Most likely you are hearing piston slap. Probably time for a new top end.
stock gearing 60 mph
.5 L
the ktm 85sx. it beats all of the others
In 07, the KTM 85SX MSRP was $4,298.
with stock gearing 60mph
The CRF150R generally has more power compared to the KTM 85SX due to its larger engine displacement and design aimed at providing higher performance for older youth riders. The CRF150R features a 149cc four-stroke engine, while the 85SX has a 85cc two-stroke engine. However, the two-stroke engine of the 85SX delivers its power differently, often providing a more aggressive power band. Ultimately, the choice depends on rider preference and intended use.
32:1.
400cc 5wt fork oil
5.1 on my 2004 model
YES
About 5,000 new but around 2,000 if you find a pretty used one
The fuel oil ratio for a 2009 KTM 85SX is typically 50:1, meaning you should mix 50 parts gasoline with 1 part 2-stroke oil. It's essential to use high-quality 2-stroke oil designed for high-performance engines to ensure optimal performance and engine longevity. Always refer to the owner's manual for specific recommendations and adjustments based on your riding conditions.