GS Back fire?

Dragon

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• Sep 21, 2003

• #1

I have fitted the "Y" pipe to my GS 1150 adv,

and now the dam thing backfires on the over rev,

any one know why this is????


Dragon.

 

MikeO

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• Sep 21, 2003

• #2

Dragon said:

I have fitted the "Y" pipe to my GS 1150 adv,

and now the dam thing backfires on the over rev,

any one know why this is????


Dragon.

Click to expand...

Because you fitted the Y piece.

Do a search on 'Backfire' and settle down for an evening's reading.

Ensuring you have no air leaks in the joints will help, but if you ditch the cat, you're going to have to live with some backfiring....

Mike

 

Deleted account 231205001

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• Sep 21, 2003

• #3

My 1100GS backfires on the 'over-run' after a hard run. Standard exhaust, no chip or K&N. At first I hated it, but now I'm almost disappointed if it doesn't backfire. Is it because it's running lean ????

 

Ming

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• Sep 21, 2003

• #4

It cannot be because you are running lean because there would no air/fuel mix to ignite would there . might have a leaky seal in the exhaust letting in fresh O2 so it can light !!

 

Steve

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• Sep 21, 2003

• #5

Dragon said:

and now the dam thing backfires on the over rev,

Click to expand...

Good fun innit? Especially in tunnels....

 

ralphy

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• Sep 22, 2003

• #6

Re: Re: GS Back fire?

scurrell said:

Good fun innit? Especially in tunnels....

Click to expand...

....or passing a dozy cow in an open-topped Mazda who, whilst chatting away on her mobile, changed lanes in heavy traffic on the M5.... into the space thoughtfully provided by my heavy braking..... causing me to inadvertantly hit the kill switch and, realising my mistake, switch it back on straight away whilst alongside her...........the resultant backfire caused her to drop the phone.
How inconsiderate of me.........

 

Dragon

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• Sep 22, 2003

• #7

Nice one ralphy

PMSL<@ Ralphy's story, lol, lol, lol ,

 

grandtrousers

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• Sep 22, 2003

• #8

I am getting a Y piece solely for the backfires (not interested in any power gains at all!! )

 

Murray

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• Sep 23, 2003

• #9

1100gs BACKFIRE

Big Lad said:

My 1100GS backfires on the 'over-run' after a hard run. Standard exhaust, no chip or K&N. At first I hated it, but now I'm almost disappointed if it doesn't backfire. Is it because it's running lean ????

Click to expand...

To big lad

From murray. mine backfires. bmw have been trying to find out why. had there top man on the job ,loads of diagnosic checks ,test rides and approx 4 visits to there workshops. there answer is ... it is a characteristic of the 1100 gs try using difference brands of fuel. we are not talking pops. were talking f...ng great bangs. like to here about yours.

tel 079560587360 or post reply.

murray

 

Mick Fagan

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• Sep 24, 2003

• #10

My experience with the 1100GS is that if one doesn't have an oxygen sensor then it will backfire.

The reason is simple, you back off and the fuel is shut down. As the revs drop to a certain point the computer switches the fuel back on.

Because there is no oxygen sensor in the exhaust pipe, the computer cannot be told just how much or little fuel is going down the header pipe, therefore the computer drops a fair whack in to allow for error (so to speak) realises it's error and shuts it down again then opens the fuel again. This of course happens in milleseconds but the result is a bang or popping on moderate throttle openings.

It usually happens just as the tacho drops below 3,000 rpm.

Mick.

 

Murray

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• Sep 24, 2003

• #11

backfire

to mick fagen. so can it be sorted? is it damaging the bike? it has developed over 6 months. it happens usualy when i am riding hard. if i change to a remus end can will it make any differance?

murray.

 

Mick Fagan

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• Sep 24, 2003

• #12

Murray, I don't know whether your particular problem can be sorted.

In Australia all 1100GS bikes came without a CAT this meant that they had no oxygen sensor. The system was designed with a sensor originally so one can be fitted.

A local bike shop has made a speciality of adding oxygen sensors to 1100GS bikes. One of my mates has had one fitted to his 96 1100GS and according to him, the backfiring has stopped. He has an aftermarket Staintune exhaust the same as me.

This might help you.

Mick.