Engine Seized! Can I Get This Cult Classic Honda Running?

In 1977, Honda released a motorcycle that would change their company forever. So when I saw one at the local auction house, I just had to buy it, the Honda CX500. In the last 46 years since this bike was released, it has gained a huge cult following. But I bet there's a lot of cool stuff about this model that you don't know, and I'm gonna go over that today while we try to get it running. Now I bought this bike sight unseen, other than a couple small pictures online from the local auction house, and I knew two things about it. One, it had a title, and two, it's not a Honda Shadow. This is the CX500. So we went and picked up the bike, brought it back to the shop. Now let's take an inventory and see exactly what we have. So it looks like our front brake is not working. That's just a mess. And we got a bunch of wires hanging out here. But we do have a decently straight front fender. There's a dent there, I guess it's not perfect. I should have never touched it, I would have never found it. Oh, now it's gonna bother you forever. Yeah. These bikes ran a single front disc on the front and Comstar wheels. So while the Comstar wheel was released in 1977 on the Honda CB400 Dream 750 and maybe the 250, the CX500 was the first production bike to run a specifically designed tire to be tubeless. These Comstar wheels were known for giving you the flex of a traditional spoke wheel while allowing the tire to go tubeless. Okay, moving on, it looks like we have a horrible fairing. But check this out. We have a Craig head unit. Who knew? That right there was worth the price of admission. Okay, so we have a super jank broken up fairing. That's gonna be the first thing to go. Looks like we have ourselves a nice rat's nest of a electrical system going on here. That'll be fun. Got some like 12, three Romex wire. That was probably the speaker wire for the big subwoofers powered by the Craig head unit. Likes his woofing. Our bars look straight with 28,600 miles. Our gauges look good. We're missing a key. That's neat. Choke cable seems a little stuck. Front master cylinder, that mirror's broke. Our throttle's stuck. That's neat. Now this is one of those things that us bikers will probably never understand why they did it, but they did it. The gas cap is connected to a chain. So kind of wherever you, when you stop for gas, I guess maybe you could set it there. But it just seems like, you know, if this bike's brand new, you don't wanna be putting your gas cap, you know. Maybe you do that. What's wrong with doing that? Well, cause you don't wanna set it on your, On your tank? On your tank. Ooh, maybe you just set it right there. Look, there's a little slot for it. Right there. There you go. Okay. I still don't like it. Ooh, let's see what's in the tank. Doesn't look too bad. Oh, it's not horrible. Oh shucks, there's even some gas in there. Well, dog gone. And it doesn't smell putrid. Oh, that's a thing. Our tank is nice. Happy with the way it looks inside. The seat is, you know, pretty much like you'd expect. Big old sissy bar hanging off the back. This is not the correct taillight for this bike. And it probably broke whenever this here happened. This taillight should be a big half moon Honda taillight. Shoop. So that's not right. So what's really cool about this motorcycle and why it changed Honda as a company forever is because of the engine. This is the first V-twin that Honda ever produced. This is an 80 degree V-twin. And it was kind of modeled after the Moto Guzzi's. Honda just couldn't leave well enough alone with the engineering. So of course they took it to the next level. This bike is water cooled. And the transmission is actually mounted here underneath the crankshaft instead of a unit behind the engine. Now this is a five speed transmission. But one of the really cool things about it is it spins opposite of the engine. And that's to help counteract the torque that the engine produces. Another thing with this bike is we have the electric starter here. Now this was an electric start only bike. And back in the early 70s and 80s, that was a little uncommon. Most motorcycles of that era would at least give you the kick start backup option. This one did not. This is electric start only. So we have a nice sissy bar. And turn signal. We have both side covers. I didn't take them off to see what's underneath them. No, no, no, no. Hey, maybe we don't need a key. Look, they got this wired right into the coil. Ooh, that's funny. Okay, well that's there. We have the original megaphone. It's a side stand, center stand. Dual rear shocks. Preload adjustable only. Rear drum brake. And check this out. Look how small this axle is. Like that's a sleeve over the axle, but that just looks really small. Of course, our tire shot. Shaft drive. This was a thing back in the day, back in the early 70s and 80s. You know, they really marketed the shaft drive on some of these bikes because it smoothed things out. It was less maintenance. It was quieter, things like that. So that's cool. We can get shaft drive, the pegs. What do you think's under this cover, Dan? Oh, you got a turn signal flasher. Air box. Looks nice. Well, yeah, this doesn't work. So those carbs are coming off. Of course, front brake is nil. Fork