Topic: Motor Once Free, Now Stuck

[jrich44]

Spark plugs are out. Doesn't seem like the pistons are moving, the bolt is just tightening.

[jrich44]

No, the bolt wasn't loose when I started. I'll take the pressure off the valves and continue. Thanks for your help.

[jrich44]

Well I did not have a good day. The bolt finally just sheared in half. Luckily I had a screw extractor that was able to get the other half out of the engine.

So the engine is still stuck. I guess that means I'll be taking the engine out and taking it apart. I was going to do that anyway, but I wanted to see if it would start before I did too much.

Thanks again for everyone's help.

[grasscutter]

Well I did not have a good day. The bolt finally just sheared in half. Luckily I had a screw extractor that was able to get the other half out of the engine.

So the engine is still stuck. I guess that means I'll be taking the engine out and taking it apart. I was going to do that anyway, but I wanted to see if it would start before I did too much.

Thanks again for everyone's help.

Whoa there grasshopper!
Slow down.
Whoever said to go ahead and start cranking on that bolt as a solution to freeing a stuck engine is a fool.

Patience.  Its in your best interests to get the engine free, if at all possible, before tearing it apart.
You don't know if it needs torn down yet.  Sure...it may need torn down... but seems to me, we're in a 'cart before the horse' scenario.

So:
Keep the plugs out.
Keep putting whatever mixture or solution you prefer, down in the cylinders.
Keep bike on center stand.
Keep bike in 4th or 5th gear.
And keep rocking the rear wheel back and forth.
(or do the same thing rolling it back and forth on the concrete.  Your choice.)

If you expect a stuck engine to free itself on your 1st try, you are mistaken.
Sure, sometimes it happens, but not usually.
And...if your in that big of a hurry...fixing this bike, might not be your cup of tea.

Follow those steps and report back in a few weeks or whenever you get it broke loose.

Cheers.

[AbbyRider]

Some possible reasons for stuck engine:

Seized piston(s)
Seized up crankshaft bearings.
Seized rod bearings.
Seized transmission.
Seized clutch.
Seized kickstarter gears.
Seized electric starter, gear train and or starter clutch.

Seems weird that the pistons would be stuck like that if things had been moving a few months back, especially if you were able to crank the kickstart gear by hand. I've unstuck pistons that were more or less rusted to the cylinder, and the bike in your pic looks in decent shape. And same goes for the bearings. So you can probably skip down to the transmission. When you were trying to turn the crankshaft bolt, did you try doing it with the clutch in? If it turns with the clutch in then the problem is with your mainshaft gears. If it's still not turning then keep investigating. You can pull a lot off the engine for inspection without taking it out and splitting it. I've just gone through that, and you want to avoid unnecessary work if possible.

[Kickstart]

+1 on both AbbyRider and grasscutter's posts

Also, there has to be more to this bike's story.  It just doesn't make sense that you were able to crank it by hand over the summer and now it's seized.

• Was the bike really kept in the garage (not outside in the rain with plugs out our carbs off?) - If it really was garage kept, I think it's highly unlikely your pistons are seized.
• Tell us more about the time when you were last able to crank it.  Did you just crank the kickstart lever once/twice, or did you do it a bunch of times to confirm the engine successfully made more than two full revolutions?
• What else was done to the bike?  i.e. adjust the tappets, cam chain tensioner, changed spark plugs, changed the oil - anything... tell us even if you don't think it's related.

[Phoenix]

Bad news maybe.  Mine was in a shed for twenty six years.  It turned over.  After a month or two of working on it and some time with the carbs off and not plugged, all of a sudden it's seized.  I tried all the fixes that have been mentioned and nothing worked.  Had to take out the engine and work pretty hard to get the jugs off.  If you go that way, I suggest a frame kit.  When you put the engine back in, the head needs to be re-torqued after 500 miles.  That's where I am now without the frame kit so I'll be talking to Frank about one.  Good luck!

[jrich44]

I am really starting to think it's something other than the pistons seized. It's been too cold here to work on it the last couple days (hasn't been above zero here in ND for a while). So in the meantime let me explain all the history I know of the bike.

