Seized Engine: 2014 Te310r W/ 15 Hours

**********EDIT TO ORIGINAL POST********

Based on findings when I removed the right and left side covers of the engine and head, I have discovered that the failure of the engine was completely my fault due to my negligence when working in the airbox of the bike. I allowed a small screw to fall into the airbox--which deflected into the intake--amazingly. The rest of the post details the diagnostics detailing the trouble shooting the piston seizure--and subsequent damage the screw caused as it worked its way into the combustion chamber. Rebuild overview follows as well.

Also, it should be noted, that I should have put a boroscope down the spark plug hole to look inside the combustion chamber as directed by Trench. That was sage advice as it turns out. Boroscope attachments for you smartphone will cost approximately USD$35.00.

Again, when dealing with a seizure, look into the combustion chamber first.

Also, all tools, debris, and screws/bolts dropped into the airbox or intake MUST be accounted for. They do not magically fall out of the airbox through the small cracks in the bottom. Lessons learned...Original post follows:



I have a 2014 TE310R with a seized engine.

(Yes. A 2104. Identical to the 2013 as far as I can tell.)

I am the second owner. Bike has about 10-15 hours. The bike is like new.

The power up mods were done. It started right up every-time. I rode the bike around the neighborhood since I bought it back in October.

Just putted around the neighborhood basically.

Then Sunday took it to the trails for some pretty flat, easy trail riding and it seized at the bottom of a dry stream bed. I was lugging it over rocks and it stopped.

Tried to hit the button several times—and each time I heard a “tink”, “tink” when the starter engaged.

So I tried to kick it. Kick lever was solid like it was welded on.

Absolutely seized.

Not missing any engine coolant.

Oil level and condition seems fine. (Not milky at all.)

Transmission will shift into 1, 2, and neutral. Didn’t try any other gears.

Bike will roll around in neutral fine.

Recommendations, please.

Thank you in advance.

-Mitch

My first guess is that you swallowed a valve.

But pull the right case to see if anything is going on. Then the left cover to see if the sprag is intact. (Especially if there was a kickback right before the "event")

Your bike looks insanely clean compared to my 450+ hour '14.

Is your capacitor off the throttle body or something?

Oops.... I see the battery lead is discontented so it looks like you're starting to dismantle. Nevermind.

Will do.

Thank you.

Questions about the sprag (Freewheel bearing Part # 8000 87289).

What does it do?

Answer: The Freewheel Bearing (a.k.a. Sprag or Clutch Bearings) acts as a break in transmission or clutch in one direction, but transmits rotation torque in the opposite direction.

Why is it in there?

Basically, to act as a clutch between the starter drive ring on the crankshaft and the worm gear on the starter. If it were not there and a regular bearing were in its place, the starter would have no way to transmit its rotational force to the crankshaft.


Why not just a normal bearing?

A normal bearing would just spin as the starter engages and would spin the worm gear, which would rotate freely with no way to transmit power to the crankshaft.

Yes, I pulled the starter in hopes that there was some kind of interference from that worm gear on the starter.

No such luck.

The sprag gear, or "free wheel" from the part manual, keeps coming up in conversations, discussing likely points of failure.

Just read the post:

"310 starter gear casing broken - need help please!
Discussion in '4 Stroke' started by Judgie, Oct 1"

Trench:

I killed the bike on a hill, and I believe it did roll backwards.

Forgot about that.

the sprag is a one-way device, allowing crankshaft to freely rotate in one direction. It applies torque to the inner flywheel (really- the ring gear) if it is moving faster in that same direction (via electric start, or also if the engine happens to go backwards). Helicopters and lotsa small engine starters use 'em.

The pawls or dogs or dogbones in the sprag could be messed up or locked, and it would be hard to see without removing the flywheel. Very small fragments may be in the bottom of the side cover or stuck to the flywheel via magnetism. you could luck out and have a bad garter spring on the sprag.

look for small debris in the other side too, causing the crankshaft gear or clutch gear to lock.

look for scars or other evidence. put the bike in 3rd and roll it forward and backward gently to see if anything in these areas "fall out" or the pawls retract.

remove the spark plug to make turning the engine easier, and for inspection- especially if you have an endoscope (super cheap for smart phones $10-$50. recommended)

I'm also thinking broken valve. worst case scenario: broken/bent rod or crank.

was there some oil pump type failure in some early red head 310s?? how quick would it have seized.? anyway, good luck.

