Alternator Tensioner broke, engine locked. Balancer causing this?

[SuburbanCowboy]

2006 Concours, Engine has 30K miles on it. Had been running perfectly. Hit the starter button, engine barely turned over, it backfired a bit, then made a clunk and locked up. I feared hydro lock, but when I pulled the plugs, no fuel in them (Thankfully). after pulling the clutch side cover off, i see the alternator tension looked like it was broken. The little stick part of it came out of the little hole it is supposed to be in. Does this chain run the balancer? Is my balancer bound up with my crank? Do I have to disassemble to fix this?
This is the first Kawasaki I have owned in years, and it had been running perfectly the day before. I checked for bent rods, 1&4 and 2&3 are equal to each other. No fuel in the oil, no metal in the oil. The tensioner is the only thing I can see that isn't right.
I welcome any thoughts on this. I have been working on bikes and stuff my whole life, I just don't know THIS engine YET.

[Boomer]

The Balancer shaft is gear driven directly off of the crankshaft.
That chain has 2 functions.
1- When the engine is running it takes drive from the crankshaft to turn the Alternator.
2- When starting the engine it takes drive from the Starter motor to turn the crankshaft.

Since your engine backfired when starting, I suspect that may have allowed the admittedly crap alternator chain tensioner to come undone.
If the engine turns freely and you have checked the timing for the camshafts is correct, then my recommendation would be to fit Kwick's fix for the tensioner https://www.kwick.biz/product/tensioner-tamer-alternator-starter-chain-tensioner-fix/ and refit it all and see if it all works normally.
If you still cannot turn the crankshaft, then either the camchain is seized or something deeper in the engine is busted.

[SuburbanCowboy]

Valve train is free, timing is correct, chain is free. Pulled the oil pan, no metal flakes (or chunks). I guess I have to pull the engine apart.   I will install the tensioner repair kit after I figure out what is really wrong with this.

[Boomer]

Does the crank rotate ok now? I assume so, since you confirmed that the cam timing is correct.
If that is the case, then it was almost certainly the alternator chain tensioner that was preventing it from starting.
When it is flapping about, the tensioner can jam against the clutch.
However, if you want to remove and strip the motor, go for it.

[SuburbanCowboy]

The crank does NOT rotate. I have the oil pan pulled off and have not yet had a chance to look up in there very well. I imagine I will need to pull the head and engine IF I cannot see anything wedge inside the engine case.
I have been working on motorcycles for 40+ years. I have not worked on this engine before now. I was hoping someone here had an intimate knowledge of the inside of this engine and could suggest something that might suggest what is actually keeping the crank from turning. With the alternator chain and the cam chain removed, the crank will not turn. If I have to guess, I would say somehow something got ingested into the intake and is wedged in the head. If I cannot see anything in the crankcase tonight, the head is coming off. I will clean up the vales (lap them), and put on new valve seals while I have it apart.
I appreciate all suggestions here. Thanks!

[Boomer]

Ok, if the crank is not rotating in either direction and you have removed all of the clutch plates, then the most likely cause is going to be a jammed piston, probably due to a busted piston or sleeve.
If something got jammed between the gear teeth of the crank-balancer or crank-clutch basket, it would normally free up if you turned it the other way.
The only things connected to the crankshaft are the conrods, camchain, alternator chain, clutch basket and balancer shaft.


The C10 engine is pretty tough. My 86 did 50k miles WITH this damage to one of the sleeves.
I'd previously found the missing piece in the sump but had no idea where it had come from and the bike was running fine after I fixed the gearbox issues.

[zrx mitch]

Any pieces of the clutch pressure plate missing? Pieces can get into the crank/balancer teeth and lock it, can you rotate it reverse of normal direction?

