Dodging exhaust flap bullets!!

[Excellence]

Dodging exhaust flap bullets!!
So... it appears now that not all private sellers of BMW motorcycles are necessarily truthful. Having cleared every fault and cycled everything in sight using the GS-911 the '21 RT was running beautifully. Smooth up shifts; a screen clear of everything except what I wanted to see and then smack!! We stopped for a sausage roll and a coffee not long after we started our journey through the Cairngorms on Monday last and on restart to continue the journey an engine warning light shows itself on the TFT.
The bike becomes slightly louder and had become a bit more spritely.
The warning lamp remains lit for the whole of the remaining 200 mile journey. I knew I'd cleared all faults and done the business with the 911 and so I became suspicious of something fundamentally wrong being the culprit - the end of the warranty period was looming too!
Tuesday morning I call BMW because the warranty runs out on Monday next (6/3) and to my relief they want the bike in on Wednesday morning to fix whatever is wrong. I deliver the bike through pouring rain and hand it over. That was 08:15 and at 15:15 I receive a text telling me the bike is ready. I go back to be told the exhaust flap system had failed and they say that "No", contrary to what I was led to understand at purchase, it hadn't already been replaced for the previous owner - cheers Simon!
It seems the dealership had a replacement exhaust system on the shelf and without any prompting at all they decided to replace it - nae fuss! I now have a ridiculously shiny exhaust system that for the time being is working just fine.
I'm grateful to the Aberdeen dealership for their prompt attention and for fixing the bike so quickly without any discussion being necessary. Has to be said - they still won't be doing any servicing but as to the big stuff needing to be done - we'll see.
This has led me to wonder what's causing these exhaust flap problems.
During a recent-ish advanced training exercise through the highlands I was constantly being told over the radio to get it into the power band - (this was on my ST1300 not the RT).
When I picked up the RT after it had been fixed, the service guy told me that the dealership had been told by BMW that carbon deposits seemed to be among the prime suspects for causing the problems.
So... I'm wondering whether the Police R1250RTs are suffering the exhaust flap problem and if not, could this be because they tend to use their machines at higher engine revs for more of the time to maintain using them 'in the power band' - more heat; more efficient combustion; higher exhaust flows; less carbon in the system!
Do those who do experience the problem tend to allow the engine to 'lug' or just chug along peacefully or upshift perhaps a wee bit early so allowing the creation of carbon in the exhaust flow as they accelerate at a less than optimum power setting?
I've decided now that for as long as it's reasonable/possible I will use the machine's engine in exactly the way I was instructed to on the ST. Maintain the power band and use it as close to 50% of available revs as I can while manoeuvring the bike.
We'll see how I get on with that strategy. We rode the machine out for a ride to coffee and rolls today over about 60 miles and consumption is still up at 60mpg so it's not suffering too much that way. The roads were in good order and twisty but still quick.

[Stu]

its irrelevant how you ride it the exhaust flap will still seize up!

The trouble is you can't get any lube in it and get it to stay due to the heat generated it just burns it off

I took my exhaust off the other day and fitted my blackwidow downpipes and the flap was stuck solid! although it has been disconnected for over a year now with a healtech servo eliminator fitted

[Excellence]

I've already bought the ESE for install should the flap fail again and BMW aren't then quite so understanding as they were last week.
Was it really such a straightforward install - no canbus issues at all?
Once fitted did your bike seem much different at all?

[Panman40]