seals are leaky as can be. We have a bunch of boot laces here holding stuff on. Check this out. This is the clutch. Clutch cable comes down here. And right here's the clutch cover. Right next to the oil filter. Oh shoot, there's a dent in the tank. I didn't see that. Darn it. Probably wouldn't have bought it if you'd known that. I didn't see that from the other side. Okay. All in all though, I think we have ourselves a pretty solid start here. The bones are good. It's got some cool things like the Comstar wheels and that's about it. Seat, does the seat? That answer your question? Yup. Do you know what we do? Check. Let's take this fairing off before we get Tetanus. I don't think Tetanus is the only thing that fairing's carrying. Okay, so this is just being held on with a boot lace because this mount's broken. Oh, look, they got some Romex holding it on here too. So that side there should just come off. Romex wire and some shoestring. It's holding this on. Oh, they watched our last video. Our Redneck Fixes video. You won. What do you think? Can we get three through there? What's this side? Oh man, why couldn't this side be broken too? Tell you what, Dan, we can do this really quick. Uh-oh. I think there's perfectly good bolts you could be unscrewing. Craig, you're a hazard to my health. Yeah, for sure. Where's my safety glasses? There we go. Well, we're done now. I'm still putting them on, all right? Oh! You okay? Yeah, I should probably start wearing safety goggles. Oh, wow. Oh, anything in here? Leaves, probably a squirrel. Honda. Okay, what's holding this thing here now? Oh, here. We're gonna cut this lamp wire. Let's see, we're gonna cut the boot lace. Gonna cut the direct burial Romex. I don't know if that's not direct burial or not. I'm not an electrician. Oh, there's a zip tie. What's that zip tie holding? Oh, here, okay. So we have another boot lace up top here. Here, now things will happen. Yeah, there we go. Are we off? We're off. Whoa. There it goes. It's free. Looks like a whole new motorcycle. Wow. Well, now we can see what's going on here. Oh, this is always fun when you see this stuff. That's neat. We got more of that here. Oh man, look. This had lamp wire, boot lace, wash line, and baler wire. Yo, what arts and crafts material wasn't this bike held together with? A lot of different mediums holding this stuff on. Bye, shadow fairing. I'm generally not that destructive, but that thing was garbage. I'm a shop, so I don't feel bad. This is looking better already. How easy is this tank? Come off. Pretty easy, apparently. I think we need to see if it is free. We need to, let's pull the spark plugs. Oh, look, the antenna came off. Dan, do you ever take fencing? And then I'll beat you. That now beats me. Dan, blink twice if you're not safe. All right, now that we have things stripped down a little bit and we can see what's going on, I think first step is we're gonna pull the plugs. We're gonna get some juice down in there. Then we're gonna pull the battery and get some volts. We need to see if this engine is free is what we need to do. I don't know why it wouldn't be, but no sense trying to get it running if it's not. So let's do that. You know what? Those are tight. See if we can get a little juice in there. It's not good when you need penetrating oil just to get the spark plugs out. Crank this one. Okay, that one's coming out nice. If we break a spark plug off, this is gonna be a really short video. Okay, we're gonna make a little concoction here, Dan. ATF. 50% ATF and half acetone. A mixture of half ATF and half acetone makes a really good penetrating fluid. Stay tuned. More chemistry with Craig. Well, that's penetrating everything else. Yeah, I forgot there was a drain hole there. Okay, it's loosening it up. Look, just let that sit for, what was that, a minute? And I'm just working it back and forth, back and forth. So the dissimilar metals between the spark plug and the cylinder where it threads in, you know, is a known spot for corrosion and things like that. So I wanna take this easy getting this plug out. Because like I said, if we break the plug off in here, that's a nightmare. There. Look, yeah, nice. Well, it doesn't look horrible. Okay, now the plugs are out. We're gonna put some more of this homebrew penetrating oil down into the cylinders. Let that soak while we're doing some other stuff. And just, you know, if any of the rings are a little sticky or whatever, just kind of help lubricate everything as we go. Gurgle, gurgle. Okay, well, we'll just let that soak in there. Let's pull the battery. Neutral. Second. Third. Fourth. Fifth. It should be moving. At fifth gear? Yeah, fifth gear is your least resistance. The engine's seized. Could be. All right, I won't lie. I'm totally surprised that the engine's seized. I did not see that coming. So I have the cylinder soaking. Dan and I are gonna go grab a cheeseburger while that marinades. We went and got a cheeseburger and the engine's still locked up. So that didn't fix itself yet. Okay, so I think next step, what I'm gonna do is I'm gonna pull the starter. I'm gonna drop the oil and I'm going to pull this clutch cover off and see if the clutch is stuck and start eliminating some things here. And we're gonna get this engine and turn over so we can get this