I was riding my ATV (CF Moto CForce 520, 2018) last week bringing cows in to be milked in the morning. While riding, it would occasionally die (as if the key had been turned off), but would start a few moments later. Once the cows were all out of the field and I was following them, my ATV died again, this time it wouldn't start at all, and there was no power to the instrumentation. I knew that my ignition barrel was faulty (when turning it on, the key had to be turned back slightly to off for the points to connect), so I have replaced that, as well as the start solenoid and the auxiliary start terminals due to perished insulation. Even with a new ignition barrel, the power to the instrumentation is intermittent. With the bike running the built-in voltmeter jumps around a bit reading from 12.5-17 volts, which is higher than it should be, particularly for having recently replaced the stator. While running, it sounds like it is missing ever so slightly (maybe one power stroke out of 10-15), and if I move the handlebars slightly, this causes the engine to die. At the moment the engine dies, you can feel the fuel pump relay fluttering. I have tested the voltage being supplied to the fuel pump, and it ranges between normal (12V), very low (2V) and nothing. Sometimes when turning the key on, there is power to the instrumentation and the fuel pump runs to prime, other times there is nothing at all, and other times the instrumentation lights up, but the relays flutter. When there is no power at all, there is no power when turning the key on, but when turning it off it briefly lights up the instrumentation before losing power (this is with my old ignition barrel, a new ignition barrel, and a second-hand ignition barrel). The ignition barrel has been changed, the start solenoid has been changed, the auxiliary starting wires have been changed where they connect to the start solenoid, I've checked the voltage across the fuel pump power supply, I've tried running with a spare regulator/rectifier, I've tried running with a spare ECU, I've swapped around all the relays (they're all identical), I've checked all the fuses for continuity. Any suggestions?

Ever get this one solved?

Hi Matt,

Sorry to learn of the challenges you are getting, it can be very frustrating for a working bike.

Ok sounds like you have taken some preliminary steps to check the basics.

Swoping out relays is a fair trial but can cause some issues, relays like all electrical components can be tested and substituted in this manner but only with caution!

Why.............all electrical components can only be tested, checked and or substituted when under electrical load, testing and substituting in the yard when ticking over is not a finite diagnostic methodology.

So what do you do without an electrical test bench for your electrical components, lets start with the relays, i.e. the micro relays, locate the main beam relay, let the engine tick over in the yard with full beam on, all lights on and hazards. The main beam relay or relays are being tested under load, now substitute with the other relays by the same method.

Outside of this basic field method of load testing relays it is difficult to test the remainder of your electrical components under load in the field without the use of workshop load testers and a diagnostic tool monitoring electrical load.

If it is an ignition coli for example it sounds from your description that it could be breaking down under load on the mountain side when hot and under electrical load, very difficult to check, diagnose in your yard with just a multimeter. 

Take Care GMSAHFR