Bonneville America Forums Forums Technical Forums General Tech Engine stalling on 2011 bike

I've done the requisite 500+ miles on my new America. Only one problem which is a pain and embarassing around traffic. To explain...
I'm comming toward a road junction or traffic lights. I cut the throttle, fully pull in the clutch, change down to 4th then 3rd and engine cuts out. So, started again, I pull in clutch, select 1st gear and engine stalls. I have to give more throttle to get going even before I start to let out the clutch. The idle speed of the bike is set to 1000rpm. When the bike stalls I have not noticed the engine 'hunting' or the bike pulling meaning the clutch is not fully disengaged.

The bike goes in tomorrow for its 1st service and it would be nice for you tech gurus to reply so that I'm not fobbed off with any reply from the dealer (located 50 miles from my home, so don't want to keep returning).

At the start of owning the bike I put it down to engine being tight but I'm sure it should be ok now?

BTW I've owned many bikes and can't remember the last time I stalled one.

Thanks guys (that's a unisex 'guys' )

Alan

This is something which, 1 year on from my new 2010 EFI bike, still catches me out from time to time.
I think its fundamentally due to the comparatievly light flywheels on the TBA( my last bike being a twin cam Harley) and the relatively small ability to conserve inertia in the smaller flywheels.
This means unless you rev it more it can catch you out at low revs.
If its any consolation it doesnt bother me now nearly as much as it used to do-I just ride round it and treat it as a quirk of the machine.
You could always up the tickover speed by turning the little knurled wheel on the side of the injector gubbins.

Al

Hi Alan.

This thread might help - or not. Idle speed should be 1050 but you are close enough not to matter.

Do you have aftermarket pipes and, if you do, the required remap. I'm wondering if your air/fuel mapping is out. When you close the throttle (as you describe when approaching the intersection) the EFI bikes go into closed loop mode. You may already know this, but in case you don't, that means the ECU reads the emissions in the header and adjusts (usually leans out) the a/f mix and pumps air through the AI system so you aren't pumping unburnt fuel into the cosmos. This is also what causes the popping/backfires. It sounds like something is faulty in the closed loop mode - O2 sensors, AI system, or mapping.

Is your bike fitted with the California emissions equip? If so, that is an additional complication that I am unfamiliar with.

Check under you seat and see that there is nothing blocking the air intake or filter - maybe something moving and partially blocking the air intake when you brake. Check there are no leaves sucked into and blocking your air filter.

Bottom line: get your dealer to ride it and fix it. It is NOT normal for then engine to stall while decellerating (closed throttle). You will get a stall if the engine is cold and/or your revs are too low (as discussed in the thread listed above) - but that only occurs when the engine is under load.

Give us a bit more detail on your bike, pipes and mapping.

Thanks for your replies. I have the standard exdhaust pipes. I have not attempted any changes. I'll talk to the dealer and hope he can do something about it. My last bike, which I had for 3 years, was a Honda Shadow 750 which had a very smooth and forgiving clutch/gear change system. UK based so no California emissions equip. This problem has been since the get/go so I guess the dealer needs to rectify as it spoils what otherwise is a fun ride.

Alan

Another thought - bad fuel or water in your fuel? Although you would expect the problem to occur at other times (than just closed throttle).

Mine used to do similar, but after the first service it pretty much stopped doing it.

Nowadays it only happens due to operator error

Faulty TPS? I don't know but just throwin it out there.

Idle speed is critical with the EFI bikes. I'd bump it up to around 1100-1200 rpm or so and see. The tachometers aren't deadly accurate. You need to hook the bike up to the computer to see what it's truly turning over at or use an service tach.

My 2010 used to do the same thing. It's fine with the idle speed raised a little.

H.

I would probably increase the idle speed a bit - put TuneECU on there and you can get digital tach reading off that.

The other thing to suspect is gas - Ethanol can make a significant difference to the fueling. I believe Triumph have been releasing a lot of new maps to accomodate the tolerance to this. It might be worth checking with your dealer to have them load the latest available tune for your bike.

Lastly, try the '12 minute tune' - start the bike, let it warm up completely, then leave it for a further 12 minutes.
This will force the ECM to 'adapt' the idle mixture and possibly improve the idle performance.

Certainly if it's stalling out frequently, grounds to take it in under warranty and have it addressed.