I bought it over the summer of 2013 after checking that the engine turned over with the kickstarter a few times and seeing it was stored with clean oil. Loaded it on a trailer and stored in my garage in MN until December. Put it in another trailer to move out to ND in December and has been stored in another garage here since then. All the moves were done with the fully assembled bike, spark plugs, carbs, etc.

How can I determine if the problem is in the transmission? Like I mentioned earlier, the clutch is still a little sticky yet, but I am able to easily shift through all gears without using the clutch. Also, all gears seem to engage well and neutral rolls smoothly. When I was wrenching on that rotor set bolt (a new one should be in the mail on Thursday by the way) the bike was in neutral and the bolt did not want to rotate.

Other things I have done that may be involved, except all these were done after it was stuck:
- Changed the oil/filter (oil looked good)
- Changed spark plugs, then took them out
- Took off carbs for cleaning
- Dropped the oil pan (no metal shavings found)
- Loosened the tappets to relieve spring pressure

[Kickstart]

Man, this is a tough one...

What do you mean by the clutch being a little sticky?
Try adjusting the clutch (as per the manual - taking off chrome plate behind the kick start lever) - and see if that does anything (I don't think it will, but it's worth trying).

When it's in neutral, does the neutral light go on?

[jrich44]

Man, this is a tough one...

What do you mean by the clutch being a little sticky?
Try adjusting the clutch (as per the manual - taking off chrome plate behind the kick start lever) - and see if that does anything (I don't think it will, but it's worth trying).

When it's in neutral, does the neutral light go on?

By sticky clutch I mean that when I pull the lever in it only disengagaes the clutch partially, I can still feel some resistance when rolling the bike in gear. I'll work on adjusting the clutch and get back to you.

I'll also hook up the battery again and look for the neutral light.

Thanks so much for everyone's help. I hope to start a build thread soon if I can make some headway.

[Doggie]

I just came from my garage where I had the same problem with my CB550 engine. Seized up. I went to take the cam out, but couldn't because of I couldn't turn the engine to get to the 2 bolts. I took the left cover off to try to turn the engine, no luck. I went back and forth a few times and then it freed up. Took the head off and the engine turns freely. I suspect that the cam chain jammed do to being loose. One side of the came bearings are worn do to no oil. There are no groove and oil hole on those 2. Factory defect?
                                                  Doug

[Doggie]

I see now that the cam bearings are so worn that the groove is gone and the oil hole was plugged up. Time for a new head.

                                     Doug

[jrich44]

This evening I was able to work on the bike a little more. I first hooked up a battery, and the neutral light does come on when in neutral. Next I adjusted the clutch, which didn't seem to affect anything. After sitting a few days longer with Acetone/ATF the engine is still locked up the same.

I am really doubting the cylinders are seized, but I think there is something jammed in the transmission. Is there any way I can diagnose anything else with the engine still in the frame? Are there any engine covers I can pull off to view any other areas that may be stuck? Or is my next task to remove the engine for disassembly?

[Kickstart]

Well, I don't know.

But, I don't think there's anything jammed in the transmission. 
Since the wheel spins when you pull the clutch in, it tells me everything is spinning in the transmission.

I would guess that the problem is somewhere upstream of the primary drive sprockets.
So somewhere between the head, cylinder, rods, crank, and primary chains.

It's possible the cylinders are seized.  Maybe you'll get lucky and they'll free up after soaking longer.
If not, I'm thinking you need to take the engine out and open it up to see what's wrong.

Maybe others have better suggestions.

[grasscutter]

I want to see a video of the bike on the center stand, in 5th gear and you trying to spin the rear wheel by hand.
Would like to see the level of effort you are putting into spinning the wheel.
You need to put serious muscle behind it.
Back and forth.
Frontwards, backwards.
Hard!
Stuck pistons can be quite stuck

Think about when you go to bump start a bike that already runs. 
You push it down the street as fast as you can, jump on, dump it quick in 2nd or whatever gear you can quickly get it in, and still the tire will skid as it gets the engine to start turning over.
And this is with a bike that already runs!!

