What is the valve clearance of Zongshen CB250?
3 Answers
The valve clearance of Zongshen CB is between 0.03 and 0.07 mm, and it is generally better to adjust it to 0.05 mm. Effects of excessive clearance: It causes abnormal metal knocking sounds. Excessive valve clearance in the engine will cause abnormal metal knocking sounds and leave marks on the rocker arm, valve stem, etc. Do not adjust the clearance too small for the sake of sound, otherwise it will easily wear the rocker arm and camshaft, and may cause difficulties in starting and unstable idle speed. Effects of insufficient clearance: Insufficient valve clearance in the engine will cause the valve to not close tightly when the engine is hot, resulting in air leakage, reduced engine power, and even burning of the valve.
I've been riding motorcycles for many years. The valve clearance for the Zongshen CB250 is typically set at about 0.10mm for the intake valve and 0.15mm for the exhaust valve when cold. Why is clearance important? Because if it's too tight, the engine idle will be unstable, and the valves can easily burn out; if it's too loose, it will cause a tapping noise and affect performance. Inspection and adjustment are usually done every 10,000 kilometers or during maintenance, using a feeler gauge and professional tools. Remember to check your owner's manual, as there may be slight variations between different year models. If you've lost the manual, try contacting a Zongshen service center for detailed specifications. Maintaining the correct clearance not only improves smooth acceleration but also saves fuel and extends engine life—developing a habit of regular checks is key. Don't forget to clean the dust around the engine to prevent debris from causing wear and tear.
I think the general valve clearance range for the Zongshen CB250 is around 0.10mm for the intake and approximately 0.15mm for the exhaust. When adjusting, ensure the engine is completely cooled, and find a quiet place to carefully listen for any abnormal noises—abnormal clearance is usually accompanied by a ticking sound. For a simple DIY job, you'll need a feeler gauge and a wrench, but it's strongly recommended to entrust the task to a professional mechanic to avoid engine damage from incorrect operation. Remember to also check the oil filter and chain tension, as these maintenance steps are interrelated—handling them together is both efficient and cost-effective. The manual is an essential tool; if unsure, consult a nearby motorcycle repair shop or search online for user group tips.
