Rough running finaly sorted.

[Gordon T]

A brief history. 2011 GSa 14800 miles. Full BMW service history.

Picked the bike up and rode it home. During the riding, Im mentaly taking notes as to what is needed to customise it. Gear lever adjusting as well as the screen/seat and brake levers etc. Anyhow Im thinking this engine seems to be running a bit rough, certainly rougher than my last two twin cams. It stalls very easily also. Not to worry, I will be home soon and Im going out that night so any work will have to be done tomorrow.

Next day I have a good look round and cant see anything amiss, ie loose wires/hoses etc, well it was serviced (over a year ago) less than 800 miles ago so why should there be as it would have been picked up before now? Ok what do I look for now? I have all day so will take my time.

Although not connected to the rough running, I changed all the fluids as a matter of course. Nothing to write home about, normal colour etc. Then adjusted everything that needed adjusting so the bike fits. I noticed the rear pads were low so ordered a set up. Test rode it round the block and still the roughness was there although I knew what I had done wouldnt have alleviated it in any way. Next, out with the plugs checking for any burning smells from the coils (nothing). Checked the gaps on the plugs and they were 1.6mm! Hmmm. Got me thinking they should have been changed at the 12000 miles service. The secondry plugs were fairly sooted up. This has got to be the cause of the rough running surely? Anyway a new set of Iridium Denso IU24`s were fitted and a test ride was undertaken, the roughness although still there wasnt eradicated but it was less severe. Bollocks. What now? Must be something to do with the fueling Im thinking. Although I put 20 ltrs of BP 97 fuel in on the way home Im thinking I will have to change it, if only to satisfy myself its not the fuel. Ok drain the tank and replace with Tesco 99ron fuel. Well what a transformation. The engine runs like a swiss watch. No more popping, stumbling or roughness at all. It will pull cleanly from low revs and doesnt stall. Heres me thinking it will have to go and get sorted by the men with a computer. Not this time. Looks like it will have to be the higher ron petrol from now on.

Im thinking there might have been old fuel in the tank and even mixing it with the new hadnt upped the octane rating enough to make it run smoothly. The fuel change has made a good bike even better.

 

[Bendy toy]

These bike will run on low octane fuel but they are not nice to use. I normally use Tesco 99 as the station is is close to home. I have a Power Commander set for open exhaust so the bike is stunning on 99. Put in the baffles and it will run slightly rich causing a cough at low speeds. Run it on 97 with open cans and its clearly not as sharp as on 99, but with the baffles it coughs a lot less.

So my reply to anyone who says the knock sensor does nothing is "try telling that to my bike".

 

[Gordon T]

Yes I hear what you are saying. Im putting the poor running down to the poor quality fuel that was in the bike. Changing it transformed it like night and day. Been out today again on it and cant fault it. Only slight niggle is that it runs a bit loud. Certainly a bit louder than I can remember or Im just getting a bit too sensitive!

My next little project is to aquire an AF-XIED double unit and posssibly knock the cat out from the end of the headers. This should liven it up a bit more and along with an exhaust valve removal tube fitted may make it a bit too loud to be sensible. G.

 

[Bendy toy]

Rather than knock the cat out you will do a lot better with proper headers. Used prices are not bad especially if you get a set that have heat tarnished. They clean up fine but will soon tarnish again.

 

[comberjohn]

Highly recommend the AF-XiED units. I've done around 4000 miles on them now and still can't believe it's the same engine as before. The developer, Roger, has measured that that they also make changes to the open loop part of the fueling over time and I find that it just pulls like a train from just over 2k rpm.
I've a 2010 TC with just over 30k miles on it. The TC is pretty loud as standard, hence the flappy valve. Reported to be louder than a standard SC.
I've been down the road of flappy valve removal, de cat standard headers and ending up with a full sport system.
Lasted a couple of days. Couldn't stick the racket over any distance.
Now I have a standard TC system back on, complete with flappy valve and for me it's just perfect. Quiet over long distance with a bit of a snarl for overtaking.
Power increase with the sport system might have been up slightly at higher revs, although I think it affected the lower range.
Not convinced it's worth it, although I'm sure there's plenty who will disagree.
Get the AF-XIED units first and see how you go. They're the only thing really worth having and if you decide to go down the middle aged hooligan route, at least they'll compensate for the changes.

 

[younger06]

We can only get the 95ron stuff here in The Emerald Isle......I started to go down the octane booster road a while ago but it's a pain and not an exact science!!!


I must take a spin up to Newry with fairly empty tanks just to try a tankful of 99ron.

 

[Bendy toy]

Check out what David Vizard has to say about octane booster on You Tube. He delivers a long lecture on the BMC A-Series engine, but the content (valves, porting, gas flows, fuels, ignition, etc) is the same as it ever was.

https://www.youtube.com/watch?v=ow5cGV7bXCw&list=PLebi5oqwVqUtyW8dKxt1Fz2hRr9_swG89

 

[Roger 04 RT]

Yes I hear what you are saying. Im putting the poor running down to the poor quality fuel that was in the bike. Changing it transformed it like night and day. Been out today again on it and cant fault it. Only slight niggle is that it runs a bit loud. Certainly a bit louder than I can remember or Im just getting a bit too sensitive!

