Rather than changing your filter between motos, you can simply pull off the sock and have a clean filter. Some systems allow you to pull of the sock without even removing your seat. Several companies sell them in America and Europe. Castor-based oils separate quickly from fuel and that can cause either spark plug fouling or piston seizures. On very hot days, place a wet white towel over the fuel tank so the sun doesn t heat the fuel.
Cool fuel gives a definite advantage on the start of a race.
Quick Check Grab a set of T-handles and check all the bolts on the bike. This will force you to look over the entire bike, enabling you to find problems such as worn, bent or broken parts. Check the brake pads at the wear-indicator lines scribed on the sides of the pads after every moto because mud races can wear out a set of pads in one moto. Check the chain adjustment. Look for oil leaks at the suspension components.