GS1150 Vibration Question?

[TxGSrider]

Just a general question here for some that might know and Ive wondered about for awhile. I read allot of old articles about the our old GS1100's and 1150's, and it seems like all the articles say the GS1150's made better power than the 1100's but seemed to vibrate allot more at highway speeds. Was this an engine balancing issue or did it have to do with the change in frame / footpegs / handlebars? Do big bore kit GS1100's vibrate more than the stock motors?

Just curious...

[dorkburger]

1150 is buzzier for sure. I'm interested in the why also. I seem to recall bigger wristpins being mentioned as a possible cause.
I have non stock, but still clip on type of handlebars on mine. it changed the buzz, but its still noticeable, especially in the bar end mirrors.

[posplayr]

The 1150's 20mm pins probably account for most of teh buzz differential. My 18mm 1166 had much much after head flow porting by an expert. See my link for Terry's head work.

http://www.thegsresources.com/_forum/showthread.php?137631-Low-Cost-High-Performance-GS1100E-Head-work&highlight=head+low+cost

[Nessism]

Rotating parts weight plays a part: pistons, pins, rods, etc. Most all larger displacement inline 4 cylinder bike engines these days have counterbalancers to smooth out the vibes.

[JTGS850GL]

I've also noticed that the 1000 and 1100's are buzzier then my 850.

[Nessism]

I've also noticed that the 1000 and 1100's are buzzier then my 850.

I'm not sure why but the 750-850cc engine size seems to be a really good in terms of smooth running for an I4 engine. I've had several small displace I4 bikes and they all vibrated more than my GS850's and KZ750. My GS1000s vibrated more than these other bikes too.

[TxGSrider]

What kinda got me wondering more about this was I was talking to a buddy of mine this weekend that has an 82' GS1100 with cams and a big bore kit, and he had the crank welded before he put it together (many years ago). He said the motor always vibrated more than it did when it was stock, but he thought it was the welded crank that might be the cause as he didn't think they (Falicon) had balanced it afterwards.

[renobruce]

The 1150 is very sensitive to balanced carbs. Mine buzzed so bad my hands would fall asleep. Now that I use a Carbtune, the buzzing is all but gone.

[dorkburger]

Second that. Mine did improve markedly after a proper full carb rebuild and synch.