bike to run. I'm gonna start by pulling the starter just in case something stupid happened and this starter is froze up and it stayed engaged or something dumb. And that would prevent the engine from spinning over. Okay, well, that didn't do anything. So let's drop the oil. This is getting to be a little more than I thought it was gonna be. I really didn't see this coming. Good thing we didn't try doing this in the parking lot. We've done worse. We've done worse, you're right. We freed up one seized engine. We'll do it again. Coming out the exhaust. What on earth? Did I just get it to make a full revolution? Dude, did you just get through it? Yep. Just had to work it back and forth a little. Whoa, whoa, whoa, whoa! Oh boy. What? Is that oil the best? Looks a little watery. That's bad. Just pull the filter too. Yeah, that's not good. That's just sludge. Okay, so we know, or I think at least I know, we don't have any sort of problem between the rear wheel through the transmission. It seems like our problem is either, like I said, the engine's stuck, maybe valve's stuck. Let's pull this clutch cover next and see what we see in there. I'm getting some interesting smells. Can you describe them for us? Burnt. There it goes. Man, this is turning into quite the project. These all go a little bit at a time so that you don't put too much spring force on just one. Okay, I think it's moving. Nut, and then washer, then pressure plate. Okay, so there we have a clutch. Yeah, you never wanna see rust on your clutch plates like that. Can it be salvaged? You were gonna right there. Anything can be salvaged. He's gotta put enough money into it. Now, is that spinning? Yeah, it's spinning. Okay. Oh, look, look, look, look. I think I just found something. Okay, this might help. There's a bolt here for the cover of this bolt cap. Let me take it off. In behind that, I'm thinking, is our crank nut. So hopefully I can get a socket on there and I can start hooking this thing back and forth and get this motor broke free. But while we're doing that, let's pop these valve covers off too. My goal here is to just take everything off so I can see what's going on and what could be stuck. And then just dump PB Blaster in all of it? Pretty much. Ooh, upper rocker arms, valves, valve springs. Same thing here. I'd be very concerned if it was very different assemblies. I'm gonna pull that little cover and see if that indeed is a nut for the crankshaft. Maybe this thing was sitting outside. There's a lot of leaves in places. She's nice and stuck. Let's see if we got any valve movement. That feels like it's moving. Squirting. Okay, so those seem free. I think we're just stuck in the pistons. I mean, does it just need to soak for more? Well, that certainly wouldn't hurt it. Cam chain's really loose too. In the early years, these engines were known for having a lot of cam chain tensioner issues. Now, a way to tell if your bike was fixed at the dealership if they went through the service bulletins and everything is there should be three little punch marks next to the VIN number on the bike. Let's see if our bike has the update kit and went through that process. Here's the VIN number. I am not seeing three punch marks. That's not them at the top? Here? Those rust marks? Yeah, those are three. Those look like three marks. That is three marks there, isn't it? Well, you know what? Maybe this was done. Unless he did it himself and he just punched it himself. It still seems like the cam chain is a little loose. Yeah, so do we just let this sit? Buy a cheap bike at the auction, they said. I don't know. I think maybe we just let this thing sit for a little bit yet. Craig, I'm sorry. I think that's the point we're at. All you can do is wait. Let the magic unseizing juices do their work. It might be where we're at. This motor is still tight as can be. So I think the next step, since these heads are so easy to take off, we're gonna pop off the heads and see what we see. What's the worst that can happen, right? I mean, it's already broke. Can't really break it anymore. Yeah, this looks pretty easy. Boom, boom, boom. Pull that off. Exhaust, drop that. Intake, track, boom. Rocker, boom. Push rods, out. Head, off. Seems pretty straightforward. Let's get it done. Hey look, it's the inside of an engine. Yeah, there it is. There it is. All right, we got the left head off. So I am gonna hit it with a two by four and a hammer. I'm gonna see if I can get things to start moving. And if not, then I'm gonna take off the right head and just keep going until we get something running or we have a motorcycle that's just completely in pieces. It's not moving at all. You're hitting a two by four. I am hitting the two by four. I'm splitting the two by four. It's tight. I'm not joking, it's tight. Well, there goes my board. Well, that's not working. What if I just do this? That thing is not budging, like at all. Rock solid. Oh yeah, oh yeah. That's the acetone ATF mixture that was sitting in the cylinder for the last forever. Good ATF, not the kind that's gonna come after us for our hammer. True. Oh, just filthy. This cylinder is nothing but rust, pure rust. Man, bike's turning into a parts bike pretty quick, but I'm gonna still wanna see if I can get this motor free. I do believe we have a stuck