NEED HELP WITH MCX270

[YAMA S]

Just got out for first ride today. It ran awesome all morning other than water temps where getting to hot 190-208 on the trail. Got to first big play area and let it cool all the way down. Made 3 short runs just to get the feel of the machine and it ran perfect. I let it cool down again. Made a longer climb it ran awesome, second long climb ran perfect till last 100ft. At about 75% throttle it seemed to stumble and then feel like a slight loss of power(water temp was @ 200 when I turned out). Came down the hill parked next the guys for about 10min. Then the sled wouldn't start.... It seems like the starter wasn't spinning as fast as normal 225rpm on the dash. Checked ALL the wire connections and found no problems. After about 1.5hrs of messing around it finally started. I put side panels back on didn't shut it off. Went to get it out of the bowl we're in and ran fine for (temp of 205)1000yds. Soon as the boost came on it fell on its face and wouldn't go over 5500rpm. Got to the top of the hill and the sled died and I couldn't get it started again. Had to leave it on the mountain as we lost day light didn't have a big enough sled that could pull it over the next hill. Going up in the morning to recover it. Any thoughts of what the problem mite be? Would rather ride it out than tow it.

 

[YAMA S]

This is a shot in the dark.... Could it be vapor locked??

 

[djones000buck]

If it's a vapor lock the air bleeder is right behind the battery, can take the cap off and open it up, while putting more coolant in the radiator.

You can also run diag (assuming you are running factory ecu). Diag code 21 is coolant sensor, diag code 51 will test the fans, but you didn't mention any fault codes. If the ECU was sensing too hot for operation it should be shutting you down and flashing a fault.

Alternatively take a set of vice grips with you and a few zip ties.. Clamp the fuel line going to the injectors in your intercooler, and zip tie the vice grips to the plastic headlight assembly where it connects to the front subframe (I've done this and finished out a days riding on low boost) and unplug the MCX controller (you can leave the controller plugged in it just wouldn't isolate any potential electrical problems if that were to be the case). You can run around 8 psi boost pressure on the factory fuel system. So you either have to be cautious of the throttle on your way back not to boost over 7 or 8 pounds, or turn your wastegate in about 5 turns or so (3.5 turns does it on my 240 kit), to mechanically limit it to 8 psi.

Do you have a headshim installed or running the good stuff?

 

[Thistledoo]

Why is it running so hot?

Should be 125-150 all day if there is any type of loose snow. If it gets to hot it will shut down on its own. Did it give u the temp light?

The mcx black injectors are known to screw up, either stop working or stick open causing a flood condition. Like he said clamp the fuel line off to them to rule that out. Take a set of plugs up with u and the tools to get into them in.

 

[Linc]

It could be a boost hose with a leak too, or what happened to mine, snorkel over the summer sagged because the cover put pressure on and it make a slight kink in the hose where it goes through the heat shield, and as soon as the boost came on, it suck shut and cause the engine to stumble and die if i was on it too long, and a bitch to get running again, because it severely chocked it out.

 

[YAMA S]

djones000buck
Thanks for all the info. Yes on headshim running 92 non ethanol.

Thistledoo
Not sure why it runs soo hot. It ran hot when it was supercharged also.Light never came on for heat. As for injectors not sure what color I've got.
Stupid? How do I get the codes to pop up?

 

[djones000buck]

Diag is accessed by turning the key off and leaving the kill switch to run position. Press and hold the reset and select buttons on the display. While holding, turn the key to the run position and continue holding for 5 seconds or so... You'll see diag on the screen, as a side note, the fuel pump should be unplugged as in diag code 36, 37, and 38 fire injectors 1 thru 3..

But in diag mode, you should see 01 come up first if you go up first to display number 70 is the control number reference, if there is a number below the 70 that is displayed, that's your fault reference.

 

[djones000buck]

But I agree w/ Thistledoo and Linc, more commonly are either fuel or boost leak issues. Also, a cracked header pipe.

How does your coolant look/smell that might lead you to questioning the condition of the headshim. But you'll have to get it running to begin troubleshooting...