2016 Pro RMK 800 won't start.

[ctabernethy]

My Pro RMK 800 sled was running and then just stopped for no apparent reason (!?!). Now, it won't even burp when I pull the starter cord!
I am getting spark and I believe I'm getting fuel (when I pull a spark plug an look at it), but the sled will not even so much as fire now. It is pull start only, no on-board battery or starter. Any suggestions of what could be the culprit?Thank you.

 

[chevy_man]

Compression test.

Pull the injectors and make sure they actually are flowing fuel.

Good spark or just a weak little blip?

I'd check fuel pressure and compression first.

 

[ctabernethy]

Compression = 90psi MAG side & 100psi PTO side. I haven't checked fuel pressure (don't have an easy way to tap a gage into the line), but the injector resistance is correct at about 12 ohms.
TPS is set to 0.705mV w/ butterfiles closed and 0.954mV with the mechanical idle adjustment.
The throttle release switch checks out at 2.15k ohms when released and 6.82k ohms when pushed.
The Stator resistances check out, and the plugs (gapped to 0.027") show good spark when the cord is pulled. All the system capacitors and diodes check out GOOD also.
One curious thing, after the gages are unplugged and the capacitors drained and the sled has set overnight, the first pull on the starter cord causes the headlight to flash ON and the sled will sometimes fire as if to start, but then immediately dies. After this initial pull, the sled shows no signs of life no matter how many times the starter cord is pulled.

 

[05rmksteve]

have you checked the relays and fuse?

 

[ctabernethy]

Fuse is good and relay coil resistance is low (i.e. coil intact).
I think I'm only getting about half a pull on the starter since the cord comes out about halfway before it engages to turn the engine over. Could I not be getting enough starting voltage? Would it be of any benefit to apply 12VDC to the DC PWR 2-pin connector (left side, next to the ECM PWR and GAGE PWR TEST connectors) while I am pulling the starter cord?

 

[05rmksteve]

The relays can get moisture inside of them causing the contacts to corrode. If you put power to the DC power connector you should hear the fuel pump energize for a few seconds then it shuts off once it builds pressure.

 

[chevy_man]

I bet the fuel pump is dead.

But you can't be bothered to actually test, just do weird things praying for a miracle....

 

[ctabernethy]

Fuel pump is looking more like the culprit to me. I applied 12VDC to the DC PWR connector. The Headlamp lit up (so I know I was applying voltage correctly), but the fuel pump didn't make any sound.
I'm going to test/operate the relays to see if they are switching properly. If they work, I'll be ordering a replacement fuel pump. Thanks!

 

[05rmksteve]

put power to the fuel pump itself to see if its working. 12vDC

 

[ctabernethy]

Fuel pump dead on first sled.
Secondary coil wire bad on second sled.
Both sleds running fine now.
Thank you.

 

[Jay]

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