Uh maybe we can just get away with lapping them, putting them back in.

[00:09:56]We have a mystery cloth.

[00:10:03]I don't know the set of uh the conrods in there. Um the probably put it in so that the conrod wouldn't hit the cylinder.

[00:10:18]Uh cylinder doesn't look too bad.

[00:10:22]I'll get you guys in here now.

[00:10:27]Yeah, some crosshatch.

[00:10:32]Doesn't look like there's any damage.

[00:10:35]Let's get the cylinder. Get the cylinder off and I'll show it to you guys.

[00:10:42]Yeah, this is definitely a part, which makes sense. The with everything being out, it's just coming apart too easily.

[00:10:51]So, let's try to get some lights in the thunder.

[00:10:55]Um, yeah, doesn't look too bad.

[00:11:04]Hopefully, we can get away just honing it and popping popping the piston back in.

[00:11:15]So, I'll grab the piston just to show it to you. So, this is the piston that came with the bike.

[00:11:25]The rings rings are aren't stuck.

[00:11:32]Um, it's a little bit of it's a little bit dirty that patch there. Maybe some blower.

[00:11:46]So, I don't know if you can see that, but it says 100 on it. So, this is a four oversized piston. Um, they go up in quarter mil increments.

[00:11:57]That means it's 1 mil oversized.

[00:12:01]Um, the interesting story about that is I'm struggling to find uh piston rings for it. I went into Yamaha.

[00:12:11]Uh, the one oversize or sorry, four times oversiz has been discontinued. Um, there are aftermarket replacements.

[00:12:19]Uh there's a WCO that comes with a full kit with the piston.

[00:12:24]Uh and Keo in Germany has just the rings as well. So I'll see how much the full a full set is.

[00:12:32]Uh it seems a bit of a waste. I don't know if the piston seems okay. There's no bits missing.

[00:12:38]Looks okay.

[00:12:40]It's got the wrist pin on it with the clip in there. The clip's not doing much. It's not holding it in. But I've I've got replacements anyway.

[00:12:51]Uh let's see.

[00:12:57]Everything's spinning nicely.

[00:13:01]Uh let's hold it up.

[00:13:13]Just trying to see if what the crank bearing is like. There's no up and down play on it at all.

[00:13:26]I did a little bit of little bit of side to side. No up and down, which is awesome.

[00:13:32]Uh there's quite a bit of rust.

[00:13:36]Let me get get you guys in here.

[00:13:43]So, there's quite a bit of rust on the inside, but it just looks like surface.

[00:14:00]No up and down play, which is fantastic.

[00:14:13]So, like you can see, the flywheel is off.

[00:14:19]Uh, it's not missing. I do have it. It's in quite rough shape. So, I'm going to try to get it cleaned up a little bit cuz I'm going to need it for for timing uh later on.

[00:14:28]Uh, this is the STA that came with the bike.

[00:14:32]Uh that's I'm going to take this off and send it to Wanda uh just to have a look at and make sure everything is working properly. Clean up the magnets.

[00:14:44]And so I'm not going to be needing I think this is the coil for general sort of electrics on the bike like lights and things like that. And I need to check the manual, but I think this is for ignition. So, I'm only going to be really using this because I'm not fixing this bike up and getting it roadw worthy. Uh, this is going to be a dirt bike. So, now let's get this off.

[00:15:36]I had done an ohm test on this and it didn't uh seem to be within spec, but I'm going to send it off to someone that knows what they're talking about just to be sure. I don't want to go through all an entire engine rebuild and then trying to figure out why it's not starting just because the status isn't working correctly.

[00:15:59]So, that's not too far. I'll just go drop it off, get them to have a a look over it to make sure everything's okay.

[00:16:06]The wiring is quite old. I'll maybe get them to replace that. I don't know.

[00:16:10]We'll see what they say.

[00:16:24]Um, I had to order another key as well for the flywheel. Uh, this it didn't come with didn't come with one. And I've gone through the little box of parts and bits and bobs that the seller gave me for the bike and I couldn't see anything in there.

[00:16:40]So, when I I've ordered quite a few bits and pieces off Keto. Uh, that was one of one of the things I ordered ordered from them.

[00:16:50]I'm just going to flip it around.

[00:16:54]That's heavy.

[00:16:59]Uh, I'll leave that casket on.

