2005 Rincon 650 major issues?!
Hello all and thanks in advance for any help on this topic! Friend wants to trade this bike for a couple of pistols (good trade for me) if I can figure out what is going on with it. I’ll have detailed diagnoses in the next few days when I get a chance to put some tools and testing to it. I’m writing on here because my initial inspection has me baffled and I’ve never run into this particular issue before with ANY gas sucking engine.
This started with him asking me to see what was wrong with his ATV. Says he was riding it and it died all of a sudden. Turns over but will not start/fire. Seemed simple enough. He said he has had a “tick” since buying it used. Which I immediately thought of a timing chain on a Honda I used to own.
Got to his house and turned it over, sounded normal, no internal knocks while turning over, figured I’d have it running in no time. Put some starting fluid to it, jumped over but barley like there is a spark existing in the cylinder but no start.
(This is the important part) Put my hand over the intake with the filter taken off thinking I would manually choke it. Turned the bike over, with absolutely ZERO psi sucking at my hand??? On a 650?! 🤯. Checked if carb came loose from intake manifold It did not. Put my hand over exhaust very tight NO PRESURE WHILE TURNING OVER. Had a friend put his hand over the intake and mine over the exhaust and had him move his hand to open and then close off air to the intake. No pressure from either side.
I’ve thought about the process a motor takes to run and have only come up with possible hole in piston, broken timing chain, broken camshaft (but this would come with some kind of noise or irregularity) bad valve seat on both intake and exhaust? I can’t find squat on these particular symptoms online or here on this forum. SOMEONE PLEASE HELP. As I said, in a few days, I will bring compression tester, multimeter, spark plug, and tools over there to further diagnose so bear with me. Thanks for the help!