2008 Suzuki King Quad 450AXI No Start After Battery Overheating

[QuadRunner]

I'm hoping someone can help me diagnose my 2008 King Quad 450 no start

A couple days ago, after running for a few hours at low speeds (2-3mph wiping weeds), seat got hot, motor started to stumble, and we turned it off. Gave it a few minutes to cool down, turned on key, dash flickered, then lit up, I tried to start, but it did not turn over, dash died like the battery was dead.

Quad acted like it was overheated, but I noticed a lot of heat coming from battery area. Checked battery voltage, showing 10.5 volts. 

I had something similar happen last year, and it ended up being the regulator/rectifier. It killed the battery that time too.

So, this time I pulled the battery, it stayed quite warm for over an hour. Put it on trickle overnight. Next day it showed over 12 volts. Took it to advance auto and had it tested. Bad cell. Bought new battery.

Installed new battery. Now when trying to start, it seems normal, turns over, and begins to start, but immediately dies.

I have ordered a new regulator/rectifier that will get here tomorrow. But today, I pulled the regulator and tested it according to the service manual. Ran a diode test using my multi-meter between all the pins on the regulator. They were all within range according to the service manual.

Unplugged stator, and tested it. Showing 1.9 ohms between all pins. This is out of range. Should be .1-1.0 according to manual. However, I have a brand new spare stator, and that one also reads 1.9 ohms. I'm guessing my multi-meter is the problem?

Used a paper clip to jump pins and put the dash into "dealer mode". Shows C00. No codes.

Last time the regulator failed, I was able to remove the negative battery cable and do a leak test with the multi-meter. I observed a voltage leak, and when I unplugged the regulator, it would stop leaking. This made it clear to me that the regulator was the problem. This time, no voltage leak. Also, last time the regulator failed, it would still run fine with a new battery, it just wouldn't charge. Now it won't stay running for more than a second. I'm thinking this could be something else. Any ideas?

 

[Mech]

"Installed new battery. Now when trying to start, it seems normal, turns over, and begins to start, but immediately dies.".

Well.. dying straight after start up, disregarding the battery issue, I'd be checking the fuel pump and pressure.

Running lean could make it run hot. A burning out/seizing fuel pump could bugger the battery perhaps..

Edited August 4, 2022 by Mech

[QuadRunner]

Thanks for the reply. I received the new regulator today. Plugged it in. No change.

I pulled the spark plug, and checked for spark while hitting the start button. Spark looks good.

I can hear the fuel pump relay click when the key is turned "on", and I can hear the fuel pump priming before attempting to start. However, the motor barely stumbles before dying.

Seems as though I lose either fuel or spark immediately after starting. I suspect fuel, because I don't smell much fuel after these start attempts. 

I'll try to get a gauge and fittings so I can check the fuel pressure. 

At the moment, I'm wanting to try jumping the fuel pump relay so that fuel constantly runs when the power is on. If I'm able to start the motor, and it continues running with the fuel pump relay jumped, that would suggest that the relay is not getting the signal to pump once the motor is started. 

I read somewhere that the signal from the ECM to run the fuel pump after startup is on a different circuit that the one that primes it before starting. Maybe I fried my ECM when the battery failed?

Does anyone know which pins to jump on the plug for the fuel pump relay?

[Mech]

Yup that's right, they prime them for a few seconds when you go to crank it over, and after it starts and you let the key off something like the crank or cam position sensor signals to keep the pump on.

Your test is a good one.. But then you need to read up on how to get the trouble codes out of the dash, or what sensor it is that keeps the pump running.