The CG250 Engine has grown in popularity in last several years as the engine of choice for larger Chinese ATVs, DirtBikes and more. The Chinese Dirt Bike, Chinese Motorcyle Factories favored this engine in their designs. The first experience we had with this engine was in a Hy-Bird Enduro style motorcycle.
EASILY IDENTIFIED due to being a PUSH-ROD style engine design. There is NO overhead camshaft and NO camshaft timing chain. **PUSH-RODS operate the overhead valves.**
We have seen this engine in AIR-COOLED and WATER COOLED versions. We stock parts for two different bore sizes also. There is a 63mm bore (200cc) and a 68mm bore size (250cc).
The water cooled version, we have only seen in a 200cc (63mm) bore size. The water cooler uses a different style of piston than the air cooled 200cc. Do not mix pistons up between these engines or you may have problems.
The cylinder heads are also different between the 200cc and 250cc air cooled style engine. Larger valves in the 250cc head and longer push-rods are used. Of course different head gaskets are used also due to bore size.
Electric starter problems are most common complaints received. Some use a 9 spline starter and others use a 11 spline starter. Both starter bolt up the same. A series of reduction starter gears are used and we have found different variation in sizes and number of teeth used in these starter gears. Also two different starter clutches, a multi-sprag starter clutch and 3 sprag starter clutch has been known to us. The starter clutches will not interchange. Only way to verify which starter clutch you have is by dis-assembly and removal of the flywheel.
This CG engine is always a manual clutch style with the handlebar mounted clutch lever on left side of handlebars. There is also models with reverse gear for the ATV installations and the reverse operating feature is ALWAYS located on the same foot shifter with the forward gears. ATVs usually have 4 forward gears and 1 reverse gear. Motorcycles are normally equipped with 5 forward gears.
Transmission problems seem to be rare, (we stock some transmission gears and shafts), but we sell more clutch packs than anything else. This engine uses HONDA style clutch discs and we stock/ship a high performance clutch fiber disc kit by CLUTCH FACTORY.
The carburetor used on these engines is either the PZ27 or PZ30 Mikuni style carbs.
We do not know what the engine is cloned from or if it is a TRUE CHINESE ENGINE design??? NOT A CLONE??
Let us know if you are aware of any pushrod style engines from the past.
We believe this engine to be a fairly durable engine IF the oil is changed regularly (NO-SYNTHETICS), keep the RPMs normal, and a fully operating air filter is monitored. Any kind of engine will see a shortened life expectancy due to dirty oil, leaking air filters and excessive highrpms.