Dodging exhaust flap bullets!!
So... it appears now that not all private sellers of BMW motorcycles are necessarily truthful. Having cleared every fault and cycled everything in sight using the GS-911 the '21 RT was running beautifully. Smooth up shifts; a screen clear of everything except what I wanted to see and then smack!! We stopped for a sausage roll and a coffee not long after we started our journey through the Cairngorms on Monday last and on restart to continue the journey an engine warning light shows itself on the TFT.
The bike becomes slightly louder and had become a bit more spritely.
The warning lamp remains lit for the whole of the remaining 200 mile journey. I knew I'd cleared all faults and done the business with the 911 and so I became suspicious of something fundamentally wrong being the culprit - the end of the warranty period was looming too!
Tuesday morning I call BMW because the warranty runs out on Monday next (6/3) and to my relief they want the bike in on Wednesday morning to fix whatever is wrong. I deliver the bike through pouring rain and hand it over. That was 08:15 and at 15:15 I receive a text telling me the bike is ready. I go back to be told the exhaust flap system had failed and they say that "No", contrary to what I was led to understand at purchase, it hadn't already been replaced for the previous owner - cheers Simon!
It seems the dealership had a replacement exhaust system on the shelf and without any prompting at all they decided to replace it - nae fuss! I now have a ridiculously shiny exhaust system that for the time being is working just fine.
I'm grateful to the Aberdeen dealership for their prompt attention and for fixing the bike so quickly without any discussion being necessary. Has to be said - they still won't be doing any servicing but as to the big stuff needing to be done - we'll see.
This has led me to wonder what's causing these exhaust flap problems.
During a recent-ish advanced training exercise through the highlands I was constantly being told over the radio to get it into the power band - (this was on my ST1300 not the RT).
When I picked up the RT after it had been fixed, the service guy told me that the dealership had been told by BMW that carbon deposits seemed to be among the prime suspects for causing the problems.
So... I'm wondering whether the Police R1250RTs are suffering the exhaust flap problem and if not, could this be because they tend to use their machines at higher engine revs for more of the time to maintain using them 'in the power band' - more heat; more efficient combustion; higher exhaust flows; less carbon in the system!
Do those who do experience the problem tend to allow the engine to 'lug' or just chug along peacefully or upshift perhaps a wee bit early so allowing the creation of carbon in the exhaust flow as they accelerate at a less than optimum power setting?
I've decided now that for as long as it's reasonable/possible I will use the machine's engine in exactly the way I was instructed to on the ST. Maintain the power band and use it as close to 50% of available revs as I can while manoeuvring the bike.
We'll see how I get on with that strategy. We rode the machine out for a ride to coffee and rolls today over about 60 miles and consumption is still up at 60mpg so it's not suffering too much that way. The roads were in good order and twisty but still quick.

That’s rather underhand of the previous owner . That’s great service from your dealer i would stick with them for anything you need going forward!.
You must be chuffed with that nice shiny set of headers . My 19 1250 was used year round and suffered corrosion as you know before I had it so I’m surprised the flap seems loose enough unless they were replaced, I suppose I could find that out but I did ask the first dealer of any issues before I bought it.
Now you’re almost out of warranty are you going to extend it ?, I did but it’s up again in July I think and had no intention of going for a fourth years policy as I want to service the thing myself, I may have to have one more service when I hit 12,000 mls though otherwise it’ll void what’s left.
As for riding in the midrange all the time, nope I won’t be doing that, I know some boxer twin owners do but I’m not one of them. If I’m out on a gentle ride with my wife I just ride casually but never lugging the motor obviously.
Talking of the exhaust flap servo eliminator, is this fine legally ?, insurance wise and for mot etc ?.

[David.]

This is an example of part of a dyno run chart for an RT, below ~3000 rpm, the engine is running lean.

[David.]

Now you’re almost out of warranty are you going to extend it. I did but it’s up again in July I think and had no intention of going for a fourth years policy as I want to service the thing myself. I may have to have one more service when I hit 12,000 miles though otherwise it’ll void what’s left.

What date was the bike last serviced and what is the current mileage.

[Panman40]

This is an example of part of a dyno run chart for an RT, until above ~3000 rpm, the engine is running lean.

I’ll dig out my own service log later and the dealer service I had and post up. The issue I initially had was taking it in for a 12k service at 10k, they supposedly checked the valve clearances and changed brake fluids, I’ve done oil and filter, plugs plus air filter myself and final drive service, new rear disc and pads etc. The dealer is adamant they will have to do a valve clearance at 12k especially for warranty reasons.
As I’ve ordered £350 worth of tools which are not arriving until April I’m hoping to do the whole thing myself and let the warranty go!.

[David.]

I’ll dig out my own service log later and the dealer service I had and post up. The dealer is adamant they will have to do a valve clearance at 12k especially for warranty reasons.

