Author Topic: Was given a CB650. Is it seized? (Read 2792 times)

Msh5337 · « **on:** January 16, 2017, 04:35:40 pm »

So I was just given an 81 CB650. No keys, no title, no gas tank or seat. And by the looks of it, it's been sitting outside for years. I don't really have a lot of hope for it, but I figure I'd at least give it a shot at getting it running. The first problem is that I can't move it. Either I can't find neutral, or its locked up completely. Even when I pull the clutch in, the bike won't roll. Just a few inches back and forth. Does this mean that the engine is seized up?

754 · « **Reply #1 on:** January 16, 2017, 04:39:50 pm »

Jack it off the ground, one end at a time, see if the brakes are stuck..

Msh5337 · « **Reply #2 on:** January 16, 2017, 05:15:31 pm »

No, it's def not the brakes. I can put it on the center stand and shift through all the gears. In each different gear, the rear wheel moves a little more or less. Shouldn't I be able to turn the engine by the rear wheel, when it's in top gear?

sixthwisconsin · « **Reply #3 on:** January 16, 2017, 05:31:43 pm »

Probably time to pull the plugs and spray lube in the plug holes. I have had good luck with a 10 sec spray of WD40 in each hole and let it sit. Rock back & forth and see if it has freed up. If not, try again. There are many concoctions of lube to use. For real stuck pistons, some use ATF/acetone mixture but I think you are moving the engine a little it sounds like so the WD40 may do the trick.

calj737 · « **Reply #4 on:** January 16, 2017, 05:43:28 pm »

If pulling the clutch doesn't allow the bike to roll, and you can't find neutral, probably the clutch plates are locked up. Is there any oil in the motor? Pull the dipstick and inspect it.

If the bike has sat outdoors for that long, it's bound to be rusted up internally, though not unrecoverable. Pull the plugs, drizzle a mixture of 50/50 Acetone and ATF and let it soak. Same for the clutch. Drain the oil from the pan, then see if it will get unstuck.

Msh5337 · « **Reply #5 on:** January 16, 2017, 06:39:28 pm »

Yeah, that's what I was planning on doing next. The bike obviously didn't come with the original spark plug tool, so I have to find a way to get the two inner ones out. Supposedly it's a real PITA on these 650s. Yeah, there was a little oil on the dipstick, not too much though.

BomberMann650 · « **Reply #6 on:** January 16, 2017, 07:21:48 pm »

Did the 650's have a kick starter?

Chain hasn't bound up under the sprocket cover has it?

Msh5337 · « **Reply #7 on:** January 16, 2017, 07:31:47 pm »

No, unfortunately they don't have kick starts. Would make it a heck of a lot easier if they did. I was hoping that was the case, but I don't think so. I took the sprocket cover off and both the sprocket and chain are extremely rusty. I don't think they're seized together though.

754 · « **Reply #8 on:** January 16, 2017, 08:09:10 pm »

Is the aircleaner on or off...
If its off higher likelyhood of seizing..
Also drain the oil, and check for water....
I had a few with water, one real bad, must have been near a sprinkler, it had a lot.m

Msh5337 · « **Reply #9 on:** January 16, 2017, 08:30:40 pm »

Yeah the stock air box and carbs are both on the bike. That's why I figured I might have some luck with it. Plus the odometer only reads 2,000 miles, and judging by how clean some of the parts are, I think that's accurate. No, I haven't drained the oil yet, but I will do so tomorrow. I'm still holding out hope for this little fella.

ekpent · « **Reply #10 on:** January 16, 2017, 11:05:26 pm »

Is the drive chain so rusty it won't roll ??

Msh5337 · « **Reply #11 on:** January 17, 2017, 12:59:37 pm »

No, the drive chain is rusty, but not enough to keep it from rolling.

Quote from: calj737 on January 16, 2017, 05:43:28 pm

If pulling the clutch doesn't allow the bike to roll, and you can't find neutral, probably the clutch plates are locked up. Is there any oil in the motor? Pull the dipstick and inspect it.

If the bike has sat outdoors for that long, it's bound to be rusted up internally, though not unrecoverable. Pull the plugs, drizzle a mixture of 50/50 Acetone and ATF and let it soak. Same for the clutch. Drain the oil from the pan, then see if it will get unstuck.

I think Calj is right, I think the clutch plates are stuck together as well. I know that I'm in neutral, but the bike just won't move. How much of the 50/50 mixture do I use for the clutch. All the way up to the dipstick? I also came across this on YouTube last night. Has anyone seen or used this method before?

ekpent · « **Reply #12 on:** January 17, 2017, 01:15:17 pm »

The 50/50 mix is poured down the spark plug holes to try and release seized pistons. If the clutch is seized the way to deal with that is to remove the clutch cover and take the plates out not pour it into the crankcase, or at least I wouldn't. One would think the bike would still roll in neutral even if the clutch was seized.

calj737 · « **Reply #13 on:** January 17, 2017, 01:20:20 pm »

Quote from: ekpent on January 17, 2017, 01:15:17 pm

One would think the bike would still roll in neutral even if the clutch was seized.

Why would it roll if the clutch were engaged, effectively putting it in gear? If pulling the clutch with the transmission in Neutral doesn't allow the rear wheel to spin freely, then the clutch plates (or other internal components) are binding up.

If they're that stuck, pouring ATF/Acetone may free them up, but it will probably necessitate replacing the discs. Won't know until you try. Once they're free, drain the oil and replace it and the filter with regular motor oil (and expect to do so again shortly after running the engine).

jonda500 · « **Reply #14 on:** January 17, 2017, 02:33:26 pm »

Quote from: ekpent on January 17, 2017, 01:15:17 pm

The bike would still roll in neutral even if the clutch was seized.