[00:17:05]So, let's take this off.

[00:17:24]And have a quick look at the oil filter.

[00:17:38]This engine was dry. It didn't have any There was no oil in it. Uh there was also no oil in the in the frame. So, I'm not expecting to make a big mess.

[00:18:18]Don't see any sparkles in it. So, doesn't look like there's any metal that I can see.

[00:18:27]Close moment.

[00:19:04]Heat. Heat.

[00:19:13]Heat up That's a clutch cover.

[00:19:56]Doesn't look too bad.

[00:20:21]So, it's a good thing I opened this cuz the seller was obviously messing around in here as well. This is all loose.

[00:20:36]So, okay.

[00:20:46]Doesn't smell burnt or anything. And I'm not going to play around with the clutch now.

[00:20:52]If I get it started, I'll whip that off and check everything.

[00:20:59]Cool.

[00:21:18]I think I'm going to leave it there for now until I get all my spares in and then we can start putting this thing together. see if we can get it get it started.

[00:21:31]Cool. So, it's been a few days since I've been able to work on this. I'm going to pull out the valves, uh, check them, and start cleaning everything up. Uh, if I have time, I'm going to try clean up the STA as well, which is a bit grubby.

[00:21:47]Yeah.

[00:21:51]Heat up here.

[00:22:44]So, the inside valve was a real pain to get out. Um, I thought it might actually be bent, but it seems quite straight. It's just stuck.

[00:22:58]Yeah, there's no wobbles there. I'll check the exhaust valve.

[00:23:23]Yeah, they both look good. It was must have just been stuck.

[00:23:32]Uh, so I'm going to try clean up the valves. Uh, this is just a bit of uh skyropad or Scotchbrite.

[00:23:40]Um, yeah, let's try clean them up a little bit. There's quite a lot of carbon on here.

[00:23:48]See if we can try to shine it up underneath of this one. This seems quite rough and I think the battery on my drill is dying. Yeah, I'm going to do the other valve and throw them in the ultrasonic cleaner and carry on from there.

[00:24:14]>> Valves are out of the ultrasonic cleaner. Uh they're much better, but they're not I wouldn't call them great.

[00:24:22]So, the rocker box and the cylinder head are out of the ultrasonic cleaner. I cleaned them clean them up after that.

[00:24:29]uh scrubbed them up with some carb cleaner and I took a a plastic bristle brush uh to the mating surfaces and they cleaned up. They seem to have cleaned up quite well.

[00:24:43]Very happy. So, uh looking at the valves closer, the the intake valve I really struggled to get out. Um I thought it was either bent or there was dirt in the in the inside. Uh, I've cleaned everything up, checked the valves.

[00:25:02]The the valves aren't the valve isn't bent, but if you look closely at the tip, it's tapered out like that.

[00:25:16]So, the tip of the valve diameter is outside the it shaft.

[00:25:23]So, I think this motor is beginning to make a lot more sense to me now and why it was essentially put in a parts bike.

[00:25:31]Um, I think the the valve clearance was too high or there wasn't enough oil and with the rocker hitting it has just bent it out of out of shape. So I was trying to Why it was so difficult is this was wider than the channel it was coming out of.

[00:25:53]Um I think I dodged the bullet there. So and the exhaust the bottom of that valves looks like the surface of the moon. It's so it's so pitted.

[00:26:09]So I went and picked up uh two new valves cuz I'm not putting these in. Uh yeah, definitely not. These are going in the rubbish bin.

[00:26:18]So, I'm going to lap these valves in now.

[00:26:24]So, this is the the coarse compound and then the fine compounds underneath.

[00:26:56]Heat. Heat.

[00:27:04]Heat.

[00:27:21]Heat.

[00:27:48]Okay. So, I've put new valve seals in there and there.

[00:27:54]And I'm going to put the valves in. Put the springs back on and then this head should be done.

[00:28:45]Okay, then you've all I was struggling to do it and keep a good camera angle. Uh, so I just killed the camera and finished him off.

[00:29:01]Yeah. So, that's the head head done, all cleaned up, ready to go. I dropped my cam shaft off with the mechanic today to get the bearings put on. So hopefully I'll get that back soon and we can start getting the this engine back together.

[00:29:20]So I went ahead and changed the rocker arms and the the camera wasn't recording when I did it. So I'm just going to do a walk through of what I did. This was the original rocker arm that was in the bike.

