• 2 Stroke Husqvarna Motorcycles Made In Italy - About 1989 to 2014
     WR = 2st Enduro & CR = 2st 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.

    When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.

    Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.

    Unfortunately, the new software version doesn’t support importing the old site’s styles, so for now, you’ll see the XenForo default style. This may change over time.

    Coffee didn’t document the work he did on the site, so I’ve been digging through the old setup to understand how everything was running. There may still be things I’ve missed. One known issue is that email functionality is not yet working on the new site, but I hope to resolve this over time.

    Thanks for your patience and support!

125-200cc 125 Piston Dome - Detonation or Normal?

J

JRod4928

Husqvarna
AA Class
Decided this weekend to install the 144, and I'm glad I did. The old 125 appeared to have been cold seized at some point. I'm not sure if I was responsible but the previous owner put on 30 hours running 100:1, and based on the rear tire that was on the bike, he rode a lot of roads, burnt out a lot, and didn't take extremely good care of it. I ran it about 3 hours at 32:1 trail riding. I'm not saying he's responsible for the cold seize, but you can do the math. The bike started and ran fine, in my other "first impressions" thread I mentioned that the jetting seemed off, but that may be a wrong assessment now that I know it was cold seized.

Anyway, it looks like a cold seize (exhaust and rt side transfer port) but the piston dome looks burnt as well. Does this look like detonation to you, as well as a cold seize? Is this a jetting issue that I should be concerned about with the 144, or is it simply a cold seize due to not warming up?
 

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100:1? was he running interceptor?

Based on that my guess would be loss of lubrication, especially if that's the only spot with wear.

Did he tell you he seized it?
 
I don't care what oil you run, if you think 100:1 is sufficient, you are BEGGING for problems. The 32:1 you chose to run it at is what you need for extended high-RPM operation, 40 to 50:1 is sufficient for average woods use and trailriding, and I'd never go below 50:1 for any operation, anytime, any RPM, any conditions.

I'm not seeing detonation damage in the provided pictures. Cold seizure is usually a "4 corner" seizure. That looks like a lubrication seizure, possibly with a bit of cold-seize element to it. Not to upset or alarm you, but I'd be fearing for the lifespan of my crankshaft's Big-end bearing.....
 
I had the same thought, but there is no evidence of any issues in the bottom end as if now. I'm making myself feel better by thinking that it has very low hours, he didn't race it (hence he probably didn't ride that hard, except for very short periods of time) and that the oil IS rated for 100:1. A lot of people run it.... Would I? He'll no. But it has been done and some people have no issues

At least that's what I'm telling myself *crosses fingers*
 
I have never blown a top end in my life, so Im not terribly experienced when it comes to identifying reasons why a piston looks the way it does.
 
I've seen something like that happen to a piston when the piston pin circlip comes loose while the engine is running, which happens when somebody either uses the wrong circlip or doesn't get the circlip seated in the groove properly. You didn't show a picture of any damage to that side of the cylinder though.
 
Never
Dirtdame said:
I've seen something like that happen to a piston when the piston pin circlip comes loose while the engine is running, which happens when somebody either uses the wrong circlip or doesn't get the circlip seated in the groove properly. You didn't show a picture of any damage to that side of the cylinder though.
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Never thought about that before. The circlips were seated properly though. I know because when I removed them, they flew out of the seat and hit my forehead.... BOTH of them. Lol
 
JRod4928 said:
Never


Never thought about that before. The circlips were seated properly though. I know because when I removed them, they flew out of the seat and hit my forehead.... BOTH of them. Lol
Click to expand...


That's why you use eye protection when working with tools right ? :lol:



With oil ratio the guy was running, I agree with MotoMarc. I'm not a wide open guy in the woods but when I'm in the sand it's wide open. I'm running 40:1 and hopefully it will extend the top end life for me.
 
i know its just another story, but i have always run 40:1...always had longevity and good performance..i dont race hard, maybe i would go 32:1 for that...
 
Agree with the above. It might be Ok to run 100:1 but 32-40:1 is way better and more than twice the lube.
 
100-1 would be fine in the appropriate application. I run my chainsaw at 75-1, but I wouldn't do that with my bike.
 
MotoMarc36 said:
I don't care what oil you run, if you think 100:1 is sufficient, you are BEGGING for problems. The 32:1 you chose to run it at is what you need for extended high-RPM operation, 40 to 50:1 is sufficient for average woods use and trailriding, and I'd never go below 50:1 for any operation, anytime, any RPM, any conditions.

I'm not seeing detonation damage in the provided pictures. Cold seizure is usually a "4 corner" seizure. That looks like a lubrication seizure, possibly with a bit of cold-seize element to it. Not to upset or alarm you, but I'd be fearing for the lifespan of my crankshaft's Big-end bearing.....
Click to expand...

I agree......it all depends on the load on the motor. I bet you could try to hone off that aluminum from the cylinder, slap in a new piston and probably run it for 2 more years!

The alternative is to split the cases and replace the rod and crank bearings...is there any play or roughness there?
 
R_Little said:
I agree......it all depends on the load on the motor. I bet you could try to hone off that aluminum from the cylinder, slap in a new piston and probably run it for 2 more years!

The alternative is to split the cases and replace the rod and crank bearings...is there any play or roughness there?
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There is zero movement at the flywheel or the connecting rod - i checked when I had the jug off. There is the normal side to side play, but nothing out of the ordinary. No roughness either, and visually, the crank didn't look toasted or scuffed in any way - I think it's fine. Honing the cylinder is definitely a possibility - I'm sure after honing it, it'd be fine.

My plan is to turn it into a 165, or trade it + my WER steering damper for a 165 anyway. :thumbsup: Either way - it's all still perfectly usable.
 
Did you ride it yet? How does it compare?

You can also use muriatic acid to remove the aluminum from the cylinder. It'll eat the aluminum but not the plating. Dab it on with a q-tip and wipe it after a few minutes and repeat until it doesn't smoke when applied. Wear eye protection and be very careful, it's pretty nasty stuff.
 
uranys said:
Did you ride it yet? How does it compare?

You can also use muriatic acid to remove the aluminum from the cylinder. It'll eat the aluminum but not the plating. Dab it on with a q-tip and wipe it after a few minutes and repeat until it doesn't smoke when applied. Wear eye protection and be very careful, it's pretty nasty stuff.
Click to expand...

Never heard of that, i'll have to give it a shot when I get a chance.

I did ride it, but only for about 5 minutes - I won't get on it hard until I break it in. It sounded deeper (read: awesomer) though!
 
By the way - should there be an o-ring beneath the PV seat? I'm pointing to it here with a pick. My power valve chamber was 1/2 full of liquid exhaust residue. I wasn't running it too hard before I quit the last time I was out riding it, so I guess I could see why it filled up, but holy crap man. lol
 

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