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View Full Version : Gearboxes, oil and valves (oh, my!)


bones33
05-16-2011, 04:52 PM
The gearbox should break in over time and become easier to use. My Sierra 200 was really sticky to get into neutral. I changed the oil at 20 miles and about 50, 80, 120, and 500. Lots of particles in the oil the first few changes. I understand these are the most critical changes in the engines entire life. By 500 miles the gearbox was about normal, by 1200 miles neutral was easy as pie, like a little engine should be.

If the dipstick poses any threat of coming off or interfering with the engine during operation, remove it. Using the sight glass prevents dirt from possibly entering the engine leading to a longer engine life possibiltiy. Oil level should be checked while the bike is upright on it's tires, NOT leaning on it's sidestand. Checking the sight glass on the sidestand will lead to overfilling, common on these bikes. When overfilled, the crankcase breather can send liquid oil into the intake causing piston, ring and or rod damage due to hydraulic pressure (oil does not compress like air/fuel mixture does).

Valve clearances should be about the same as the Sierra 200. The engines are very similar and of the same family. Loose is better than tight so at least it doesn't sound like you'll be burning your valves due to being too tight. After 10 miles of freeway riding the valves on my 200 begin to get a little noisy, just a little, not bad. A few miles of slower speeds and it is quiet again. Maybe something to do with the head expanding a little at higher temps increasing clearance a tad.

Congratulations on saving another chinabike! I'm sure happy with mine.