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Offline bctz123

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F850GSA engine cuts when full gas
« on: October 16, 2020, 10:35:30 PM »
Hello guys, I have a 2019 BMW F850GSA and today after 14k km on it, I've noticed something very strange.

When I go full gas, the engine cuts down, it does not accelerate for 2-3 seconds, and then it accelerates as normal.

This only happens when full gas, if I go 80% gas, it does not happen.

It lasts for 2-3 seconds, then it picks up the rpm.

One time I noticed that for example if I'm in second gear, 3000 rpm, I give it full gas, it goes into red instantly and the screen flashes for 2-3 secconds and then I goes to 4000-5000-6000 RPM.

I find this very strange as this is an almost new bike.

Do you have any solutions before losing 2-3 hours at the BMW dealership?

Thanks!

Offline Tioli

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Re: F850GSA engine cuts when full gas
« Reply #1 on: October 17, 2020, 03:55:07 AM »
Is there any chance you are over revving and the rev limiter is coming in.

I think I have noticed on the rare occasion the red flashing at about the same time as Iím shifting. I presume if I didnít change to the next gear the rev limiter would come in and stop the motor from revving any higher   
Hindsight is a terrible way to learn Iíd rather be gifted

Offline bctz123

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Re: F850GSA engine cuts when full gas
« Reply #2 on: October 17, 2020, 07:23:01 AM »
Thank you for the response.

When I do this I'm in the 2nd or 3rd gear, mid rpm, 3-4000rpm. And it cuts the gas, similar to when you pull in the clutch. Then it picks up without me doing nothing.

I will try to film it tomorrow with my GoPro.
« Last Edit: October 17, 2020, 07:51:52 AM by bctz123 »

Offline SnoDrtRider

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Re: F850GSA engine cuts when full gas
« Reply #3 on: October 17, 2020, 11:40:34 AM »
If you have quick shift and are touching the shifter this could happen. Try unplugging the shift sensor to see if the problem goes away.
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Online Matty589

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Re: F850GSA engine cuts when full gas
« Reply #4 on: October 17, 2020, 02:05:24 PM »
I was thinking the same thing. Are you preloading the shift lever without noticing? This would make the Gearshift Assist Pro think you’re about to change gear and cut the ignition. Just try shifting then immediately moving the toe of your boot to the peg and only bring it back to the shifter to change again. Any difference?

Offline bctz123

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Re: F850GSA engine cuts when full gas
« Reply #5 on: October 17, 2020, 05:45:29 PM »
Thank you for the suggestions. I will test it out tomorrow and let you guys now.

Offline bctz123

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Re: F850GSA engine cuts when full gas
« Reply #6 on: October 18, 2020, 03:57:05 PM »
I went and did a few more tests.

I've noticed that then I'm in 3rd gear and if go full gas, there's this moment 1-2 sec. where it revs it without accelerating, and then in picks up and accelerated. It does not go in red line or something.


In 2nd gear this never happens. Only in 3rd gear.

I saw that there's a bit of a chain slack, so tomorrow I will adjust it and see if this was the issue.

Any ideas?

Online Yorks_Rider

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Re: F850GSA engine cuts when full gas
« Reply #7 on: October 18, 2020, 06:46:40 PM »
Is the clutch slipping? Have you checked whether the amount of play of the clutch cable at the lever is within tolerance?

Offline bctz123

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Re: F850GSA engine cuts when full gas
« Reply #8 on: October 18, 2020, 07:34:15 PM »
The clutch is ok as it was just set up by the bmw service 2-3 days ago.

Online Matty589

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Re: F850GSA engine cuts when full gas
« Reply #9 on: October 18, 2020, 08:11:35 PM »
It’s very unlikely to be fuelling or the engine if it only happens in one gear. I never noticed this on any of my bikes - in fact they have plenty of go for me and don’t come out too shabby compared to a bigger bike. The acceleration certainly isn’t sports bike-fast but it is consistent. What rev range/speed were you in when shifting? Chain needs a bit of slack so if you adjust it, do it in very small steps as it is very easy to overtighten and not that easy to measure the slack accurately due to the big plastic chain sliders.
I think a trip to the dealer may be inevitable. Hard to tell from your description alone, but I’d look at either the gearshift assist or the throttle position sensor - but even then it makes no sense that you’d only experience this in 3rd gear.
« Last Edit: October 18, 2020, 08:13:20 PM by Matty589 »