cylinder there. Yeah, that cylinder wall is nothing but rust. Yeah, these cylinders is all part of the block. Huh, interesting, yeah. I don't think this thing is gonna move until we do some drastic measures. Oh yeah, there's like a ring around that. Should we try hitting it? It's the worst that can happen. Where's my hitting stuff? Man, it almost looks like it moved a little. Yeah, it's moving, no way. Look, you can see where it was to where it is now. Look at that, it's moving, yes. Is it down the whole way? It's not down the whole way. Oh my gosh. All right, I think we can all agree that if this motor doesn't come apart and get completely redone, it's a parts bike. So everything we do from here on out is purely for the sake of entertainment. Dan, let's see if we can get this thing to run now. Yeah. Now I'm gonna take my ratchet, get this up there on that crank nut. Oh, yeah. Oh, did we come up now? Are we hitting that rust spot? Yes. Yeah? Yeah, we came up. Okay, so we need to get rid of that rust ring. That cylinder is smoked. Engine's free. Yeah, now we just need to get the bike running. I guess we just get to sanding. Oh man, look how that cleaned up. So pretty. Beautiful. Now, put my wrench on here again. There it goes. Now we're making complete revolutions. Look, now I can even do it by hand. Wow, Craig, we got it running. Yay! Okay, so our starter's locked up too. Yay! Keeps getting better. My starter persuader. Nope. Curious to see what's inside the starter, Dan? I am now. Now let's see what we'll do. Okay, this is a little sketch. Don't try this at home. That looks like a working starter. Yep. Now let's see if that will turn our engine over. Do it, Craig, do it, Craig, do it, Craig, do it. I'm doing it, I'm doing it. Do it, do it, do it, do it, do it. There it goes. That's a free engine. That is a free engine. What are the chances? No way. Yeah, dude. Seized engine. From seized engine to spark. Here, look. Broken starter, but we have spark? Here we go. Nice. So I hope I have everybody in the comments section coming along with me and understanding that this motor needs to come all the way apart in order for it to be right. And we can't really do any more damage than what was already done. So I think we put the heads back on, cinch them down without new head gaskets and throw some carb cleaner or something through these carbs and see if this thing will fire up. Fire it up. Yes. Woo. We just bolt them heads back down in there. I mean. We'll be fine. Yeah, we'll be fine. One of the really neat design features of this bike is these cylinder heads are turned at a 22 degree angle. And the reason they did that was to tuck the carburetors in a little bit so they weren't in the way of your legs. And it also brought the exhaust out in a way that made the bike look really, really cool. Way to go, Honda. Did I say I do have new head gaskets coming for this? I don't remember. I have new head gaskets coming for this, but for right now, I just want to see if I can get this thing to pop off. These heads are so easy. They come off in like 15, not even 15 minutes, 10 minutes. Not even 10 minutes, six minutes. Every O-ring, every seal, every gasket on this thing is shot. So this is what it's going to be here at the moment. Click. Perfect torque every time. Couldn't be any more almost perfect. Making headway. Turning junk bikes into slightly less junk bikes. Nice, nice, nice, nice, nice, nice. So we should probably put that stuff back on too. Put oil in it. No exhaust. We don't need no exhaust. We don't need no stinking exhaust. Should we just run it pipes out like that and not even put them into the muffler? Yeah. Yeah. Let's just do that. Okay. Thought that was going to be the answer. We don't want to put it into the muffler and then find out that the muffler is breaking. The muffler doesn't work. Yeah. Let's do clutch. So we can get oil back in this bike. You made a mess here, Dan. This motor is not clean on the inside. What a gem this bike is. Filthy on the outside, even more filthy on the inside. They sure don't give you a whole lot of wiggle room here. That is for sure. Not too worried about the rust on these plates at the moment because the bike's not a rider anyway. All I really want to do is get this thing kind of together so that I can put the cover on, has all the pieces in it and get this thing fired up. That's not going in far enough. That's not right. Sorry, Dan. This bike's a little finicky on the inside because everything's corroded and rusty and stuff. So the gear that the clutch basket rides on is actually a split gear. It's two gears. So you have your, say these are the gear teeth on the bottom, on the inside gear. And then there's a gear on top of it. And these are slightly, you know, if they were like this, the other gears would just slide right in, but they're spring loaded and they're just offset like this. So you need to get it into the first set of teeth and then turn it a little bit so it slides into the second set of teeth. And that just keeps tension on that clutch basket. The problem is it doesn't want to, those two gears on the inside, whatever allows them to slip like this and that spring in mechanism in there is all janked up. So I'm having trouble getting these to line up so I can get the clutch basket