• 4 Stroke Husqvarna Motorcycles Made In Italy - About 1989 to 2014
    TE = 4st Enduro & TC = 4st Cross

  • Hi everyone,

    As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.

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Questions for those who have done ring jobs

OlderHuskyRider

Husqvarna
Pro Class
2010 TE450, 10k miles: I have some blow-by, strong steady stream of air from the crankcase vent to the airbox, also, some puffs of blue smoke on acceleration, oil collecting in the bottom of air filter element.

What are the risks if I keep running for a while like this, the bike is fast, the spark plug stays dry and doesn't foul, I only burn up about 3-4 oz between 1000 mile oil changes. Am I risking any ring breakage or any other bad things if I run until the plug starts fouling from too much oil entering the combustion chamber?

Are these bikes like 2 strokes, put on new rings, gap them, hone the cylinder and go?

Any other tips, info on different reasons for blow-by, from those who have done these jobs would be welcome.
 
I cannot advise on your particular bike but I owned a Husaberg 650 a few years back which burned about 150ml of oil every 4-5 hours of use, occasional puff of blue smoke but compression was always good and performance was good too. I ran it like that for a few years and decided to replace the rings to try and stop the oil consumption, new rings, liner honed and back together it went, guess what, still burnt oil, still the occasional puff of smoke, still went like a rocket.
 
I cannot advise on your particular bike but I owned a Husaberg 650 a few years back which burned about 150ml of oil every 4-5 hours of use, occasional puff of blue smoke but compression was always good and performance was good too. I ran it like that for a few years and decided to replace the rings to try and stop the oil consumption, new rings, liner honed and back together it went, guess what, still burnt oil, still the occasional puff of smoke, still went like a rocket.

Thanks for your input, my blow-by was leaking out the plastic "L" at the head and spraying oil all over my spark plug cap and cylinder. I hope I have that sealed up now and all of it will go back to the airbox, where I have put a piece of foam in the bottom of the airbox to soak up the oil when it drips off the bottom of the air filter element. I am leaning towards running this bike as is, until is gets worse, due largely to what you experienced and what I have experienced before on other bikes: try to solve a problem, lotsa time and expense and the problem is not solved.
 
OHR how ya doing Bud
A heads up you cant hone the cylinder it has a nickasel coating
you have to send it in to be re-plated along with the new piston piston for sizing
might be time for a rebuild also ya might want to check your valve seals
 
OHR how ya doing Bud
A heads up you cant hone the cylinder it has a nickasel coating
you have to send it in to be re-plated along with the new piston piston for sizing
might be time for a rebuild also ya might want to check your valve seals

I am hoping that my cylinder is undamaged and I would just hone it to de-glaze it, with a hone or a piece of green scrub pad, that's what I have been reading. I guess I'll measure the clearances for the piston and cylinder when I get it torn down this winter and hope that I don't need a piston or cylinder work done.
 
Nickasil bores can be and are honed.
wow you learn something new every day
what we do is send the old cylinder in to be re-plated and they measure the new piston that is
sent in with the jug then hone the re-plated cylinder to the correct specks piston to wall clearance
and it is like new I guess a Little over the top but thats how we like it
 
Just a couple of thoughts:
If it were me, I wouldn't allow the breather hose to discharge on the filter. The hot oil mist will wash the filter oil off and most if it will run off.
Honing and glaze breaking are two different things.
Honing is done with a precision machine like a Sunnen for final sizeing after boring and the honing of plated cylinders is done with diamond stones.
Glaze breaking is done with the inexpensive hand held aluminum oxide ball or three stone type tools that you see at the auto parts store and only does what it's name implies.

A sometimes overlooked cause of oil usage is worn ring grooves. A loose ring groove can cause the ring to wobble and let oil by on the inside and outside. The piston/cylinder clearance can be in spec and the engine can still burn oil if the ring grooves are loose.
 
Just a couple of thoughts:
If it were me, I wouldn't allow the breather hose to discharge on the filter. The hot oil mist will wash the filter oil off and most if it will run off.
Honing and glaze breaking are two different things.
Honing is done with a precision machine like a Sunnen for final sizeing after boring and the honing of plated cylinders is done with diamond stones.
Glaze breaking is done with the inexpensive hand held aluminum oxide ball or three stone type tools that you see at the auto parts store and only does what it's name implies.

A sometimes overlooked cause of oil usage is worn ring grooves. A loose ring groove can cause the ring to wobble and let oil by on the inside and outside. The piston/cylinder clearance can be in spec and the engine can still burn oil if the ring grooves are loose.