My next little project is to aquire an AF-XIED double unit and posssibly knock the cat out from the end of the headers. This should liven it up a bit more and along with an exhaust valve removal tube fitted may make it a bit too loud to be sensible. G.

Gordon, A thought: try the AF-XIED first, then make the other changes one at a time.

 

[younger06]

Check out what David Vizard has to say about octane booster on You Tube. He delivers a long lecture on the BMC A-Series engine, but the content (valves, porting, gas flows, fuels, ignition, etc) is the same as it ever was.

https://www.youtube.com/watch?v=ow5cGV7bXCw&list=PLebi5oqwVqUtyW8dKxt1Fz2hRr9_swG89

Bendy, I tried but I couldn't the part about Octane Booster!!! Good or Bad ???

 

[Betty Swollocks]

We can only get the 95ron stuff here in The Emerald Isle......I started to go down the octane booster road a while ago but it's a pain and not an exact science!!!


I must take a spin up to Newry with fairly empty tanks just to try a tankful of 99ron.

Don't be in a rush to Newry... Tesco Momentum 99RON not available in Northern
Ireland. Best you can get is 97RON and its only about 20% of garages sell that.

I tried this with octane booster but no longer use the booster after having to replace both lambda probes....

 

[younger06]

Don't be in a rush to Newry... Tesco Momentum 99RON not available in Northern
Ireland. Best you can get is 97RON and its only about 20% of garages sell that.

I tried this with octane booster but no longer use the booster after having to replace both lambda probes....

Cheers..... you probably saved my wallet getting dragged into Crossans while I was up there!!

Sent using hocus pocus........... boo!

 

[Gordon T]

Gordon, A thought: try the AF-XIED first, then make the other changes one at a time.

Hi Roger. Whats your thinking on doing it this way and not all at once. Could it be that I may not need the cat removed?

 

[Roger 04 RT]

That's part of the idea. By adding the xied first you'll have a good baseline for how the bike runs at its best. Then as you try each other change you can evaluate how much improvement you get. Whereas if you change everything at once, if you don't get the results you were hoping, it will be difficult to tell why.

 

[comberjohn]

+1 on what Roger has said. Been there, done that.
The AF-XIED is the best single mod you'll make, even if you decide not to go any further down the 'performance' road.
If you've shelled out hundreds of pounds on a sports system, you'll find it difficult to admit that it's noisier but increase in performance is small.
Get it running right with the AF-XIED units first, then any changes in exhaust will be more obvious.
Most people, me included, do it ass about face.

 

[Mr Bean]

The AF-XIED is the best single mod you'll make, even if you decide not to go any further down the 'performance' road.

Didn't you recently pick Bendy up on commenting about something he had no experience of? Yet you are stating as fact (not your opinion) that the AF-XIED is the best single mod, yet you haven't tried a Hill Top remap.

If fact I think your comment was that his words had "no validity"

Strange..

 

[comberjohn]

Soo sorry.
Should have said in my experience, it's the best single mod you can make.
Should be flattered that someone remembers what I actually said.
Although, being objective about it, I still believe it's the best mod you can make.
Don't need a dyno to set it up, don't need to travel to get it done, easily fitted and removed to resell when getting rid of that 'keeper'. Wave bye bye to that £350 with your remap.
Is it better in terms of power and flexibility?
Don't know, same as everyone else. But I honestly doubt that there's unlikely to be any noticeable advantage in performance with a remap over AF-XIED.
There's obviously a limit on how much of a power increase is available by changing fuelling.
Maybe it's not as good as an AF-XIED!! That's me going to GS Hell.

 

[younger06]

Oh nooooooooooo......not another remap versus the world thread.



Somebody close it...............close it now!!

 

[younger06]

Let's have a chat about different octane values instead 99 vs 98 vs 97 vs (my only option) 95

 

[Bendy toy]

Bendy, I tried but I couldn't the part about Octane Booster!!! Good or Bad ???

He talks about finding the correct octane values from about 1 hour into the lecture. But the A-Series engines under discussion have no knock sensors. He mixes fuel to have just the right octane and explains blending values.

An engine with knock sensors will automatically adjust the spark timing to suit the fuel. I know very little about the GS-911 but if you can read the spark advance setting with the engine in use you will be able to work out the best fuels or additives to use. Someone who knows the GS-911 might know if that's a usable feature.

 

[younger06]

He talks about finding the correct octane values from about 1 hour into the lecture. But the A-Series engines under discussion have no knock sensors.

An engine with knock sensors will automatically adjust the spark timing to suit the fuel. I know very little about the GS-911 but if you can read the spark advance setting with the engine in use you will be able to work out the best fuels to use. Someone who knows the GS-911 might know if that's a usable feature.

Cheers.
I just feel a little hard done by that I can't get better than 95ron in my little country.

Sent using hocus pocus........... boo!