Catastrophic stator unit failure

Bike: 2007 125SX. Motor/chassis has 200 hours on it, but the bearings and piston only have 50 or so.

Hey everyone!

So I'm hearing this funny noise coming from my SX today. I can't quite place it, neither could the local mechanic, so we decided to just ride it and see if it changed.

I rode it and not much later the left side stator cover exploded, throwing parts everywhere and ceasing the motor.

Well, the flywheel is held together by rivets. Looks like one of the rivets popped and it hit the timing sensor at umm full throttle... Which basically destroyed it and blasted off the side cover. In blasting off the cover it destroyed all the cover mounting places which means the left side engine case is destroyed. I don't have pix today, but I will sunday.

In my mind its a manufacturer defect, unless someone thinks otherwise. The bike is a 2007 so its probably not under warranty, but what do you guys think I should do? What I'm gong to do is;

- Call KTM USA and see what they can help me with

- Find a used engine casing somewhere (I need help with this)

- Buy the rest of the parts new so this might not happen again

Let me know if any of you have any thoughts on this, that would be great!

thanks

tye

Edited by tye1138

Youll be wasting your time calling ktm, remember its a race bike. I would try tke clasifieds here and ktmtalk and flebay for the case and cover.

the other thing that happened in the past with the 200Sx models was the left end of the crank would break off and do this too. So check the crank to be sure it wasnt letting go that led to the whole thing happening.

Call ktm hey if you have skype it's free, plus if you ask nicely I have had ktm replace parts on my 07 450sxf long after the usual warranty period. worth a call just tell them what happened without an attitude. the post you put up here would be perfect

check ktmtalk for used a guy has a 03 125sx case for $125 don't know if that'll interchange

check part number at elitektm.com

Thanks for the info guys.

How accurate do you think ktm-parts.com is in terms of pricing? I looked up all the parts I need and the final price was not bad, around $900 bux including shipping.

I might just pull the trigger on new parts because I might save money now, but buying old, worn out parts is going to force me to spend money later...

I am concerned that this flywheel explosion has damaged other parts of the motor, but we'll have to wait and see after we pull it apart. For the time being its all about ordering the parts so we have something to at least put the parts in.

I will call KTM corporate about this, but I haven't been able to find a phone number or even an e-mail contact. Does anyone have one?

thanks again

if you go to dex online in Amherst Ohio and do a search for ktm you'll get there number

Update! I was lucky and found a set of cases new for half price. So I'm good to go on the case at least. I now gotta track down a used stator and flywheel unit which shouldn't be that difficult to find considering they are the same over many generations...

I'd replace the crank and bearings while I was doing it.

Crank probably not, its a one-off custom KTM racing crank. We will measure it and determine if its damaged, but I highly doubt it.

All the bearings will be replaced for sure.

Bike: 2007 125SX. Motor/chassis has 200 hours on it, but the bearings and piston only have 50 or so.

Hey everyone!

So I'm hearing this funny noise coming from my SX today. I can't quite place it, neither could the local mechanic, so we decided to just ride it and see if it changed.

I rode it and not much later the left side stator cover exploded, throwing parts everywhere and ceasing the motor.

Well, the flywheel is held together by rivets. Looks like one of the rivets popped and it hit the timing sensor at umm full throttle... Which basically destroyed it and blasted off the side cover. In blasting off the cover it destroyed all the cover mounting places which means the left side engine case is destroyed. I don't have pix today, but I will sunday.

In my mind its a manufacturer defect, unless someone thinks otherwise. The bike is a 2007 so its probably not under warranty, but what do you guys think I should do? What I'm gong to do is;

- Call KTM USA and see what they can help me with

- Find a used engine casing somewhere (I need help with this)

- Buy the rest of the parts new so this might not happen again

Let me know if any of you have any thoughts on this, that would be great!

thanks

tye

More proof of why all of us in roadracing called you a flaming idiot.

you want KTM to fix a bike with...200 hours on it?! good lord, learn to upkeep your bike, and you don't have issues like this. when was the bottom end ever rebuilt?

Crank probably not, its a one-off custom KTM racing crank. We will measure it and determine if its damaged, but I highly doubt it.

All the bearings will be replaced for sure.

no it isn't. KTM wasn't racing that bike in 2007 to produce a "custom KTM racing" crank. All American KTM had nothing to do with the 125sx, H and M also never touched that bike.

Now, if you have one of the very few companies whom build an aftermarket crank for the 125, then yes, you need to get it checked. Any catastrophic failure like an engine seize (*not "crease" like you spelled it) will cause the motor to get hurt easily.

This isn't your junkyard built 848, or your completely stock 749 you messed with, this is a true race-bred motor from the factory. They take a lot of maintenance.

tye

you are a total douche just like on wera forums too

I figured I'd update this thread.

We measured everything out and nothing took damage besides the stator unit.

We don't know why the stator unit failed, looks like the inside piece on the flywheel which contains the magnets delaminated and allowed everything to rub. Once it started to rub, things got hot (we saw evidence of major heating) and the heat plus the high RPM stresses of riding the bike hard, allowed a few of the rivets to pop and blamo, failure.

Anyhow, the motor is back together again and I rode it for the first time today, it felt a bit stronger then before, so it was probably needing a top end, even though the piston looked new.

Just to fill in a bit with my comment on the crank. The owner who sold me the bike told me it was a KTM factory crank. He was obviously full of shit, as pointed out above. The crank was a highly modified stock crank, with lots of C&C milling to reduce the weight. Obviously whoever did the work, knew what he was doing as it was very good work and clean.

Anyhow, the company I work with has good connections with KTM North America and I'm going to use everything in the book to contact them and just explain to them my situation and send them the part which failed. It was not a maintenance part, or something that you'd normally replace. In fact, we had the flywheel/generator unit out (to clean it) when we did the top end 50h ago and didn't see any problems. I also contacted many KTM service tech's during my hunt for parts and nobody had ever seen that issue before.

For what its worth, the bike is in tip-top shape once again.

Thanks to those who gave me good feedback, I did use it all!

You should put those pics up. . . . .

Exterior of flywheel

flywheelext.jpg

Interior of flywheel (notice its just magnet's, all of the metal which you normally see that keeps the magnets in there, is not pictured.

insideflywheel.jpg

Notice the mounting places for the screws to hold on the side cover, they are all broken off. Notice the crank is straight and there is no visible crack on the case.

engineside.jpg

thats a new one for sure

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