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Re: Puff of Smoke
Posted: Sun Jun 05, 2022 10:51 am
by Gavj
@Sakm, did you notice any difference with the valve removed / disabled ( I assume its still there just pernamenty open), allegidly its purpose is to increase torque at low revs... not that a 1250cc twin is likely to lack in torque....
Re: Puff of Smoke
Posted: Sun Jun 05, 2022 12:44 pm
by Stu
I can't tell a difference at all
Re: Puff of Smoke
Posted: Sun Jun 05, 2022 4:15 pm
by B787MECH
sakm wrote:
The same one that will cause the problem again and again!
Best to disconnect it and remove the motor and fit an eliminator!
I had issues with mine and tried twice to stop it seizing then just spent £40 and removed everything I could
https://www.healtech-electronics.com/products/ese
I agree that if the valve seizes it’s best to disconnect it and fit an eliminator. I haven’t had any problems with mine in the six years from new and 27,000 miles. I put it down to only ever using good quality petrol eg Shell V Power which gives a cleaner burn and has lubricity and cleaning additives. I never use cheap supermarket fuel. I believe the fuel in Germany is higher spec than most UK stuff which might explain things. I always listen for the valve cycling when the ignition is switched on, and check it whenever the silencer is removed.
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Re: Puff of Smoke
Posted: Sun Jun 05, 2022 4:19 pm
by B787MECH
sakm wrote:
I can't tell a difference at all
I understand it’s there to reduce the noise at low revs i.e in town?
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Re: Puff of Smoke
Posted: Sun Jun 05, 2022 4:23 pm
by Stu
B787MECH wrote:
I agree that if the valve seizes it’s best to disconnect it and fit an eliminator. I haven’t had any problems with mine in the six years from new and 27,000 miles. I put it down to only ever using good quality petrol eg Shell V Power which gives a cleaner burn and has lubricity and cleaning additives. I never use cheap supermarket fuel. I believe the fuel in Germany is higher spec than most UK stuff which might explain things. I always listen for the valve cycling when the ignition is switched on, and check it whenever the silencer is removed.
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Sorry to say but there is nothing in the fuel that will help lubricate the valve after it has being burnt if there was it would destroy the catalytic converter
Its a hard thing to keep lubricated as the heat just burns everything off and once is starts to seize it will just happen again and again
Re: Puff of Smoke
Posted: Sun Jun 05, 2022 4:26 pm
by exportman
B787MECH wrote:
I understand it’s there to reduce the noise at low revs i.e in town?
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Yep mine has been stuck open for the last 5K+ no problems with performance just a little louder at low revs.
Re: Puff of Smoke
Posted: Sun Jun 05, 2022 5:15 pm
by Gavj
I know they won't , but it would be good if BMW gave me the old headers so that I could have a poke about to see if it could be modified to allow some periodic lubrication... sounds as if it needs some graphite based anti sieze.....re applied now & again.
Well the new one should last for a bit, probaby untill the warranty runs out, then it will be a delete kit when it goes again.
Re: Puff of Smoke
Posted: Sun Jun 05, 2022 5:57 pm
by B787MECH
sakm wrote:
Sorry to say but there is nothing in the fuel that will help lubricate the valve after it has being burnt if there was it would destroy the catalytic converter
Its a hard thing to keep lubricated as the heat just burns everything off and once is starts to seize it will just happen again and again
I think Shell know a bit about producing a fuel that burns cleanly. It has a detergent in it and a lubricity agent. Cheap fuel leaves a gunk residue which gathers around the butterfly hinge and eventually impedes it functioning correctly. Next time you have the silencer off is the area around the valve grey or black. Like I say, I’ve had no problems with mine.
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Re: Puff of Smoke
Posted: Sun Jun 05, 2022 6:00 pm
by Stu
Gavj wrote:
I know they won't , but it would be good if BMW gave me the old headers so that I could have a poke about to see if it could be modified to allow some periodic lubrication... sounds as if it needs some graphite based anti sieze.....re applied now & again.
Well the new one should last for a bit, probaby untill the warranty runs out, then it will be a delete kit when it goes again.
I have had my headers off and had a good look and also soaked the valve in diesel and also dissolved some copper grease in diesel in an attept to get some of the copper particles in to the mechanism!
It worked and was nice and free but soon seized up again
A lot of other people have tried the graphite method and it just failed again
Re: Puff of Smoke
Posted: Sun Jun 05, 2022 6:03 pm
by Stu
B787MECH wrote:
I think Shell know a bit about producing a fuel that burns cleanly. It has a detergent in it and a lubricity agent. Cheap fuel leaves a gunk residue which gathers around the butterfly hinge and eventually impedes it functioning correctly. Next time you have the silencer off is the area around the valve grey or black. Like I say, I’ve had no problems with mine.
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I have had the headers off and they was clean as a whistle!
The stuff you are talking about it to lubricate before it burns and has cleaning agents in to clean the carbon off before it has burnt off!
I only use BP ultimate or Shell here no cheap fuels as they are crap and stay well away from supermarket fuel! that stuff is just the work of the devil
Re: Puff of Smoke
Posted: Sun Jun 05, 2022 7:27 pm
by Levisp
B787MECH wrote:
I think Shell know a bit about producing a fuel that burns cleanly. It has a detergent in it and a lubricity agent. Cheap fuel leaves a gunk residue which gathers around the butterfly hinge and eventually impedes it functioning correctly. Next time you have the silencer off is the area around the valve grey or black. Like I say, I’ve had no problems with mine.
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I'm not sure its as simple as that because I use the cheapest supermarket fuel I can get and after 52K miles I have had virtually no problems. I have only had to free up valve once in nearly 8 years of use. Interestingly that was after the bike had little use due to Covid restrictions. Now I am back to riding every week I have had no further issues summer or winter. Maybe I have just been lucky.
Re: Puff of Smoke
Posted: Fri Jun 10, 2022 11:33 am
by Gavj
Got the bike back yesterday, brand new headers, valve. Driver unloaded it, I started it, no engine light....... for 6 seconds, and it's back on again... ho hum....Bike on its way back to dealer this morning..
Looking forward to the customer survey..... ???
Re: Puff of Smoke
Posted: Sun Jun 12, 2022 2:52 pm
by Gavj
Hopefuly thats it this time, fair play to BMW they took the bike away on the Thursday and returned it on Saturday, turned out to be a loose wire.... Service guy said that the self test routine for the exhaust valve now only happens every 30th start?
Still no reason for the smoke that one time......
Re: Puff of Smoke
Posted: Sun Jun 12, 2022 7:10 pm
by Panman40
Gavj wrote:
Got the bike back yesterday, brand new headers, valve. Driver unloaded it, I started it, no engine light....... for 6 seconds, and it's back on again... ho hum....Bike on its way back to dealer this morning..
Looking forward to the customer survey..... ???
Christ. I hope you get this sorted.
Re: Puff of Smoke
Posted: Tue Jul 12, 2022 4:05 pm
by Doctor T
My Mum's neighbours 2021 Rt gives a bit of smoke on start up if he leaves it parked up on the side stand after a week or so. From what ive gathered from a tec is that BMW had to reduce the exhaust noise to get through the Euro noise limits, hence a flap that is closed/partly closed at lower revs. Most high end sports cars use the same system. Even Bently and Rolls Royce have a similar system to pass the noise limits.
Eliminating the valve will only make the exhaust tone a little deeper at low revs and does not affect the bike running or fuel at all.