Oil blew all over CVT !  By  4950cycle (Read 1,175 times)

JCL MP250A Lihai 257cc powered / Thank you very much. I will certainly have a look see. Did you get that nipple out ?

If there is a lot of blow by the crank seal behind the Variator can get blown out. Excessive engine vibration can cause it to walk out. Since you lost drive you need to pull the CVT cover to clean up the mess and replace the belt regardless of the source of the oil as a drive belt once it gets oil on it will not last very long and as it starts to come apart belt cords will wrap around the drive shaft destroying the oil seal behind the variator. Hopefully the oil has not gotten inside the clutch and soaked into the friction pads.

By the parts listings on Parts for Scooters they are press in seals which can be installed with cautious use of a hammer and a length of pipe that is the same outside diameter as the seal and long enough that you will not accidentally damage the end of the crankshaft.

Be sure to verify the correct size seal used on your bike as there appear to be a few different sizes along with a smaller one for the right side of the bike behind the magneto cover.

Yes others have occasionally had crank shaft seals wear out or get damaged by old or defective belts that are in the process of failing.

Yep hoses and purge systems do get plugged by old oil or collapse from the heat once the blow by gets bad enough. The also get capped by some when trying to bypass evap systems.

When the pads get soaked they have to be replaced however if they are just smokey from a oily fog you can many times get by with using some brake lining cleaner. Its a judgement call.

No matter what though the CVT case and any contaminated components needs to be completely cleaned out of all oil along with the belt and possibly the rollers replaced regardless of the source of the oil.

4950cycle. In the manual I mentioned earlier I would look at this link:

www.manualslib.com/manual/908522/Linhai-2004-Atv-260.html?page=96#manual

In the top right of the page, enter 96 in the page you want to see. This should take you to the crankcase section (section 3.10) for the 260-400cc engine with diagrams, pictures and step by step instructions.

If its already open then you should be able to clearly see where the oil is coming from. Have you removed the variator yet? The seal is behind it and cannot be removed by going up from underneath like some of the older car engines as it is a one piece pressed in seal like on a wheel bearing, You may find once the variator has been removed that the seal already popped out and removal is not an issue. Yes you can cautiously hook the seal and pull it however you have to be very careful about nicking the shaft where the seal rides or damaging the bearing and its cage behind the seal. There is only about 1/8 to 3/16 of an inch of space between the face of the seal and the bearing behind it so you can't use a screw with a very long point if you go that route. You may want to get the replacement seal first so you can measure exactly how much room you have to work with before drilling.

There is a lot of danger in causing damage to the metal surface of the shaft where the seal rides and while the bearing is on the crank and is located inside the crankcase the parts diagram in the manual does not clearly show how much clearance the shaft has where it goes through the case to the seal area or how much separation there is. Caution is still advisable until you have at least the rubber center of the seal cut out and can see how close and exposed the bearing is behind it.