flat spot under hard acceleration

Having Problems with your BMW R1200RT/R1250RT? or have some Maintenance and Service questions?
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Tom 2
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flat spot under hard acceleration

Post by Tom 2 »

Hi everyone
Bike hesitates on hard acceleration at around 3000 and 6000 rpms. runs fine other than that.
bike is a 2011 38000 miles.
Just bought and fitted 4 new coils thinking it was that.
Today going to buy some injector cleaner to run through the tank.
valve's in speck, exhaust flap working, Throttle Synchronization done by Bmw.
Any idea's please i'am stumped
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Randyjaco
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Re: flat spot under hard acceleration

Post by Randyjaco »

I had a similar problem with mine. I tried all sorts of fixes over several months to no avail. The final solution was replacing the fuel pump. The problem totally disappeared.
jaapvanthoff
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Re: flat spot under hard acceleration

Post by jaapvanthoff »

That can bee, + do not forget to change the fuel filter.
Tom 2
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Re: flat spot under hard acceleration

Post by Tom 2 »

Thanks guys.
Am I right in thinking this doesn’t have a fuel filter. Some kind of lifetime gauze in the tank.
If it has where is it how do you change it.
Will look into fuel pump price :|
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Doctor T
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Re: flat spot under hard acceleration

Post by Doctor T »

Have you balanced the throttle bodies?
Trust me I am a retired Doctor and lecturer at Oxford University of Structural and Mechanical/Electrical engineering.
"Blessed are the cracked, for they shall let in the light". Groucho Marx
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Randyjaco
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Re: flat spot under hard acceleration

Post by Randyjaco »

I agree about the fuel filter. The stock one was crap. I got an aftermarket pump that came with a real canister fuel filter.
Tom 2
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Re: flat spot under hard acceleration

Post by Tom 2 »

Fuel pump and strainer £51.76. Think I’ll order that for peace of mind.
Balance throttle bodies. Is that the same as throttle synchronisation?
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Randyjaco
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Re: flat spot under hard acceleration

Post by Randyjaco »

Let us know how it turns out :thumb:
Tom 2
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Re: flat spot under hard acceleration

Post by Tom 2 »

Will do.
Out all weekend on her. Start taking her apart Monday
Tom 2
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Re: flat spot under hard acceleration

Post by Tom 2 »

I don’t have the correct tool to unscrew the top of tank. Do I need one or is there some trick or will it unscrew by hand. This is a new place on the bike I’ve not been :|
Tom 2
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Re: flat spot under hard acceleration

Post by Tom 2 »

Update to my running issue
Fitted new fuel pump and filter. Took injectors out and cleaned and put back together.
Absolutely brilliant. The bike runs with no hesitation at any Rev range. Was definitely fuel problem. Although it ran a little better with the new coils. But that wasn’t the fix. Thanks to all
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