Balance Problems?

[Bydand]

Ever since my 12 GS was broken down to have its gearbox seals replaced it seems to go out of balance very quickly. Initially I thought it was just settling in again after all the cables etc had been upset but thats not been the case. It had its gearbox seals done around 10K then it was balanced again before its 12k service and its been balanced by the dealer and me since, its now done 14k and I've just had to do it again.

I'm just using vacuum guages to balance it up and adjusting the throttle cable tensions to get the vacuum lifting off ay the same time on both cylinders. I believe that I should be disabling something when I'm doing this but also believe that I need the dealers computer to do this, the dealer is about 160 miles away so you'll no doubt see why I don't pop in there every time the thing goes lumpy on me.

I'm getting really fed up with the bike as a result of it going out of balance so quickly....is anyone else suffering this?

 

[terayon]

You can only balance throttle bodies at 3000rpm and above, the lower rpm's get controlled by the stepper motor and that can only be done by a dealer.
Make sure all cables have 1 mm of free play and adjust the one that's opening up first(slacken) and not the one opening last (losing the free play). This is how the manual says to do it.

 

[Jaq]

Or......just drink more alcohol and the bike won't seem out of balance at all!!......

 

[birdseye]

Its not a matter of lift off - its a matter of balancing the air pressure in the throttle bodies at (say) 3000 rpm. What you are doing is likely to give variable results, influenced by the stepper motors.

In any case, is there a real problem with the running of the bike or are you being a bit of a "mechanical hypochondriac(?)". Its easy enough to be that - do it frequently myself. So unless you have a real balance problem (and remember it will never be as well balanced as an in line 4) then best thing is to put your guage in the back of the drawer and enjoy the bike.

P.S. Reading posts on this site makes you realise you have problems that you never even knew existed. Your bike is about to disintegrate. No BMW paint has ever been known to last more than 4k miles. All BMW gearbox shaft seals leak. And the BMW seat gives you piles (I cant spell hemarrhoids) and ruins your sex life etc etc

 

[Bydand]

Birdseye, Thanks, I'll have a go as you suggest. I may be getting a little sensitive to the bike but, it used to run beautifully and since its been in for the gearbox seals (coincidence I'm sure) it goes off balance pretty quickly. The dealer has balanced it twice now with the stepper motors disabled, both times there has been a huge difference.

I'm used to the crappy BMW fuel mapping at or around 2000rpm on a light throttle and to be honest, I've just learned to drive around that one but I just hate the balance thing as when it goes a little too far the bike hesitates on pick up.

From the response to this thread I take it that either I'm too sensitive or my particular bike seems to be the problem.

Thanks.

 

[GSwadd]

P.S. Reading posts on this site makes you realise you have problems that you never even knew existed. Your bike is about to disintegrate. No BMW paint has ever been known to last more than 4k miles. All BMW gearbox shaft seals leak. And the BMW seat gives you piles (I cant spell hemarrhoids) and ruins your sex life etc etc

I have to agree about the seat though. Did 200k's yesterday arvo, two up, and was riding along after 40 mins thinking, did their test riders actually ride further than around the block? I have tried the low position (crap), the high position (better) and now have settled on high front and low back positions even though the manual says not to. It seems the best of both worlds as it doesn't roll you forward or sit you on your tailbone if you remember to move about a little. Additionally, I always expected the flat twin to be smooth (perfect primary balance, after all), but it has worse vibration over 100kph than my old 270° TRX, which smoothed out beautifully at 120. It's not bad but you do know it's there always. I just accept it as "character" though. Should I be more paranoid?

 

[birdseye]

Seat problems? The cure is simple. Just run off a copy of your avatar, stick it on the instruments, and you wont notice the seat (or the oncoming traffic............)

It must depend on your arse shape. I've done 300 miles on mine before it got painful, and I know people who have done more than that. But I'm well padded.

Like you and many others I found the high front low rear position was best.