2011 te310 now at 277 hours (9660 kms)

oil pump failure: Not that I've heard of (250r/310r are the redheads here, right?) but I don't know how many red/blackheads xlites there are in the world- less than 10,000 I'd guess.

My 2013 TXC310R (BMW Red Head) shattered the oil pump drive gear in the middle of an XC race.....I never quit/death before DNF as the FahQ MC motto goes, so It ran hard racing and I mean hard due to my ongoing battle with Oscar "Sodas" about 40 minutes of wheel to wheel XC racing with grinding metallic sounds and very loud moving parts but I finished, Oscar pulled away from near the end and beat me , it was like 95 dgrees out and I was in O heat mode.
The motor was toast from top to bottom and filled with debris.
I brought it in a box disassembled to ZipTy Racing and they rebuilt it from bottom to top with every mod they had at the time. Still have love for those bikes but they were too delicate for me, I had many problems with mine, from FI to hard parts. And it sold me on going back to a carbureted 2 stroke!! May 2013 Race and already blew the engine....on a 2013 model machine.
It happened in this oak grove a sickening sound came from the motor while railing between the trees in these ribboned hairpins. BTW the course was most excellent as was my very expensive race that day. round the corner stand er up and hard on the gas. explode your oil pump drive gear. Fletchman will be proud of that woods riding form! hahahaha

Additional my sprag also failed they are very sensitive to and galling of the race or rollers, Kawasaki had a bulletin on some of their bikes- if the sprag surface had any visible marks it was cause for change....my husky one even looked ok to my eye until I showed my ace mech he said it was trash and for can be the cause of starter issues, it had barely perceptible ridges and roller marks, I mean stupid small and unfeelable with the finger nail test. we changed the entire sprag assy and my starter was back to normal again. I got a break, my dealer warranted it so zero cost. those days are gone now.

Ok, I'm boning up on this issue.

Found lots of conversations about this sprag being torn up due to popping the clutch to prevent rolling back--as was my mistake.

I have a KTM sprag coming; we'll see if it works.

And I bought a puller to get to flywheel off.

I'll keep you all posted.

Oh, another question:

When I pop the covers on both sides to inspect and to replace the sprag, will I need new gaskets?

Or will I be able to reuse?

Also, I have a 2014 TE310R, will it have the revised ring gears with hardened teeth?

Should I replace these while I'm there to prevent starter/worm gear/broken case issues?

I love the electric start.

Works great on mine.

I would recommend pulling the flywheel and inspecting your ring gear and sprag before buying one. The husky worm comes with a ring gear too, IIRC. replace both as a set, if needed. Gasket may be okay to reuse.

Confirm what the problem is before investing money and time.

The 2014 will have the updated stuff.

Also, I *think* (but do not know) that you can remove your sprag & ring and leave the worm in.... and have a kickstart-only bike. these bikes kickstart incredibly easy.

I have a KTM sprag coming; we'll see if it works.

Sprags are like any bearing they are identified by size and they are sourced products, mostly the Euro brands use various high quality sources of bearing manufacturers and label them with their OEM or sometimes not.

As long as your "KTM" sprag is the same dimensions it should be fine, and maybe from a better supplier than the BMW Husky one.

The worm gear (Husqvarna Part # 8539725 ) looks perfect as well as the starter ring gear.


View attachment 93640

Your worm/ring look okay. (but the pics of the ring teeth are slightly blurry). If you feel anything on the ring teeth, replace both. I don't see anything there to cause your motor to lock or seize.

So does the engine turn now? How did the old sprag look? did you try turning the engine when the sprag & ring were out?

also- what KTM sprag did you get? (and why?) Or did you get a husky sprag that will have a KTM logo on the package??

Trench:

I’ll circle back to the sprag in a bit.

Right now I’m trying to get the hub off.
But it’s super tight.
I’m using a lot of torque on the puller to pull the hub.

No dice.

The puller’s mandrel is deforming I’ve got so much pressure on it where it contacts the shaft—it’s actually mushroomed slightly.

I’ve tried tapping lightly on it as well with a small hammer. No movement.

Should I heat the hub?

Here's the step I'm on:



But the puller's center mandrel is deforming. I am applying a lot of torque I believe.
And, yet, there's no movement.