The breather disharges on the inside of the rubber boot in between the air filter frame and the throttle body. The oil is condensing on the boot and then dripping/running back to the very bottom of the air filter element. I don't think there is any danger of my filter oil being removed by this action.

Thanks for the honing deglazing info. I'll be deglazing with a 3 stone tool, less than 60 seconds in the jug.

The worn ring grooves info is very interesting, maybe that's why Freaky's Husaberg still burnt oil after a ring job, he had worn ring grooves. I guess a new piston would solve that, I think I am even more leaning to running the bike as is, and planning on a piston and rings replacement when I do tear it down, maybe cam chain as well.
 
I always wash my cylinders and mic them for wear. I always get a second opinion from a fellow machinist. Usually its just light run with a drill and a glaze breaker before I add new rings and parts. When you do get ready to assemble, use a chlorinated hydrocarbon in your assembly lube. This will adhere to the cylinder walls and prevent oxidizing break in oil from glazing your cylinder walls. Your rings will seat slowly and evenly this way and your engines will last much longer.
 
Interesting info in this thread. Never knew you could hone nikasil and never thought about worn ring grooves. As my watchmaking instructor used to say: "You learn something new every day... If you start out dumb enough"... Well I guess I had a good, dumb start today!
 
Maybe I'm missing something here but why after 10,000 miles and experiencing signs of wear would you risk not fitting a complete Piston Kit ?

I would want it done ASAP to avoid failure.

If you are stripping down the Motor the extra cost of a Piston is money well spent.

Dont want to offend anyone but if that Piston fails, it will cost you a hell of a lot more !!!
 
Maybe I'm missing something here but why after 10,000 miles and experiencing signs of wear would you risk not fitting a complete Piston Kit ?
I would want it done ASAP to avoid failure.
If you are stripping down the Motor the extra cost of a Piston is money well spent.
Dont want to offend anyone but if that Piston fails, it will cost you a hell of a lot more !!!

If I order a standard size OEM piston, will it fit my bore the way it should or is it possible that the piston will be smaller or larger and require me to get a build-up or grind-down job done on a Nikasil cylinder?
 
The best way to tell is when you check the cylinder(as in measuring the bore) then you would have the dimensions of the cylinder, to compare to the piston dimensions. If the bore is within tolerance I would think that the standard piston and rings would be what you want and using the "ball hone" for deglazing would be all that you would have to do to the cylinder. I have to agree with some of the others that after 10000 miles if I was going into the engine at that point I would be replacing anything questionable after that amount of time on the motor to avoid having to open it back up for a possible catastrophic and expensive failure.
 
I will definitely put a mic on the ring grooves, piston and cylinder. If the tolerances are too large, I'll replace the piston and rings together. If the ring grooves on the piston are within tolerances, and the cylinder/piston clearances are within tolerances, I don't see a need to replace a good piston with one that may have a defect.
 
I will definitely put a mic on the ring grooves, piston and cylinder. If the tolerances are too large, I'll replace the piston and rings together. If the ring grooves on the piston are within tolerances, and the cylinder/piston clearances are within tolerances, I don't see a need to replace a good piston with one that may have a defect.

I'm confused ! So you would prefer a Piston thats done 10,000 miles to a new one ?

What about the possibility of cracks etc... ?
 
I'm confused ! So you would prefer a Piston thats done 10,000 miles to a new one ?

Actually, yes. Unless the piston clearances are out of spec, I would trust mine more than a new one, plus, what is the new one is not sized for my cylinder, don't I have to get my Mikasil cylinder bored or built up to match the new piston? So $315 parts and another $200 work on the cylinder?!?!? Like I said, if clearances are good, I'll stick with the original.
 
Actually, yes. Unless the piston clearances are out of spec, I would trust mine more than a new one, plus, what is the new one is not sized for my cylinder, don't I have to get my Mikasil cylinder bored or built up to match the new piston? So $315 parts and another $200 work on the cylinder?!?!? Like I said, if clearances are good, I'll stick with the original.

Your bike, Your choice, Your problem !

If the bike is standard bore (I assume) a standard piston should fit . That is part of the reason for Nikasil bores . Pistons can break up and fail thats a big reason to change but as above !

But why you trust yours more than a new one I dont get ! Yours was new once !!!

I have boxes of "used but trusted" parts , I'm willing to sell to you at a good price !!!
 
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