I would check the spark plug to make sure it isn't too fouled, but I believe it is not the cause of the problem you are having. There is a ignition module type thing in this bike I do not know to much about that could be the issue or you have a vacuum leak somewhere possibly.

The oil filter on a LF250 is on the right (passenger) side of motor and has three allen-head bolts retaining it to the motor. The oil filter cover is branded "LIFAN". Inside the cover you will find a rubber O-ring seal on the inside edge of cover. Centered within the cavity is the oil filter or "strainer" as more correctly described. I recommend using brake/parts cleaner to thoroughly clean the debree from the strainer. If yours is a paper type filter it must simply be replaced. Re-tighten the cover snugly. Thats about all for the filter.

my mso was pretty thick. The problem I had was that I did not have a purchase order to go with the MSO. I was able to obtain one from the dealer and NV DMV registered the bike.

I just bought a 05 250. I am told by the person I bought it from that it takes yamaha parts. Not only am I new to Lifan, I am new to motorcycles.

Last night, my chain fell off. It was no big deal to put it on and I tightened it up when I got home. It seems to be straightforward on tightening the chain but I am using "common sense". This doesn't always apply. Is there a maintenance section to this forum? Is a service manual available for this bike?

Nice to meet everyone and I will be here often, I think.

Pat

Well I just serviced my chain today, after 1200miles on the odometer it appears to have stretched a bit. basically on the end of frame on either side of the rear tire there are two nuts. You have to loosen the axle nut then loosen the rear-most nut on the end of the frame on each side of the tire.
Then use the innermost nut to draw the axle to the rear, tightening the chain. Use a tape measure to determine that the center of the axle is the same distance from the rear of the frame. Yuu should have about 1/2in of play with no added weight on the bike with both tires on the ground. When a rider gets on the bike you will notice the chain becomes taut.

Now that you have adjusted the tension of your chain you would be well advised to lubricate it with some quality chain wax. I used the castrol brand that can be had from your local motorcycle shop for  $10-$15.

I maintenance my chain every 2 mos due to the high amount of miles I ride my motorcycle.