• 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 The previous version was outdated and no longer supported.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!

250-500cc Another Piston Thread

Now I'm hesitant for the Wiseco or vertex.

Should I pull the cylinder off and check the letter first then order a stock piston to match the cylinder letter?
 
I wouldn't be afraid of the Weisco in a 250 as long as the clearance was on the big side of the spec. If I had a 300 I think I'd go with a factory piston only because I've heard of more people having problems with the 300. I went back with the factory piston on my 250 because I had over 300 hours on it and I could have just put rings on it and done another 100 hours.

Since I wasn't there to measure the clearance before their engines were put together I don't think it's fair to blame the piston, the 4 corner seizure failure was most likely too tight of clearance and maybe scuffing from revving the engine before it's fully warmed up.
 
I'll let ya know once I can get the jug back on. I've been screwing around with different ways to compress the rings. Don't have the proper round clamp type, don't wanna scratch my pretty piston with a hose clamp, so I'm down to a fat zip ty.
 
Huskynoobee said:
I'll let ya know once I can get the jug back on. I've been screwing around with different ways to compress the rings. Don't have the proper round clamp type, don't wanna scratch my pretty piston with a hose clamp, so I'm down to a fat zip ty.
Click to expand...
You should be able to use your fingers to squeeze the rings as you feed the piston into the taper at the bottom of the cylinder
 
I ain't that talented:doh:. I have bent rings before and honestly am a little intimidated by that experience so I get nervous as soon as I start slipping it in there. The piston into the cylinder I mean of course...
 
The motor is together. Fat zip ty worked great with my nervous hands. I can mess with high voltage and am steady, but give me a little engine to play with and I'm all thumbs. Should have it all together and ready to run this evening.
 
Sweet best of luck, the first kick over is always nerve racking.
Must of reassembled scores of engines an i always get the is everything right? feeling its ace :)

Love it when it first fires, yet to have one not work on me.
 
It's a runner folks! First 2 heat cycles are complete and she runs fine. Started first kick on the second cycle. I swear it seems that I hear less piston slap, but to be honest I'm just glad to get it back together. I'm going to take it to a local place to do the putt around sessions to finish the run in tomorrow. I'll report back after the riding tests.
 
Did it seem to have any more compression when you kicked it? Hoping it cures the clunking sound when lugging. Good luck with the test run, I"m tearing mine down Tuesday. New Vertex piston is waiting on the workbench. Also putting in new reeds and wrist pin bearing.
 
Yes it is a little stiffer. The piston slap is gone, but it will still slightly protest to being lugged to low. I'm waiting for it to cool down so I can take it on a longer ride. It is much snappier than before and I am really just getting the rings settled.

I've done the manual recommend 2 heat cycles no load, then 10 min easy ride followed by the 15 minute ride I just finished. I rode a couple of easy flowing trails I usually ride to warm up mostly 2nd and 3rd gear stuff with lots of throttle variation.

Now i just need to bleed the rear brake. It seems to have developed a bubble since the last time I rode it in November. It's two pumps and an apology right now. The fun never ends...
 
Questions... Your noise when lugging or just off idle.
Is your gas FRESH?? Ethanol will absorb moisture right out of the air.
How is your jetting? Maybe you might want to drop the clip on the needle to raise it out of the jet for more gas to pass throught, or go up a size on the primary.

Your old piston... If you look at the inside of it, does it look burnt black? If so it would be a sign that there is not enough gas entering the bottom end to cool it properly
 
OK, I'm game in case this helps others!

1. Lugging, but no piston slap, more like chain noise now. On the last ride I paid special attention and it was certainly not an off idle thing, I even made sure I did some slow technical climbs one gear high to get it to bog.
2. 50/50 100LL Av gas and 110 leaded Sunoco, no ethanol crap allowed in my race bike
3. The jetting is crisp, but not lean, plug is light brown, I'm not in a hurry to mess with a good thing.
4. Old piston is clean with slight brown color inside. There were zero signs of detonation and just a little carbon on top that was chocolate on the edge.

At this point I can say that if you're wondering if a forged piston is good, it works good for me so far. I get another day of riding before the National next weekend and I'm sure it will continue to improve with each run. Realizing I'm running this piston I'm being very careful to make sure I let the engine get good and warm before putting a load on it.

It is certainly a big improvement over the old piston and rings that were at the end of wear limits. I'm going to go out on a limb and say I feel at least a 10% overall power increase. I did a short burst where I really got it on the pipe toward the end of a 40 plus minute last ride today and the smile was plastered on my face.
 
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