125-200cc I Think we TOASTED one...

It is the '09 hybrid WR125. After two days of riding at the Yamaha GNCC University School at Snowshoe before the Snowshoe GNCC the bike still seemed to be running good...Plug looked good for the small adjustemnt made for the additional 4,000 feet of elevation. It was the old parking lot garage thing, new back tire, change the oil, change the air filter, replace the broken FMF silencer with the stocker, new brake pedal springs - thanks to Fred and FAR Husky, and replace another broken head stay brace, all in all not to bad.

Race on Sunday, 10AM, Andy came thru in 1st with a 2 minute lead and had the hammer down when he left the pits only to have the motor quit about 2 miles from the finish...and I mean quit. He had to sit and watch 2nd thru 6th go by, although a couple of them actually slowed/stopped to make sure he was ok. Two of them found me to let me know he was ok, just bike problems. Any parent can appreciate that!
He said it was making some strange noises and than just bogged out and quit.

The brutal track part...lots of push and pull hills, deep wood ruts, lots of clutch and lots of steaming bikes, including his. I haven't had the chance to pull it apart yet; still has some compression, plug looks gray(not good), I will find out how much radiator fluid is left, if any... I think it overheated and did who knows what...

I will keep you posted, need some help with a quick fix; AMA National this coming weekend in New York and the Ohio GNCC/AMA National the week after that...going to need something to race!

Currently Andy sits first in points at the GNCC and tied for second in the AMA Nationals...

Looking for the Cafe brainstorm...will keep you updated, teardown tonight...

As I'm going in I'll try to analyze all...

Thanks.

Gray plug often means aluminum. Wouldn't be surprised if the top of the piston looks like hell.

I have a great 125 top end minus the head with a good used piston, PM if interested

grey plug = bad
we were recently winning a race and the same happened, pulled plug and it was grey, thats how i know grey = bad. ours actually made a loud POP when it decided to quit and our electrode was missing. LOL
i feel your pain....

...88 I'l let you know, Thanks

I have a complete new Powersealed 144 topend and piston...I just hope the crank is good. Usually pull the engine, turn upside down and flush the crank area and see what comes out, usually sacrifice a white towel under the engine to see what's there. (short on time...might just turn the whole bike upside down!)

I'm still curious why? If it's not from overheating...it could be scary as to why...

Thanks for the input.

OK...maybe not as bad as I was gue$$ing...

No fluid in the radiators, I'll have them checked, must have poked a hole, really nothing visible but it does not take much to pump out what little is in there if it's a low hole.

The pictures kind of tell the story...a lot of heat up front at the exhaust port. I'm really surprised it quit running when it did. Usually they keep running til total meltdown. Not sure why it quit early, but I'm happy it did and will keep researching.

Piston had the ring locked in the front with even wear on the center line...no marks on top made by flying debris, not alot of meat gone from the piston.



Cylinder has scuff marks on exhaust side, a little too rough right above the ports and on the center bridge.

Maybe a light hone?



Plug really not a gray as I first let on...really not too bad. The black inner o-ring was brittle, definitly cooked!



Again, not really sure why it shut off when it did. But I have options! Which is a good thing. Going to go finish cleaning things up, pull the radiators and figure out where I go next...125 or 144 for the weekend?

2 cents???

Little Mr. Piston got really hot and went squeak, that's why it stopped when it did! Mr. Piston can't go up and down when it is bigger than the bore. I say go 144! My WR144 was just great this weekend, on super slick trails working my club's Hare Scrambles.

hmm could of sworn my piston only has 2 holes, yours has 4

Bummer. What's with all the 125 failures lately!?!?
Please let us know when you find the culprit so others can take precautionary measures to avoid the same fate.

That's not to bad for a heat seizure. You need to get the aluminum off the cylinder wall before you hone it. New piston and rings and you are probably ready to go. Install new gaskets and o-rings. You might just use your linkage, cups, spacers, and power valve shaft in the 144 top end and try it.

More people from this forum riding them? More folks on the machines = more ride reports and most likely more reports if something is wrong. Seems like there have been a lot of folks going to them due to incentives, ease of handling in woods and overall lower maintenance costs. Hell, I've even thought about it but the thought of messing with a fuel/oil mix that I can't use in any of my other 6 bikes stops me so far. I've never owned a 2-stroker yet but can appreciate their advantages for sure.