[SuburbanCowboy]

Found it. Hydrolock for Win/lose. There was no fluid in the cylinder when I check it right away, but this rod sure is bent.
Thankfully I got it out from underneath without having to fully remove the engine. Boomer, those are some great photos, and it sure is nice to be in a group of people who REALLY know these machines. I am in a facebook group that wasn't too helpful. Though I am not thrilled at this outcome, I can fix it.
Anybody have an extra rod they want to sell?
Thanks again to all who responded.

[DC Concours]

Sorry to see this. I think those rods are balanced with each other when first installed.

[Freddy]

   Your measurements for bent rod couldn't have been accurate. 

Hope the fix goes well for you.

[Boomer]

No new conrods available from any Kawi dealer over here as K no longer stock them.
I have a few used conrods from early C10s (87 & 88), but I'm in the UK so probably cheaper to source from the USA.
Whatever you get, fit new conrod shell bushings/bearings.

Any damage to the bore or the piston itself?

[SuburbanCowboy]

Everything else looks fine. It's just a pain I didn't need at this time, but I will get it fixed. I was going to just use the bushings that were already on the conrod, but probably best to buy new. I don't have lots of money, so inexpensive fix is good, but not at the expense of another failure.

[Boomer]

The new bushes form themselves to the crankshaft & conrod so best to fit new ones, unless refitting the same conrod in the same position.
Once reassembled you will need to be gentle with her for 250 miles or so, so stay under 5000rpm.
I would also change the oil & filter again after maybe 500 miles.

[Stasch]

Anybody have an extra rod they want to sell?

This could have been the result of multiple hydrolock incidents.  (pics attached are of one I am sure had multiple incidents.)

Yours was no. 2 or 3 so its doable from the bottom with the engine still in the frame.

1 or 4 requires splitting cases to replace.

I have some K and L marked conrods, but you need to replace the conrod with one of the same weight. 

There is a weight letter designation printed across one side of the original conrod and the crank connector.

See attached pics - if you can't make out the letter, look up into your crankcase and find it on the other conrods.  I don't think the factory mixed and matched opposing pairs, but its possible to do so and still maintain the balance of your crank and pistons assembly.  I learned this from SISF.

The plain bearings also have a colored weight indicator somewhere on the edges of the bearing halves where they meet, indicating the size matched to the crank at the mfg.

I re-used the existing plain bearing halves in the replacement conrod / connector combo, verifying clearance with plasti-gage before committing.  It was in good condition and already seated into the crankshaft.

[Daytona_Mike]

Was it you that we asked if you checked your piston heights and you said they were fine?.. and  that  no way it was hydrolock...  Maybe it was someone else.

[SuburbanCowboy]

They were at Bottom dead center and as low as they could be. I could not measure a difference in height.   Good news is, I have the bike back together. I hope to have it running tonight. I have the tensioner mod and overflow tubes installed. Hopefully the bike will run for a long time. I learned some fun tricks for installing the throttle cables AFTER installing the carbs. Not the easy route, but not bad if you remove the cables from the throttle. Also NOT a good idea to NOT put all 4 carb boot springs on before installing the carbs.
That was really fun trying to get those hooked up. Once those carbs were in place, I didn't want to yank them. Many lessons learned with this bike.
Once again, I love how knowledgeable people are on this site. THANKS TO ALL WHO  HELPED!

[Boomer]

Fingers crossed for a successful first start. 

Difficult to check for hydro-lock when ya can't rotate the engine.
I always remove the throttle cables from the grip end before I remove the carbs.
Yes, springs on the carb boots BEFORE you fit the carbs. I feel for your scratched, bleeding fingers. <LOL>

[SuburbanCowboy]

She fired right up. Can't say I wasn't nervous. Put 20 miles on it. Seems fine. Thanks so much to all for the awesome help.

[Boomer]

She fired right up. Can't say I wasn't nervous. Put 20 miles on it. Seems fine. Thanks so much to all for the awesome help.

Whooop Whoop! :-) It's a lot of work, but damned satisfying when yer done and she runs good and smooth.