zr 700.. issue with spark when gets cold

[ethan77]

I can ride this thing just fine but if it is out side and try to start it.. it starts and idles fine but once i give it gas it seems to run on one cylinder. I pull it into the garage and warm it up and I can run it outside with no problems... once it cools down then it goes back to running like [PoorWordUsage]... any ideas? It rode fine all day saturday then saturday night hit and I could not get it to go like it should... no power.. idles fine but thats it... could it be the sensor in the handle bar or a coil pack? not to good when it comes to electrical issues

[Steve Bakken]

Been having the exact same issue with my wife's EXT. Must be a cat thing. Did it 4 years ago on a -25 day. Had the coil tested and they said it was ok. Did it last year in Michigan on a -20 day. I replaced the coil, wires, and cap this fall, just in case, and guess what, last saturday it did it again. It seems to get better or worse depending on whether she's on the gas and at certain speeds. Almost seems to be related to the throttle position. Could be the button on the throttle. Anyone know what the wires coming from the carb are for?

[Macgyver55]

The throttle position sensors on the carburetor can often cause this symptom. I'd suggest making sure they are in "sync".

Its a bit technical, but not difficult. Start by removing the airbox so you can see, or at least feel the carb slides in the barrel of the carb. Look, feel, or measure how much each slide is open. Both slides must be open the same amount, and must begin moving at the same time when you squeeze the throttle. If one is open more than the other, first back off the idle speed screw to make sure the slide is free to drop more. If it doesnt close more, then turn the cable adjuster on the top of the carb in to allow the slide to drop until they are even. Next, (most important step) sqeeze the throttle very slowly and watch/feel to make sure they move at the exact same time. If not, tighten up the cable on the one that doesnt move. It takes a bit of trial and error to get them right on but the result is a better running and performing machine.

Most often this adjustment gets out of whack when someone takes off the top of the carb for cleaning etc, and inadvertently changes the cable slack adjustment, or adjusts the idle speed screw on one carb but not the other.