I normally would agree with your post, but the last few failures I've heard about have all been heat related. If it was due to lost coolant then I'm curious as to how this happened so I can take precautions to avoid making one of these blow motor posts of my own!

Hmmm that looks a lot like mine, but mine was seized on the front and back. It happened shortly after a 70mph pull on a gravel road in an ISDE... Locked up solid. I am still not sure exactly what happened. I put on motgob1's stock 125 piston and cylinder and it has been running fine.

This is the jetting I was running at the time...
Mikuni TMXX
RM needle in the 3rd position
40 pilot
450 main
1.5 turns out on the air screw.
Elevation was 4500 feet
engine operating temperature was 115 degrees at the time of seizure
Fuel was 92 octane pump gas
Oil was Castrol TTS at 32:1

Here is a video of how it was running 5 minutes before it locked up...

Photo's...















Later,

In my case I would say, don't hold it wide open for an extended period without hitting the kill switch. Or the 460 main we are running with the RM needle at sea level is too lean for long WOT pulls. Or a 450 main at 4500ft...

Later,

pahusky, not that it helps much but that looks just like what happend to the piston out of the 94 rm250 we just rebuilt...

I was told by a fast Husky 125 rider, that usually it's too small a pilot that gets you. Your main is fine for WOT run, but when you snap the throttle shut at that speed the too small a pilot starves the bike of premix for lube and she squeaks.

All good stuff...The jetting I'm confident did not cause this one. We have been running the same for the last couple of races and traveling to 4000' from 400' and dropping the needle one clip did not cause this. Being that he hammered this thing for two days before the race at the same elevation with no problems(actually still rich but running good). It was one of those races, lots of deep woods new track, really tacky mud with deep ruts, roots and rocks, lots of revs and clutching, banging your way thru. If anybody was there, you'd know.

Main 470, Pilot 35, RM Needle 2 down, #5 slide, Klotz R50 40:1, Hi-test pump gas (the jetting may have actually helped save me worse problems)

I believe when I'm done the cause will be a hole in one of the rads, extreme temps/pressure pumping out the fluid. Hi-temp seizure.

Othes have suggested that if this happens on a more extreme basis; replace main seals as a precaution.

Smoke, the stocker has 2 holes at the exhaust side, the Wiseco has four if you use the the cr piston, #760M05400 (on Wiseco's site under '06 CR125) or you could drill two more, keeps the bridge cooler.

metteer, what kind of shape were the crank bearings in after that episode?

PC - Rads were empty...Keep an eye on the coolant level after each ride - they will level out a little lower than the top because of expansion. but sooner or later should stay at a consistant level. If you're adding all the time, leaking inside or out.

By the way; remember, 16 year old pilot who's learning how to keep it pinned and make it go by letting the clutch out...he does not baby
this piece of equipment and I don't want him to either...He was was flat out hauling ass on this thing on a way to first in class when it went.

We'll be ready next time, heading to New York this weekend to take care of some AMA National business!

After the rad repair or replacement, and confirmation that the 125 is OK...I have options...125/144

Thanks to all for the offers of spare pieces/parts to keep him running...I think I'll be OK this time, but in the future - Who Knows...

Our goal is to finish the 2011 season with 2 national titles on the Husky...

Kart racers used to use the choke/bypass circuit to richen things up a bunch during WOT runs on long straights and when they back off the throttle. Not sure if that's how they still do it, but food for thought............

(plug looks lean to me!) put the needle back, go up one main for snotty or faster course, down one per 3000' dif going up the mtn. once ya have a baseline ya really only need to mess with the main and AS. messing with needles is baaaad. always read plug after adjustment etc...

check coolant overflow hose for blockage and blow-out into skid-pan when o/hting. if no coolant blew out under bike then ya gotta leak somewhere. check for warpage everywhere. careful torqueing head stays and bolts.

maybe gently press test crankcase w/ soapy solution when its back together if ya have time...1 psi or so.

dood- super sorry bout the squeak. grats to you and the young gun on ripping it to them!

mreeep!

pv...the plug in the pic is heat treated, not a good indication of jetting.

In the pic below are the plugs I pulled each day to make sure we were ok at the elevation...like I said certainly rich/safe, but running good. Again, I don't think jetting was the cause...

I pulled the plug each day after the school was over. The videos show the type of riding they finished up with each day... playing on the hill after the school was over. During the school they were all over the mountain...

The bottom one is Thad Duvall doing a whip on the play hill...just for kicks...the hill is certainly steeper than it looks!