New to BM bikes, came from a Honda Xr650L, great thumper. So lately, i bought a '03 1150GS Adv at 125k mileage. Engine runs smooth but realised that the engine (somewhere below the tank) buzz quite prominently when rpm hits 3.8 - 4k. Is there sth i should be concern about?
GSA buzz at 4000rpm
- Thread starter pharme
- Start date
If you have the BMW ADV crashbars fitted look for a broken crashbar bracket on any of the upper fixings. They have a habit of breaking causing the bars to vibrate.
Hmmm you could be right. Yes the buzz comes together with vibrations. I'll put it at stationary and revv it up to check on the crashbar. Somehow my suspicion is with the engine. I hope i am wrong.
If the 'buzzing' you describe is in the handlebars and at the same revs - so if you increase or lower the revs it clears - it might just be throttle balancing. After balancing mine and then heading off to Italy in the summer I noticed some vibes in the bars at about 3750 if I remember correctly. After some comments from the collective here, it would seem they all do it to some extent, but of course it'll be more pronounced if the TBs are not balanced well.
Sent from my SM-N910F using Tapatalk
Sent from my SM-N910F using Tapatalk
Massive Lee
Registered user
The buzzing often indicates a problem with an unproperly fueled engine. The motor is tuned to be lean, and it is not optimal for smoothness. Even with throttle bodies perfectly balanced, the engine will be smooth until 4k RPM, then can vibrate heavily upward. The solution in my case for a healthy engine revving up easily to 6k RPM and up was to install an AFxied module that richens the fuel mixture by tweaking the signal from the O2 sensor to the DME.
Start by ensuring the throttle plate bushings are in top shape. Then set the TPS, sync the TBs.
My 2006 GSA has 133,000 miles and runs better than ever ;-)
Lee
Start by ensuring the throttle plate bushings are in top shape. Then set the TPS, sync the TBs.
My 2006 GSA has 133,000 miles and runs better than ever ;-)
Lee
This is all so insightful. Will go through some of the points raised here. TPS and TB will be last to go for but surely would like to see what's in that box. And i must say there are really good documentation here and also the net on fixing and modding the boxers. My only complain is the cost of parts are ex, often ridiculous i find.
beemer pimp
Registered user
Fleabay ! Cheaper then japs specialty from Germany,
GARAGE HERMIT X2
Registered user
just be thankful you dont own a harley,, price of spare's, add a nought to any price,
Massive Lee
Registered user
BTW Fix your fueling and the GS will happily rev to 6k rpm without blinking. ;-)
yes it seems the way to go. AFxied module and GS1100 tuning chip... i am still catching up to learn. The experience of my bare twin spark from stock and progressively bringing in mods to improve its performance is truly existential. Loving it.
Thank you Steptoe. You were spot on about the crashbar. A little tightening at the midjoint fixes the issue. The buzz / vibration is mitigated.
Yess.
i'll be reminded. Hope yours didnt see you to anything disastrous. Ride safe.
Nope,it is some years ago,it took me some time to find out where the strange noise came from..
Similar threads
