Dear Mr. Know-It-All,
I am doing a top end on my 2006 KTM 300 XC-W and have some concern. While the Nikasil appears to be in good shape, there is an awkward line at the top of my cylinder. Is this where the rings are stopping? What made it?
“KTM Mike”
via [email protected]

This, my friend, is where your rings are stopping at the top of the cylinder. The ridge is visible because it is a buildup of material that has been lost over the years. The top portion above the line you see is actually the dimension your cylinder was when it was brand new. Several hundreds of hours of your piston hammering up and down sloughs off minor amounts of your cylinder plating and deposits it right above the ring line. You can get technical and measure the bore and go with the next-size piston, if it is still within specs. But, my rule of thumb is that if your fingernail can catch this ridge, it is time for a re-plate job.

Dear Mr. Know-It-All,
It may be a surprise to recreation-obsessed suburbanites that dirt bikes are actually used for work way out here in cattle country. Dirt bikes—being extremely agile, narrow and fast—are ideal for checking fences, herding cows and driving off wolves or moose. My question goes to the old two-stroke versus four-stroke debate, as I have a 2005 CR250 two-stroke (built to DB spec) and a 2019 KX450. Cows hardly budge if I scream by on the CR, but nearly stampede when I putt by on the KX. Conversely, geese, grouse and chickens hardly move for the KX, but flock off like DB editors to an ice cream truck when the CR goes by. Can you explain this phenomenon? Which bike beyond the two stated would DB staff gravitate to if ever they were to become farmers or ranchers?
In the shadow of the Rockies
P.S. A shootout between the Suzuki 200 Trojan and the Yamaha AG200F agricultural models is way overdue.

M, I opted to remove my immediate inclination to soundly scold your impertinence for tagging us ‘recreation obsessed suburbanites’.  Until I mulled it over sipping a cognac and caressing a nice Cohiba cigar.  As to which machine we’d select for herding ranch work- the CR no doubt. More nimble and easier on the knees when starting.

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