So Do Ya think Maybe possibly ........

[Andy Davies]

Maybe using one of the accelerator modules (see 1200 section) may help by lowering the AFR, dropping the combustion temperature and thus reduce the potential for burning the valves

Andy

 

[DrFarkoff]

Maybe using one of the accelerator modules (see 1200 section) may help by lowering the AFR, dropping the combustion temperature and thus reduce the potential for burning the valves

Andy

Andy appreciate the thought BUT why should anyone have to buy a part like that to make sure that thier bike isn't gonna schit itself

If that vein of thought is followed then BMW R1200 GS are not fit for thier intended purpose

Also it would be interesting to collate data from everyone who had a failure and a percentage of those who haven;t and see if there is a correlation in the circumstances of failure!

 

[wully]

I don't see how that could do it, but who the hell knows.

I though about the side stand thing as it's the only thing I can think of that's different from the RH and LH sides- anyone think of anything else??

 

[jpooch00]

I got to thinking about the new dual-cam engines, and I'm wondering if with the slightly heaver valves combined with the increased redline and the stronger springs that are probably going to be necessary to control the valves, will all that stress the stem joint even more and make this issue even worse?

 

[MattW]

I got to thinking about the new dual-cam engines, and I'm wondering if with the slightly heaver valves combined with the increased redline and the stronger springs that are probably going to be necessary to control the valves, will all that stress the stem joint even more and make this issue even worse?

I'd worry more about the skew ground cams and nightmare valve clearance procedure...

 

[chad]

I'd worry more about the skew ground cams and nightmare valve clearance procedure...

yup service costs up and home service at your peril unless your super confident

 

[jpooch00]

I'd worry more about the skew ground cams and nightmare valve clearance procedure...

Yeah, that too!

 

[jpooch00]

Andy appreciate the thought BUT why should anyone have to buy a part like that to make sure that thier bike isn't gonna schit itself

If that vein of thought is followed then BMW R1200 GS are not fit for thier intended purpose

Also it would be interesting to collate data from everyone who had a failure and a percentage of those who haven;t and see if there is a correlation in the circumstances of failure!

I agree 100% with that statement, but just look at what a lot of the Harley owners do to make their new bikes run cool enough to ride comfortably and also have the power that a 96 CID engine should have.

Many spend several thousand dollars above what they pay for the bikes to get more than the 60 stock HP out of them and to keep them from trying to melt themselves (AND the rider AND the passenger).

If this one little part would actually fix the issue, and maybe it would, it might not be too bad in the long run.

 

[Andy Davies]

A few years ago i had one of the 'new' Bonnevilles. One of the first things I did was to remove the air injection system (I think I;ve still got it in the garage if anyone wants it). This dramatically reduced the header temperatures as could be seen by the lack of incandescence in the down tubes.

Emission control can be to the detriment of the hardware in many ways. I can recall in the early 70s when working in the experimental department at Jaguar in Coventry, the first XJ12s with catalytic converters used to set grass on fire if you parked on it, as I found out

Andy

 

[bumpy]

A few years ago i had one of the 'new' Bonnevilles. One of the first things I did was to remove the air injection system (I think I;ve still got it in the garage if anyone wants it). This dramatically reduced the header temperatures as could be seen by the lack of incandescence in the down tubes.
Andy

Yep me too

 

[james0133]

There is a Heads and Cylinder on eBay you might want to check out, though depending on the extente of the damage you might get away with just replacing the Valve Guide, Valve and Piston:

Did you have any modifications to the bike?

In terms of the heat build up changing the molecular structure of the valve, I would imagine this problem would be much worse in hot countrys.

Its a terrible thing to happen. I hope you get it sorted with out too much expense and hassle.

 

[OldCroc]

I though about the side stand thing as it's the only thing I can think of that's different from the RH and LH sides- anyone think of anything else??

RH cylinder is set back about 6cm more than the left?

 

[MattW]

RH cylinder is set back about 6cm more than the left?

The heads rely heavily on oil cooling - I'd go for cooling differences between the two heads...

 

[ktmmark]

When you order new valves, tell them you want the for the left cylinder that should sort it

 

[DrFarkoff]

Thought I'd give a ray of hope to those that have had the dreaded failure!

And I fitted an accelerator on this one and a recyclizer on another

Yeah maybe we shouldn't need them But By Feck It has smoothed things out a bit and hopefully the "less Lean" Burn will help the exhaust / head temperatures to be much cooler.

I decided on using and aftermarket doofer to increase the Fuel air ratios after reading Goosepilots post about his Bike pinging in the heat etc etc

Now this MOT'd last Saturday

 

[GSmonkey]

Do you have to carry an oily rag around with you at all times now ??

 

[DrFarkoff]

Do you have to carry an oily rag around with you at all times now ??

Nope My Mate Pete the Owner will

I was just gonna service it and give the cover a bloody good clean up and it did it while I was doing a run to warm the oil about half a mile from my house

I lost my faith in 1200s just then

But Like everything Time and patience and a Few shekels and they can be sorted

 

[ianran]

Okay, but then why only exhaust valves, and why mostly on RHS ?

Could it be were bike is on the side stand, started when lifted but oils not circulsting to this side as quickly?

 

[DrFarkoff]

Valves stems are not pressure fed So why would that matter Cams failing etc would be a different matter

After doing loads and loads of reading on the net etc My Vibe on it is heat, If the valve can't dissapate heat it gets hotter and hotter

The only consistant thing is the lean burn Lean Burn = Heat and lots of it original K1200 exhaust cans would lift the skin off your hand if you touched them after a long run

Also Think back to 2 strokes When do they usually sieze ???

At the end of the straight where the bike has been running at High rpm and usually on a very lean mixture = Lots of heat!

I gave up as Neither myself or pete have access to a Dyno and software for a remap so the accelerator/recyclizer is a cheap option that hopefully will be enough to allow the the engine to run at lower operating temps and keep valves where they should be

Could it be were bike is on the side stand, started when lifted but oils not circulsting to this side as quickly?

 

[elefantman]

This may be an unpopular thought which is unusual for me but anyway....dropped exhaust valves are caused by running a lean mix,popping from the exhaust on over run is caused by running a lean mix,all new bikes have to run lean to pass euro 3,when you alter the exhaust you get even leaner,an end can makes little difference,a decat and end can will,the best way to kill your engine,any engine,is half arsed home tuning and shitty supermarket fuel,the best thing you can do leave standard and run vpower,if you want more then fit a pcv and autotune before anything else,the acc mod will not stop you going bang,a pcv with a/t will always give you the right mix at sea level or in the alps,oh and two stokes go bang when you close the throttle because you also stop the oil getting in,always blip the thottle on down changes to squirt some lube in...