• Husqvarna Motorcycles Made In Sweden - About 1988 and older

  • 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 The previous version was outdated and no longer supported.

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    Thanks for your patience and support!

Do KX500 rings fit CR430 (82) ???

The 430 piston is 86mm, what is the diameter of the KX500 piston? If identical it would depend on the minor diameter of the ring groove and the groove width
 
The KX500 std bore is 86mm. The KX ring measures 1.2mm by 3.2mm. The standard bore Mahle ring is 1.4mm by 3.4mm. I placed feeler gauge in ring groove and measured 1.4mm tight. 1.2mm gives slight clearance (just a hint of movement) . Anyone know what side clearance should be on rings for Mahle piston? (I suspect less than .1MM ~ 4 thou).... anyway, I ordered a KX500 ring today ($14.00, compared to $90 for a husky ring). I probably won't run it with this ring... just a "what if".... I am just amusing myself....If nothing more it is an excercise in sourcing spares... because lets face it, parts are getting really scarce for these bikes... and if we think we cannot substitute japanese parts, we are kidding ourselves. I only wish some of these maufacturers had a vintage spares program like Jaguar. M
 
What about aftermarket KX500 piston rings. There are a lot of aftermarket piston makers and their rings may be just slightly different enough to work. Cam.
 
A piston ring must be the perfect thickness for the piston. No exceptions. 0.2m/m smaller than it should be is a recipie for disaster. I think the Mahle pistons have a 1.5m/m thick ring - but I may be wrong. Don't forget the other crucial dimension is the end gap when the ring is in the bore. There needs to be sufficient end gap to allow the ends of the ring not to touch each other when everything is hot, and not so much that 'blow-by' occours.

Measure the end gap by placing the ring near the top of the bore. Push it 'square' by using the piston from below. Also, to see how worn the bore is, now push the ring down to where the ports are in the bore and check the gap again....

Andy
 
If all else fails, buy a Wossner piston and then you do not need to do the engineering and risk ruining a top end
 
Thomas, have you been using these rings for a while or did you just order them? I would be interested in knowing if this is a viable soloution to spending $100.00 USD for NOS rings.
 
I got my pistonring this spring. Been running it for more than 10 hours now.
I haven't opened the top yet, so I can't say anything about the condition of the ring so far. But the compression is still good.
I had the same thaught as You, why spend $100.00 USD on a piston ring when I can get it for less.
 
You do need to make sure the ring matches the original in every respect not just OD and thickness. The ID has to match as well. Otherwise you will see long term undetectable damage. Remember rings are made to fit pistons, not all pistons are the same. A better question would be ... Can a KX500 piston be used in a 430? That would involve checking the wrist pin to Dome dim,and the wrist pin diameter. Also any porting windows cut into piston?
 
jimspac said:
I would buy them and thoughly inspect them prior to using. For the price, it is viable if every dimension matches the Mahle ring perfectly. Up, Down, Inside, & Out
Click to expand...

Every manual I can find on the topic of reciprocating engines specifies the same tolerances for side clearance... Maximum .008" upon install this amounts to .2 MM, any more and you will risk ring breakage and or piston fracture... Having said that the minimum side clearance should be no less than .001" /.025MM so that the ring can move slightly and clear itself of wear particles. If the ring jams then it will heat up and anneal... which causes loss of compression... and scoring of the wall... The end gap should be .005" per inch of bore... this can be adjusted carefully with a dremel after first checking it in the bore and squaring it up with the piston. Check end gap with a feeler gauge at the mid way point (about 1.45" from top of the barrel, CR430) this is the 90 degree crankpin position and the piston velocity is highest... this is the theoretical highest wear point of the barrel wall.

The stock KX500 rings produce a .3 mm side clearance (I checked it) in a Mahle Piston, this is excessive and can produce only poor results. Any Cast iron ring of the same dimensions as the mahle ring should work as long as the clearances are within the ones specified above. Do not use chrome plated rings (wiseco) in a chrome bore. Not a concern with cast sleeve, as with the older huskys. If you are not sure if someone has chromed the barrel use a jewlers glass (magnifier) and look closely at the bore surface. If it has fine cracks like, spiderwebs (not hone marks) all over the surface then it was chromed.

If you are in doubt, pitch it..... in favor of the Wossner Kit.

Thanks for all of your input... an interesting string for sure.

Mike
 
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