Author Topic: Surging engine  (Read 4021 times)

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#20

Offline RogerG

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Re: Surging engine
Reply #20 on: 29 July, 2010, 06:20:45 AM
Hi Frankie

FLAPPER MOD – remove the air cleaner cover and you will see a tube connected to a round metal object (Vacuum valve) – just remove the tube and seal up the end of the tube (I screwed a bolt into mine) – that’s all that’s needed to be done.

I also got Revs that changed on their own (Revs around 2,500 to 3,500) and I believe it was due to a faulty/dirty “O2 Sensor”. As a test, you can disconnect the sensor, ignore the “FI” warning light, and give the Bike a brief run. If it cures it, then you can try to convince your dealer to replace the sensor under warranty (I failed to convince mine). I ended up fitting an O2 Eliminator which solved all my problems.

The O2 Sensor connector is under the right hand side rear cover – see pic below.

Every mistake begins with a choice

#21

Offline RogerG

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Re: Surging engine
Reply #21 on: 29 July, 2010, 06:46:24 AM
Frankie, just a after thought - maybe the dealer disconnected the vacuum tube in the air cleaner box, to get better access to the air filter, and forgot to reconnect the tube - that would give you a permanently closed flapper valve and an air leak - maybe worth checking.
Every mistake begins with a choice

#22

Offline Bilbo

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Re: Surging engine
Reply #22 on: 29 July, 2010, 08:16:05 PM
Well it seems this is the same as my thread Hesitant engine problem
It’s interesting to note in the link
http://www.rogueracing.org/flap.htm
That it states

When the bike is breathing through the 2 small openings it is bringing in nothing but hot air from the engine bay.


My problem started with all this nice hot weather and driving in London

It has been a lot better after re-filling the petrol tank

So just maybe I have had two problems now it’s only at just below 3000rpm and does start when the bike has warmed up and worse with the fan on.  Less traffic today and I only noticed it a few times

So a little bit of superstition that might be a load of tosh :087:

Just maybe the fact that the restricted air flow from the engine bay is a tad too hot in the current weather it draws the same air volume but has less mass of air making a leaner mix.  The fuel management sensors should cope with that but maybe the engine management is not quick enough in playing catch up hence the hesitant or surging effect.
 
This would be worse with my GT’s lower fairing

SOME engine management systems in the car world have self learning programable chips and change the basic fuel and ignition mapping slightly relative to the air temperature extremes and the way the cars driven but that happens over miles it’s not an instant response.

I have no idea if that true with bike

Whatever, as the bike is under warrantee I am reluctant to start disconnecting bits so I think that I will live with it

PS how do you do those nice quote blocks :465:

#23

Offline FRANKIE FOSTER

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Re: Surging engine
Reply #23 on: 29 July, 2010, 08:25:19 PM
well you guys never cease to amaze me  :046:me bikes smoother,more responsive,no vibes through the bike at all,brilliant in low revs in any gear ,thank you all ,though just wonderin if this could cause any longterm damage well done guys cheers :031:

#24

Offline Roger

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Re: Surging engine
Reply #24 on: 29 July, 2010, 09:04:21 PM
*Originally Posted by Bilbo [+]

PS how do you do those nice quote blocks :465:

What...like this?
Reply to the post, and if you scroll down you see previous replies, and each one has an Insert Quote button in blue at the top right of the quote.
it does what it says on the button
18 BMW R1200 GSA Triple Black
03 Silver FZS1000
58 Black CBF1000 GT  gone to a new home.

#25

Offline Bilbo

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Re: Surging engine
Reply #25 on: 30 July, 2010, 07:03:29 PM
Ah

As I click on reply I have never noticed it  :034:

#26

Offline shearsey

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Re: Surging engine
Reply #26 on: 30 July, 2010, 09:36:34 PM
I've had this issue with my bike since new and just thought it was a characteristic of the CBF. After reading this post I popped out this afternoon and did the mod. Five minutes later I took the bike for a test ride, and problem solved.  :028:

#27

Offline Bifferman

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Re: Surging engine
Reply #27 on: 31 July, 2010, 05:29:29 PM
*Originally Posted by think.bike [+]
Whilst having a chat with the service guy at Pidcock Honda Long Eaton I mentioned the surging engine issue and all that I'd done to cure it.

He sent one of his mechanics (who runs a Biffer, just returned from a euro trip on it) out on my Biffer, guess what? no fault found, the 'surging' that I describe is indeed a feature of the bike, FI, emission and noise control, coupled with me coming from a 'carbed' bike.

I'll put this to bed now and enjoy the Biffer knowing that it's 'Normal'

(whilst there, had a demo on a Viffer 1200, that did the same thing!)

Cheers

I have just done a long test ride on the auto VFR 1200 and no such thing on the one I rode.  Are you sure you are not confusing engine surging with the occasional snatching you get when the throttle cables have play in them.

Andy

 :149:

#28

Offline Bilbo

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Re: Surging engine
Reply #28 on: 31 July, 2010, 06:22:13 PM
Well mine was much worse on Friday and as it was not a really hot and day with little traffic going into London I think you can forget my too hot idea.  Its odd as it was much better on Thursday.

Hi Bifferman

I did checked for play last week in my throttle cable as I also thought that might be the problem and it seems fine and as I have now near emptied another tank of fuel so bad fuel is now an unlikely option.

It was fine until 200 miles ago and as I said on my thread my Honda dealer found no faults

So I might try the flapper valve tomorrow err the last time I worked on a bike was 30 years ago.  Still that assumes mine is the same problem.

#29

Offline Bifferman

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Re: Surging engine
Reply #29 on: 31 July, 2010, 06:31:49 PM
I really feel for people who are affected by any form of surging engine, IMO it should not surge.  Mine has just started snatching, happened immediately after the 3 year service when an over eager techie I think adjusted the Service Manual recommended level of cable slack back into my setup :232:  I will have to set about carefully removing that slack cable again - my preference is to have almost zero slack in either the open or return cables, with that I get no snatching at all.

Andy

 :149: