OH, Goody - a broken valve

[rmalc.wright@btopenworld.com]

Just what I wanted for Christmas.
Big Bang - no power and a one lung bag of spanners. The nice man takes it back to the dealership - it's less than three months since I bought it - and today he tells me it dropped a valve.
Aren't I glad I bought a BMW R1200GS with only 23,000 miles on the clock?
I have a BMW 730, 1991, just over 202,000 miles - just nicely run-in. I had a K1 and threw that around the highways and byways for 49,000 miles and it still did a genuine 150mph.
So, I thought a BMW boxer? been around for 80 years, must have got it sorted by now. Should be bullet-proof.
If the pump controller doesn't pack up the valve heads will snap off.
Before I get back on it, is there anything else I should know? Do the handlebars come off when you corner? Does the back wheel go faster than the front? Do they need a harder grade of cheese for the engine parts?
As far as I'm concerned, if it has BMW on the label I should be able to run over it witha steam roller and break the roller. Anything less just isn't good enough for the extra money.

 

[(RIP) Proff]

Should have bought one of the proven models

You know, the 1100 or 1150 versions
and saved some pennies to spend on Bling and Touring foreign parts without wondering if the AA have patrols in Morocco..

By the way.
Welcome to the site
You're going to like it here I can tell

 

[patzx12]

My 05 dropped a RH valve on a track day. A bit of a joke really there was plenty of highly abused old 80's and early 90,s Jap bikes and non of them came back in on a trailer. I often wonder how the Boxer cup bikes got on reliability wise.
Still a great bike but not a redline kind of machine, pity it is great fun on a track day.

 

[longdog]

They don't make 'em like they used to..........

 

[Mav]

My 05 dropped a RH valve on a track day. A bit of a joke really there was plenty of highly abused old 80's and early 90,s Jap bikes and non of them came back in on a trailer. I often wonder how the Boxer cup bikes got on reliability wise.
Still a great bike but not a redline kind of machine, pity it is great fun on a track day.

Is it redlining that can lead to dropping a valve??

 

[rmalc.wright@btopenworld.com]

wanted one of them, but wanted ABS. Had it on the K1 and it saved my neck. Like a parachute, you look silly wearing one until you need it. By the way, the nice man says he's replacing all four valves with upgraded extra mature cheese ones.

 

[LiquidLAN]

Don't worry, I've been assured, everytime I've been back the the dealer, that these problems only ever happen once, the problem never happens with the replacement parts.

 

[patzx12]

Is it redlining that can lead to dropping a valve??

Not sure Mav, I have never dropped a valve on any other bike, My 05 bike was thrashed like a jap sports bike for 8000kl and I broke a gearbox (the shaft came out) and dropped a valve. Its fixed now and I will track day it this year and see how I go. I am more gentle with my 04 GS and my GSA.
I love BMW's owning 4 of them and will continue to ride BM's until the Japanese produce a comparable bike. I just put up with the reliability thing, I am a bit of an expert on fixing GS'es now.
Doing my 06 GSA FD now see my post, it's rediculus a shaft drive failing in 17000 miles.

 

[Fanum]

OH, Goody - a broken valve

Just as a matter of interest, were you in the habit of leaving the bike on the side stand?

 

[longdog]

Is it redlining that can lead to dropping a valve??

Not necessarily........ It may be a sloppy or missed gearchange.

If the engine is under load and within the maximum rev limit, then there should be no problem. Bear in mind, the redline is not necessarily the safe maximum revs for the machine, as manufacturers will test an engine in excess of the redline or rev-limiter then set a "safe" maximum.

When a gearchange is missed, the engine is usually under load at that point and without that loading will continue to spin above the maximum safe limit. For example, you are on a push bike, pedaling for your life, when you change down a gear instead of up. The pedals fairly fly around and you go nowhere, but the action is uncontrolled.

Of course, it could be a faulty batch of valves! (That was for all the fast boys with perfect gearchange technique).

 

[Gipsy]

Not necessarily........ It may be a sloppy or missed gearchange.

If the engine is under load and within the maximum rev limit, then there should be no problem. Bear in mind, the redline is not necessarily the safe maximum revs for the machine, as manufacturers will test an engine in excess of the redline or rev-limiter then set a "safe" maximum.

When a gearchange is missed, the engine is usually under load at that point and without that loading will continue to spin above the maximum safe limit. For example, you are on a push bike, pedaling for your life, when you change down a gear instead of up. The pedals fairly fly around and you go nowhere, but the action is uncontrolled.

Of course, it could be a faulty batch of valves! (That was for all the fast boys with perfect gearchange technique).

Good post. Redlining when not under load is a common cause of dropped valves. If you are in the habit of over revving on the downchange it may cause problems, as can over enthusiastic revving of the bike while at a standstill.

 

[rmalc.wright@btopenworld.com]

Just as a matter of interest, were you in the habit of leaving the bike on the side stand?

Not in the garage, I bought one of those push-in stands, saves space and hassle. But, I cannot accept that leaving it on a side stand is a cause. If a manufacturer fits a side stand, then it better be usable, otherwise that is an enormous design fault and there is no warranty limit on design faults and we all get new bikes free.. Anyway, whenever I start any vehicle, I let it run up for a few seconds before doing anything - except hire cars and my GSXR - but then I expect to throw that down the road long before I break the engine.
On the over-revving thing, this too should be a no-go. the limiter will back off the fuel and then cut ignition way before you get to the red-line. Should. Again, if it doesn't, that is a design fault - a rev limiter that doesn't protect from over-revving? as much use as a chocolate teapot.

 

[Fanum]

But, I cannot accept that leaving it on a side stand is a cause.

You may not accept it or like it, but it does seem to be the most likely contributary factor.

The side yours went on....it was the opposite side from the side stand wasn't it?

It does seem to be a design fault and oil starvation has been blamed in a lot of cases- yours isn't an isoltaed one by any means

BTW It's not acceptable I agree...you absolutely SHOULD be able to leave it on the side stand without it causing this sort of problem, I agree.




Go on, let us know- was it the 'high' side valves that went??

 

[rmalc.wright@btopenworld.com]

Don't worry, I've been assured, everytime I've been back the the dealer, that these problems only ever happen once, the problem never happens with the replacement parts.

Umm, how many times have you been back to the dealer?
does he think of you as a two wheeled homing pigeon, bringing him broken bikes and your credit card?

 

[cherokee]

Just what I wanted for Christmas.
Big Bang - no power and a one lung bag of spanners. The nice man takes it back to the dealership - it's less than three months since I bought it - and today he tells me it dropped a valve.
Aren't I glad I bought a BMW R1200GS with only 23,000 miles on the clock?
I have a BMW 730, 1991, just over 202,000 miles - just nicely run-in. I had a K1 and threw that around the highways and byways for 49,000 miles and it still did a genuine 150mph.
So, I thought a BMW boxer? been around for 80 years, must have got it sorted by now. Should be bullet-proof.
If the pump controller doesn't pack up the valve heads will snap off.
Before I get back on it, is there anything else I should know? Do the handlebars come off when you corner? Does the back wheel go faster than the front? Do they need a harder grade of cheese for the engine parts?
As far as I'm concerned, if it has BMW on the label I should be able to run over it witha steam roller and break the roller. Anything less just isn't good enough for the extra money.

Think the final drives made of chocolate,so hey look on the bright side you wont starve while your waiting for the AA

 

[rmalc.wright@btopenworld.com]

You may not accept it or like it, but it does seem to be the most likely contributary factor.

The side yours went on....it was the opposite side from the side stand wasn't it?

It does seem to be a design fault and oil starvation has been blamed in a lot of cases- yours isn't an isoltaed one by any means

BTW It's not acceptable I agree...you absolutely SHOULD be able to leave it on the side stand without it causing this sort of problem, I agree.




Go on, let us know- was it the 'high' side valves that went??

I haven't seen the bits, but since the RH exhaust was cold by the time I limped home, I guess that it was. I suppose I have to agree with you. Upon reflection, I have never been happy about starting a bike on a side stand and I think my usual practice has been to get on and stand them up before starting them. But since this is a "Pre-owned" machine, I have no idea what was done to it.

Now, think about this. If you over rev (and I accept you can on the downchange or a really crap shift) then the problem is with the valve closing. on a non-desmo engine, at high revs, the valve may be clear of the cam and slams shut under spring alone with a nice big bang. which means the seats could be shot?

 

[Steptoe]

Not the first post about 1200 models dropping valves. 1200RT's seem to do it a bit more regular than the GS.

 

[Timolgra]

Now, think about this. If you over rev (and I accept you can on the downchange or a really crap shift) then the problem is with the valve closing. on a non-desmo engine, at high revs, the valve may be clear of the cam and slams shut under spring alone with a nice big bang. which means the seats could be shot?

You could be on the right track there, in the quest for more performance from an adventure bike the cams may have a more aggresive lift and closure profile whilst valve material remains the same leading to a theoretic outcome similar to your suggestion.

 

[Pukmeister]

I bet it was an exhaust valve rather than an inlet. I suspect these engines run so lean for emissions compliance that there may be a risk of localised heating of the exhaust valve head and stem when riding 'briskly'. Thats just a guess though and not based on any data or personal experience of this particular type of failure.

Any of the forum members with dyno time have any graphs showing the air/fuel ratios before power commanders etc are fitted ? Any notable lean areas in the rev range ?

 

[John Armstrong]

Any of the forum members with dyno time have any graphs showing the air/fuel ratios before power commanders etc are fitted ? Any notable lean areas in the rev range ?

From memory, the 1200GS before the 08 bikes took off fairly steeply after 5000 revs on the power and there was a bit of a hole just before that on the torque graph. Bet they measure noise etc just before 5k revs.