So keep that picture in mind, when you grab that wheel and start slamming it back and forth getting the engine loosened up. 

Muscles!  Get after it. 

Id also like to see if there truly is 'no' movement, or just a 'little' movement.
You can take off the valve covers and see if any of the valve train is moving.  Even if its tiny tiny amounts of movement.  It will help track down what is actually stuck.

Where do you live?
You don't happen to live near salt water do you? 
After changing the oil, did you start the bike?
Has it ever been started by you?

[HondaMan]

This evening I was able to work on the bike a little more. I first hooked up a battery, and the neutral light does come on when in neutral. Next I adjusted the clutch, which didn't seem to affect anything. After sitting a few days longer with Acetone/ATF the engine is still locked up the same.

I am really doubting the cylinders are seized, but I think there is something jammed in the transmission. Is there any way I can diagnose anything else with the engine still in the frame? Are there any engine covers I can pull off to view any other areas that may be stuck? Or is my next task to remove the engine for disassembly?

If you can shift through the gears by hand, the tranny is not stuck. The clutch drag you're describing is normal, as these are wet clutches. They never spin freely. When well wetted in operation, the oil lets them slip when the lever is pulled in, but they are never drag-free like a dry clutch.

This sure sounds like [a] stuck piston, or piston ring. It takes little in the way of water to rust a bore, and not much rust to make them stick. The clearances are very small, like .001" to the cylinder walls from the piston skirts, and of course 0" between rings and walls.

[Terry in Australia]

Are the carbs still off mate? If so, remove the cam chain tensioner and stick your finger in the hole to check if the cam chain is still where it should be, or whether it's broken and dropped into the lower case and wrapped itself around the crank. That'll certainly lock up your engine. Cheers, Terry.

[jrich44]

I got out to the garage this morning to follow up with a few of you.

Grasscutter:
I didn't take a video because it's so damn cold here (4 degrees Fahrenheit) and my garage isn't heated. But I'll try to answer you question about putting some muscle into it. When the bike is on the center stand and in 5th gear I can yank up on the rear wheel until I lift the whole bike off the ground and I can push down until the front wheel comes off the ground. I think it's safe to say it's pretty stuck. And for your other question about living near salt water, no, far from it in ND (hence the cold). And no, I have never started this bike. When I bought it over the summer it had no key, no battery, etc.

HondaMan:
I'll keep filling the cylinders with ATF/Acetone if you think they are indeed seized. It can't hurt anything if that's not it. I love your book by the way, thank you for providing that!

Terry:
The carbs are still off so I went out there this morning and pulled off the cam chain tensioner housing. The chain is still in position, when I poke it with my finger I can wiggle it side to side maybe 1/8" or so. Am I correct in assuming it should have no tension when the tensioner is removed like it was?

I think what I will do for the rest of this winter is just work on the rest of the bike and wait till spring to do anything more about that engine. Maybe it is the cold that is giving me all the trouble.

[grasscutter]

jrich44... Yeah, can totally understand about not wanting to go out to an unheated shop to try working on a bike.
Not fun!

Am off the strong opinion based on what you said that the engine did fully and smooth turn over when you first got it:
That being said, am also agreeing with Hondamans belief that its stuck rings.  They can stick HARD!

You mentioned "When the bike is on the center stand and in 5th gear I can yank up on the rear wheel until I lift the whole bike off the ground and I can push down until the front wheel comes off the ground. I think it's safe to say it's pretty stuck. "

What you've described is not what I have in mind at all.
You know the difference between trying to twist a screwdriver handle with all your might, trying to loosen a stuck screw, right?
What about if you use an impact screwdriver?

Approach it with that same principle when you grab the rear wheel in 5th gear, and try to spin it.
Lift the bike up, is like trying to turn a stuck screw with a regular screwdriver.

Now taking the wheel and slamming it hard, back and forth, you are applying the principles of the impact screwdriver.

And no worries about breaking anything. 
You got to get the rust on the rings broke free.
It's going to take some patience.

Hope you get it broke loose soon.
Rust never sleeps!