in all the way. It's a thing. There we go. I think I have to admit, this is the dirtiest I've ever put something back together. Sure is an easier way to do this, but there's where it's going to get tougher because now I'm on those splines. Did you get it? Yep. Oh yes. Dan was getting nervous. Yeah, I was getting tired. Getting tired? Getting tired of watching you pull on that thing. Gee dun dun. You're so uneasily impressed. All right. So then we have the washer and we have this nut. Let's put this in gear real quick. Where is it? There it is. You found it? You found the shifter valve. Yeah. How many degrees from firing up this bike are we? Three. Three degrees. There. I think I heard the torque wrench click. Good enough to see if we have any life in this thing. Do me a favor, give that clutch lever a squeeze. Cool. Thank you. Did that do anything? Yeah, you did a fantastic job. Did it do anything? Yeah, it moved. Yep. Okay, so the clutch lever works. Seemed like it worked. Cool. We got this yet. I was hammering on these pipes earlier, but I did it with a soft mallet and you know, they're about shot anyway. So I wasn't too worried about it. Ship shape. I don't know. Let's say here, you know, if you're just for funsies, see if this thing turns over. Now that everything's back together. It's shooting rust out of the exhaust pipe. So for anybody that just was on the fence on whether or not this thing needs some work, there you have it. That's exciting though. Dude, we are so close. All right. Now we have one more thing left to do before we try to start this bike. Clean up the table. Well, might as well wait till next time. All right, thanks for watching guys. Don't forget to like and subscribe. We got the table. Oh man. Look how separated that mixture is. Gross it is. You think that might be coolant instead of water? That's a little bit of everything. Yeah, there's some coolant in there. Oh. Some automatic transmission fluid. So there was just a mass of tone, some water. Which is brew going on in there. Absolutely my friend. Don't worry, Dan, I got this. I know. Oh, oil. We should put oil in it too, probably. Ah, see, you got my hopes up. How much oil do you think we should put in it? A quat. A cumquat. How many cumquats, Craig? 3,000. That's 3,000 times more than I thought it was. Glug, glug, glug, glug, glug, glug, glug, glug, glug. Ready to start this motorcycle? This is the moment of truth. Okay, here we go. Well, the throttle's stuck. Could be what's screwing us up. Is that the missing piece here? Could be. I do believe I should have maybe unstuck them when I had everything else off, but. Take two. There's a good chance we don't have much compression either in that one hole. I'm hearing it. Holy soup. I have spark all over everything over here. Yeah, I definitely have spark. It's sparking here too. Oh, what does that mean? Touch it. No. Dan, you're no fun. What, is it gonna feel fun? Yeah, it'll feel fuzzy. Where were we? That's tight. Everything's gonna be slippy now. Okay, and you claimed there was spark over here. You saw the angry pixies? I saw them, all right. I'm gonna try to free up this carb butterflies here a little bit by just arbitrarily spraying penetrating oil everywhere. Let's work that back and forth a little bit. I might be able to free this up. Okay, it's better than it was. It's getting better. One of the other things it could be, may not have a lot of compression, could have bad spark plug boots, and it's actually jumping from here. The spark is coming out of the spark plug cap and directly to the inside of the cylinder there. So yeah, there's a couple of things it could be. Keep spraying this and working this back and forth here a little bit. The other thing too, is we don't know what the slides are doing on the inside there. Let's give it another whack. Come on, come on, come on! Oh, geez. What was that? That was a starter. I let it run quite a bit there. So it's smelling different. It's smelling different. Our throttle's starting to work. Is it still pretty stuck? It's still pretty stuck, but all right. Come on. You want to start. I think it's getting worse. Yeah, it's not getting any better. Why is the starter doing that? I ran it a little long there and it got a little hot. And remember, the starter was locked up when we started this. Like, I had to put it in the vice and get it free, so a lot going on here. Let's try this again. It's kind of fire. Come on! Never gets old. It was for a split second, but it counted. Count it! Oh, yeah. I ain't done yet. Oh, okay. I get nervous putting my hand in there with all that starting fluid in there and it backfires through the carb and it'll go, my hand will be in there. That's not good. Any chance maybe the starter just needs a break? I mean, letting it cool down wouldn't hurt. Here, do you want me to hold the spray? No, I got it. Yo, my ears are ringing. Let's do that again. Can't kill the thing now. Well, that was a lot of fun. Like I said, this motor was so rusted up on the inside, it was shot anyway. It needed to come all the way apart and either get taken down for parts, but we made it run and that was the goal. Thanks for watching. Don't forget to like and subscribe. Dan's gonna put a video here and here. I know you're gonna love them. See you later.