'14 TE310R idling rpm up and down

Hi All,

I have an issue with my '14 TE310R whereby the idle RPM goes up and down. When cold the bike stays running but the idle increases RPM then drops RPM. Even with the idle knob pulled out (choke?) the idle does not sit reasonably steady on cold start.

When the bike heats up the the idle still goes up and down except if you sit idle for a short time it eventually stalls when the RPM falls (even in neutral).

Is it normal for the idle RPM to go up and down? If not then does anyone know the likely cause?

My bike it pretty much stock apart from removed O2 sensor.

Thanks,
Daniel

Hi! mine ´14 310R do the same, but only if the choke is ON. Without choke, warm or cold idle is perfect (the bike idle is near 2000rpm´s, pretty high)
Check the map your ECU had installed on it...

I haven't had the maps changed on the bike so it should be the stock one. Is there a way i can tell what is installed on it?

Check the intake boot for leaks, sounds like a varying amount of air is coming in when and where it's not supposed to.

Only with choke on does my bike experience this. If the bike is stock except for pulling the sensor then first you need the open air filter cage to have it run somewhat reliably without stalling at every stop. Pulling the sensor with the stock map may not be doing anything but the stock map may be looking for sensor input. Verify what is really stock and what may have been changed: Cannister, filter cage, velocity stack, cat and finally map. Without every one of the above itemized it is hard to isolate and help. Getting it to run well is not a piece by piece experiment but pretty dialed in at this point.

Sounds like air issue...either leak or restriction.

The O2 sensor connection has been terminated with some sort of resistor (sorry..new to these bikes only had 310 for a couple of months). In terms of the intake, the cage and guard have been removed (in red below) and the more open cage is present (in green). The rest of the components to the throttle body are the original ones. The cat has also been removed.



Ill check the intake boot for leaks. I am guessing it's going to be on the throttle body side.

Intake manifold has a threaded hole or nipple. See if still capped/plugged.

Yep it's still plugged

Check the idle screw/choke for amount of turns out. I forget how many turns from closed it should be but the manual should define it. Has the bike sat awhile... Enough to let the battery discharge? Does bike run OK off idle. Can you add some revs and ride it without issue? That may show a battery on the edge of needing to be replaced or fully charged. Otherwise maybe clogging injector or some bad fuel. Still can be a cracked manifold but on a new bike pretty much hard to imagine it would crack this early. Also make sure both leveling petcocks are open on the gas tank as well as seeing that your tank vent is not kinked/blocked.

what about the velocity stack (#2, red plastic trumpet looking thing inside the air filter). In stock mode (USA models) this thing is severely restricting the air flow; but it's made to be modified by cutting about 3mm off the little end, or even left out. verify each thing in Johnrg list so you know where you're at (and so will we).

The cold start knob is supposed to be at 34 clicks out IIRC (and I probably don't). I think the manual has it backwards too-> more clicks out is higher idle. again IIRC.

Couple of weird points: I do not know how the "choke" works. And on USA bikes, the O2 sensors is not used but is installed.

nothing here would directly cause a hunting idle, but you (we) need a foundation from which to start. btw, what's the mileage on the bike, mpg, repair history, mods?

good luck.

the velocity stack is just straight through (no restriction). The diameter is the same size as the throttle body. Bike has about 1900km on it (~1180 miles), no other mods apart from what mentioned already. The only repair so far was a water pump leak which was letting coolant into the engine oil.

The bike runs fine off idle. After taking it to the dealer he has re-flashed the ecu which has made a huge difference to the idle (it's much more steady now). Won't be able to test it out fully till the weekend.

I do think the battery might need to be replaced as it doesn't take much before the estart struggles to turn over. estart only works in neutral. has no hope with clutch in with 1st gear.

Thanks for your help so far. I'll let you know how it goes after the weekend ride.

Well? How's it go?

Wasn't able to head out last weekend due to weather. Aiming for this weekend so I'll post after the ride

Well the bike went well. There is some small movement in the idle when hot but no way near amount as before. Put a new lithium battery in as well so estart is working much better also.