95 sportsman 400l compression
Finally got some time to really dive into an atv I bought a few years back. The atv seems to have ran pretty good. I have not drove it in about a year. I had to replace the center tightener, and tie rod ends. While I had the plastics off, I decided I would check everything out. I did a compression test on the engine, and I am getting 105 psi. Test was performed with the throttle wide open, and the engine cold. (51 degrees outside tonight). I have the gas tank and battery removed so i cant warm it up to test compression. I put about 2 tsp of oil in the spark hole and retested. Reading 107-108.
On a cold engine, how are these numbers looking? When the engine warms up does the psi increase 5, 10 or more psi?
Like I stated, it seemed to run pretty good, but I just felt like I could never get the carb tuned right the engine seemed to always give me the impression the carb mixture was not right, perhaps this could be why.