+1

Airborne 82nd · « **Reply #15 on:** January 17, 2017, 04:02:59 pm »

Quote from: Msh5337 on January 17, 2017, 12:59:37 pm

No, the drive chain is rusty, but not enough to keep it from rolling.

Quote from: calj737 on January 16, 2017, 05:43:28 pm
If pulling the clutch doesn't allow the bike to roll, and you can't find neutral, probably the clutch plates are locked up. Is there any oil in the motor? Pull the dipstick and inspect it.

If the bike has sat outdoors for that long, it's bound to be rusted up internally, though not unrecoverable. Pull the plugs, drizzle a mixture of 50/50 Acetone and ATF and let it soak. Same for the clutch. Drain the oil from the pan, then see if it will get unstuck.

I think Calj is right, I think the clutch plates are stuck together as well. I know that I'm in neutral, but the bike just won't move. How much of the 50/50 mixture do I use for the clutch. All the way up to the dipstick? I also came across this on YouTube last night. Has anyone seen or used this method before?

That youtube cracks me up I could not watch it after minute 2:14

I kept seeing a cig over a red can

Msh5337 · « **Reply #16 on:** January 17, 2017, 04:29:13 pm »

Quote from: Airborne 82nd on January 17, 2017, 04:02:59 pm

That youtube cracks me up I could not watch it after minute 2:14 I kept seeing a cig over a red can

It's great isn't it?! Lol. All of his videos are like that. He's gonna end up killing himself.

But I'm more confused now than before I started this thread. So if the clutch plates are seized, the bike will or will not roll while in neutral? Anyone else?

calj737 · « **Reply #17 on:** January 17, 2017, 06:33:30 pm »

It should roll in Neutral. But how do you confirm you're in neutral without being able to roll the back wheel? Clicking the shifter is no guarantee of the transmission moving. And you don't really know what gear the bike was in when stopped, and shifting completely up through all the gears without the rear wheel moving is very hard to do.

If you remove the dipstick, you should be able to peer into the clutch basket and see the plates. Operate the clutch lever and see if the plates move. Worst case, pull that cover and inspect visually/physically.

ekpent · « **Reply #18 on:** January 17, 2017, 07:45:47 pm »

Not uncommon for cb750 clutch plates to stick after sitting,sometimes for as little as a winter. Usually easily break free after starting up the engine and moving some warm oil around with the clutch handle tied back. No problem though still rolling them around in neutral or shifting them into gear.
Sounds like that 650 has maybe seen its better days for an easy start up, sound more like it might need a strip down. You said it would move a few inches back and forth can you feel and hear the shift lever engaging gears. Neutral is usually pretty easy to feel.

Msh5337 · « **Reply #19 on:** January 17, 2017, 08:22:58 pm »

Yes, I can see the clutch plates move when the lever is pulled.

And yeah, I can definitely tell that it's shifting through all the gears. The rear wheel moves a few inches forward and back in each gear, and some gears allow the rear wheel to move a bit further than others. Now here's something weird. When I'm in a gear and move the wheel until it comes to a stop, the clutch basket shakes. I'm able to move the wheel a tiny bit more after that, but it's very though. Now if I'm in neutral and move the wheel back and forth, it comes to a sudden stop and won't budge after that. And the clutch basket doesn't shake at all. Not sure if that helps or not. But yeah, I think I'd better just pull the cover and have a look.

jgger · « **Reply #20 on:** January 17, 2017, 10:41:00 pm »

I had a 650 single that was doing the same thing. It was a junker and lived outside for a long time. I thought the chain was rusted to the shape of the sprocket, so I cut it off and it still wouldn't roll. Got it to move a few inches each direction like yours. Finally figured the rear brake was binding and removed the rear wheel. The shoes were stuck to the drum and starting to break apart. It would stop rotating when the piece of brake material that was stuck to the drum would hit the piece that was still on the shoe. Took a chisel to it to clean off the debris from the drum, threw it back together and sold it!

754 · « **Reply #21 on:** January 17, 2017, 11:15:05 pm »

Just take the left front engine cover off,may have oil behind it..
Then put a socket on the crank , see it it moves. .two things you need to know at this point,
1 Is it seized?
2. Is it sitting with water in the oil..?

Water in the oil, easy to check.. Take drain plug off bottom with a pan under it..water will be first to come out if uts in there..

Msh5337 · « **Reply #22 on:** January 18, 2017, 04:50:40 pm »

It's not seized!!!!!!! Took a wrench to the crankshaft and the engine turned smooth as butter. You're right 754, I should've done that from the very beginning. It's definitely something binding up the rear wheel. Might be the exact same thing that happened to jgger. But that's another day and another thread. Thanks everyone for your help! I need to learn not to question y'all.

BomberMann650 · « **Reply #23 on:** January 18, 2017, 05:14:42 pm »

Sweet! wheel rebuilds are cheaper than engine rebuilds and the bike was free!

bill440cars · « **Reply #24 on:** January 18, 2017, 05:18:39 pm »

Quote from: BomberMann650 on January 18, 2017, 05:14:42 pm

Sweet! wheel rebuilds are cheaper than engine rebuilds and the bike was free!

I guess I have been lucky. I have had to cut the drive chain or work to free up the wheels, when brakes stick Remove calipers or remove rear wheels, to release the brake shoes. But haven't had an internal problem, like the clutch sticking, that would keep one from being moved.

Good Luck with getting the problem taken care of.

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Author Topic: Was given a CB650. Is it seized? (Read 2792 times)