The reason for asking is that there is some flexibility with the warranty. You are allowed to go 1 month and/or 1,000 miles past the due date or mileage. The other thing is that the warranty can be cancelled and part refunded but when I last asked, there was a 25GBP admin fee too.

[Stu]

I've already bought the ESE for install should the flap fail again and BMW aren't then quite so understanding as they were last week.
Was it really such a straightforward install - no canbus issues at all?
Once fitted did your bike seem much different at all?

There is a simple answer here

fit the ESE and see how it feels to you

For me I could not see a notable difference

as for fitting its was pretty straight forward and no you don't get any issues at all its designed to mimic the motor so the bike thinks its working fine

Personally I would fit and forget

[Stu]

The reason for asking is that there is some flexibility with the warranty. You are allowed to go 1 month and/or 1,000 miles past the due date or mileage. The other thing is that the warranty can be cancelled and part refunded but when I last asked, there was a 25GBP admin fee too.

If you are just thinking of cover for the exhaust the extended warranty and the 2 year approved used warranty doesn't cover the exhaust

[Excellence]

No, I won't extend the warranty because although I was pleased with them and the job they did last week, I do tend to do my own anyway.
I'm slightly puzzled by the dyno chart.
My understanding was that the ideal or stoich point AFR for petrol was around 14.7/1 rather than what the chart is showing much lower at <13.5/1. BMW engines being highly engineered may operate toward the upper end of their pressure capabilities and so they probably drop their spec AFR to avoid nasty events in the cylinders at ratios at or close to stoich. In any event the rev range I'd be looking at would be around 3400-3500 maybe to 4000 occasionally and while the chart seems to show a richer mixture at around 13/1 as a mean ratio the engine would remain fairly steadily somewhere in their preferred range (accepting it as shown) all the way up to peak power at about 7500 so it should be good anyway.
Healtech do state the ESE should be used off road only and so the point about potential insurance issues may be entirely valid. However one could argue that it's safer to have a bike on the motorway at speed when it cannot suffer some catastrophic failure should the flap fail catastrophically than one that could. The issue of a lack of lubrication is the worst of all of it. Personally I don't believe that this is beyond the wit to solve. By design, the bearings/bushes could quite easily (in engineering terms) be removed from the exhaust stream and so proper lubes/serviceability could be achieved without compromising an effective, if not perfect, gas seal for the exhaust. Could manufacturing cost alone, be a factor in this issue.

[Excellence]

There is a simple answer here

fit the ESE and see how it feels to you

For me I could not see a notable difference

as for fitting its was pretty straight forward and no you don't get any issues at all its designed to mimic the motor so the bike thinks its working fine

Personally I would fit and forget

You may be right. If you think about it too much it takes the fun out of riding the darned things anyway! when it fails again I'll fit it. Did you actually remove the servo or just make sure the flap was inline/open when you put the ESE on. I think I'd want to remove the cables and the sevrvo.

[Stu]

at anything over about 2k the flap is wide open

A lot of people say that the flap is there for noise emissions and that may well be one reason but they are also designed to give a little back pressure to give you a little more low down torque. Think back to the days of the Yamaha EXUP valve

as for the A/F ratio this is purely for emissions reasons to meet the ever stringent EURO 4,5 & 6 standards

Euro 6 engines run very lean and very hot by comparison and even as low as 12.5 A/F ratios

[Stu]

You may be right. If you think about it too much it takes the fun out of riding the darned things anyway! when it fails again I'll fit it. Did you actually remove the servo or just make sure the flap was inline/open when you put the ESE on. I think I'd want to remove the cables and the sevrvo.

There is a spring on the flap mechanism thats supposed to open the flap if it fails and this is pretty strong and holds the flap in the open position

I removed the motor and the cables ................. and now the exhaust

My plan is to get the bike remapped anyway due to the lean running to give it more midrange torque and overall they run better when done

[Stu]

This video shows how little they move and if you have the volume on you will notice that at very low RPM/idle its at its fully "closed" position it only closes around a quarter of its full movement

and anything above idle its open