1) do you have coolant in the oil, oil in the coolant or coolant being forced out of the overflow when you're riding? Sure sounds like head gasket, cracked head or cracked cylinder (gasket most likely)
2) if it's jetted stock then you need the filter, snorkel and airbox lid installed or it won't run well at all
3) good job on the reverse switch wire - now disconnect the parking brake switch wires as well to make sure they don't become an issue.
You seem to be describing issues with just one of the quads now... what happened with the other one?
RE: starting with start button - pull in the clutch lever when starting - the CDI needs to see either that you're in neutral OR that the clutch is pulled before it will send voltage to the starter relay (solenoid). Since your neutral light is not working, I'm going to assume that the CDI doesn't see that you are in neutral either.
SO, when pulling the clutch does the starter now crank or do you hear a CLICK from the relay when you push the start button?
If no starter:
does the starter still turn the engine over when you short across the two large starter relay lugs with a screwdriver - if not you have battery or battery/starter cable issues (or starter or engine issues, but not as likely}.
If no click:
1) to start with the switch you must have 12V at the yellow/black wire on the starter relay and it must stay 12V when you push the start button.
2) Also you must have 12V on the blue/white wire at the relay and it must go to near zero when you push the button.
RE the neutral light - the neutral switch is next to the reverse switch and has a light blue wire attached to it with a screw... make sure the attachment is tight and clean. Grounding the attachment point (with the wire still attached) should turn on the light.
A lot to absorb, but let us know where you end up after going through these suggestions/tests
AND - Welcome to the forum!
'01 660 Raptor, Burgard +2+1 arms, YFZ Shocks, LSR anti-vibe, CTR pipe, jetted, K&N
'01 Polaris Scrambler 400, K&N
'02 Honda 400ex, Big Gun pipe, jetted, K&N, Lonestar +2 A-arms, Lonestar anti-vibe
'04 Suzuki LTZ400
'16 RZR XP4 1000 Turbo
Last edited by QuadManiac; 05-15-2019 at 02:11 PM.