I just took apart my Husqvarna CR 125 top end and noticed that there's a letter "D" stamped on the bottom of the cylinder. If I've understood correctly the letter "D" indicates the size of the cylinder and at the same time the size of the piston I should be running, so if I get a new piston right now I should be buying a D size, correct? If this is the case, what is the point of making different size cylinders (A, B, C...) if the base volume is still the same (124cc)?
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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 The previous version was outdated and no longer supported.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 What does the "D" stamp in the bottom of my cylinder indicate?
- Thread starter Aksus
- Start date
The letters go up in increments of a one hundredth of a millimeter, or slightly less than half a thousandth. When mass production produces slight variances in the cylinder diameter, piston skirt sizes can also vary to match the specifications for clearance. The best way to determine what piston goes to what cylinder is still going to be using a dial bore gauge, t-gauge and micrometer to measure the piston at the lowest measureable point on the skirt, and the cylinder at the top. You can also use a a feeler gauge to get close enough, by slipping the piston into the cylinder, and seeing where it gets snug. The bottom of the cylinder will always wear the most, front to back. Piston skirts are wider at the bottom of the skirt than they are at the top. The top is small, to allow for heat expansion.