[00:29:35]And right there, there's actually a very deep groove worn into the rocker. So, luckily, I was managed I managed to get a decent set of secondhand ones from the same guy that I bought the valves and I've swapped them out. So, yeah, that would have caused all kinds of problems. And it it actually makes sense why the cuz this was the rocker cover for the intake valve.

[00:30:03]Uh the the damage to this the top end on this is also is starting to make a lot more sense now. So this was worn out.

[00:30:10]Maybe the the valve clearance I don't know wasn't set properly or lack of oil.

[00:30:16]But this is this is very very bad.

[00:30:21]So these are the new these are the new well the secondhand ones but in better shape rockers that I put in.

[00:30:30]uh to to swap them out, you take these two bolts out and the axle or the spindle that goes through the rockers is inside behind these behind these two bolts. So to get them out, um I had to look it up in the manual. You take one of it's a six more bolt out of the clutch cover and this the the little spindle that holds the rockers in place is threaded and you thread this insert and then I used they were actually I couldn't just pull them out with my fingers. I ended up having to use a slide hammer. Uh but on the first hs it came out so they were a little bit stuck so I took them took them out, cleaned them up, oiled them up, put the new rockers in, put the bolts back on.

[00:31:18]So today, while I'm killing time, waiting for the rest of my spares to arrive that I ordered, I'm going to put the flywheel and sta back on.

[00:31:27]I got a new uh wood drift key, which was missing, and a new nut for the flywheel.

[00:31:41]Heat.

[00:31:53]Heat.

[00:32:02]Heat.

[00:32:16]Heat.

[00:32:35]Heat.

[00:32:37]Heat.

[00:32:56]Okay, so the flywheel's back on. I'm just going to take this cover off the bottom uh to check the There's a There's an filter inside here. I want to have a look at it and clean it up.

[00:33:27]Dad.

[00:33:28]>> Oh, wow.

[00:33:32]>> Um, mom said she really, really wants a cup of tea because she wants a cupcake.

[00:33:38]>> Okay, tell her I'll come make a tea now.

[00:33:40]>> Okay.

[00:33:43]Okay, so that's the square key for the timing gears that I had to order cuz I thought it was lost. It was obviously when they were taking it off, it fell in the bottom.

[00:33:54]If you can see that there's another type of pin, another pin in there.

[00:34:10]Going have to try to figure out where that came from.

[00:34:20]Cool. So, I've got the bottom cover cleaned up. Um, all the surfaces are nice and clean. There was a lot of sludge in there that I sorted out.

[00:34:27]Cleaned up the mating surf uh surfaces and the this little screen.

[00:34:33]Going to pop a new gasket on. Throw it back on.

[00:35:07]So, I'm going to pop the oil line back on. Um, I thought before I did it just looked a little bit grubby. I just hit it with a wire wheel and gave it a coat of black.

[00:35:50]Heat. Heat.

[00:36:16]Heat. Heat.

[00:36:45]Tommy marks at 12:00.

[00:36:49]These two top marks are correct.

[00:36:55]The issue I'm having is top dead center on the flywheel.

[00:37:02]Should be there.

[00:37:04]So, I think when I put the flywheel on, I have broken the wood drift key, I think. But at the moment, I don't have a pullet to get the flywheel off. So, I'm going to have to try find one and see what's going on there.

[00:37:18]Cool. So, I'm going to pop the rocker cover back on and check the valve spacing as well.

[00:37:38]So, I haven't put any gasket maker on here yet, and I haven't really fked anything down. I just want to fully assemble everything, turn the engine, and just make sure that everything is Cool. I'm going to try rotate rotate it and see if there are any issues.

[00:38:34]Hopefully it just rotates and there's no problems.

[00:38:50]Looking good.

[00:38:52]Very happy.

[00:38:56]I'm getting air blown in my face out of the spark plug hole, which means well I'm hoping the compression is decent and the new rings are doing their job.

[00:39:08]Awesome.

[00:39:12]Cool.

[00:39:14]I think that's going to be it for this video. Um, I'm going to check out the clutch in the next one. Make sure that's okay. Uh, talk everything down. Uh, maybe try neaten up the bike a little bit. Uh, put some new sort out the springs. Give it a coat of paint. Yeah, to see