Design change GS 1150 to improve Vibrations?

[joe.d]

MY GS1150 does the same thing....
4-5000 revs and vibrates like a sob
when i first got the bike i thought there was something seriously wrong
but i guess it sounds like its a common thing, and ive basicly gotton use to it, I thought maybe changing the gearing on the rear sprocket , to shift gear change points couse basicly arround town it drives me batty, which way would i go any ideas?

allso when I first got my 1150, my swinging arm pivet bolt was finger tight, and made me think I had bought a real lemon, proper maintenance changed the whole feel of the bike,

I run flat drag bars on risers mounted where the orignal clipon mounts were mounted...and im sure that contributes to my bikes vibration

[earlfor]

I havent a clue why the difference. If it is the crank, it seems strange to me that apparently the majority of 1150's have an out of balance crank.
At 4-5000 rpm, my mirrors dont even go out of focus like they do on my 750.
I get a noticable vibration level above 9K, but that isnt a big problem.

Earl

Mines pretty bad Earl. I suspect slipping the crank out and sending it to falicon would reward me but I`m to sorry. :?

[robinjo]

Go and ride a Harley with a rigid mounted motor in it and THEN ride the 1150

[mpogue]

Mine was pretty bad. I'd get numb fingers after a ride. I changed the rubber engine mounts and it made a drastic difference. A few weeks later I synched the carbs and it fixed the vibration even more. It still has a buzz at 4000-4500 rpm, but nothing compared to what I had previously. After a 850km ride, I had no numb fingers or anything. I'm just trying to figure how bad are the vibrations you're getting.

I guess I've been lucky as well.

[kz]

Earl and tyler1150 you are both definitely giving me some hope that it is possible to fix the problem, You are the first people I here saying that they don't have vibration problems with the 1150.

I spoke to a former dealer here in Sweden and he said that they had a lot of complains regarding vibrations at the time then the GS1150 was sold new.

The vibration problem was according to him only related to the 1150 and not to the earlier models.

One issue at the time was that the frame cracked just in front of the side stand, mirror fasteners broke, fairing fasteners broke etc.

If the frame was cracked the vibration went much worse, they had to take back some bikes and weld the frame on waranty at that time, he said.

Suzuki gave out recommendations that it was very important to retorque the engine mounts, different handlebar and fotpeg weights where tested, i.e. the weights on 84 and 85 model differs.

His experience was that the vibration problem was more or less unsolvable.

However, unsynchronized carbs and wrong torqued engine mounts made it worse.

His personal thought is that the problem is rather related to the frame design or the mounting design of the engine when to unbalance of the crank.

I read that tyler1150 has a GSXR fork maybe that is a solution???

Earl is your 1150 "pure" stock? Even the rear shock absorber?

/Karl

BTW:

Having second thoughts about rebuilding my engine if I have to live that @?@@@?? vibrations....

[cbxchris]

If I ever have to take my 1150 down I am positively going back with a 1100 crank. I have not tried new rubber engine mounts. That will be a good winter time project. I know on drag bikes most people eliminate those. You should feel a 1150 then. 8O

[Dink]

Chris replace the rubber bushes, it is a ten minute job. to finish the hour off re-torque your engine mounts and see if that helps.
Dink

[Anonymous]

Thanks guy's, this discussion has shed more light on the vibe problem than I'd ever heard before. I've done all I can do to my "86" model, but the mirrors may as well not be there, aboye 4500 rpm. It seems I must have one of the worst vibrating ones, my "85" model isn't nearly as bad, but much worse than the 1100's. Thanks for shareing your imfo. And I still beleive that Suzuki knew early about the problem, thus the vibration dampeners in the bars & footpegs & the rubber mounts.

[earlfor]

Karl, my 1150 is stock and all original parts. The only changes I have made from stock are different rear turn signals, a xenon headlight bulb, an
electronic digital tachometer, and two inches of foam removed from the seat to lower the sitting position. I replaced the stock leaded handlebar ends with hollow stainless steel tube which if anything, would make vibration worse, but that made no difference. I have replaced the R/R and stator, but it didnt vibrate with the stock stator either. I replaced the clutch linings too, but it never vibrated with the old linings either. The 1150 does not vibrate or shake at all at any rpm and there is no high frequency buzz at high rpm. If it wasnt for the tachometer, I wouldnt know the engine was running at highway speeds.

I have found the bike to be fussy relative to carb synch. If the synch is a little bit off, it makes a big difference. Also, the stock main jetting is Mikuni #120's on the 1 and 4 cylinder and #122.5's on the 2 and 3 cylinder. I could not get an equal plug burn with that jetting and once in a while, the 2 and 3 cylinders would skip/spit because of it. I am running 122.5's in all carbs now and the plug burn is better. The bike runs even smoother.

I have installed a Dyna 2000 ignition system. I have found the bike does not tolerate the slightest difference in ignition timing between the 1,4 sensor and the 2,3 sensor. It will run noticably rough if there is one degree difference.

The Dyna 2000 has programmable ignition timing curves. I have the full 32 degrees of advance programmed (delayed) until 4500 rpm is reached..
Thats about 1000 rpm later than the stock ignition advance curve.

The factory service manual specifies 89 octane fuel. The bike seems to run smoother on 89 than it does on lower octane.

In short, carb synch and ignition timing seem to make the biggest differences in smoothness.

The bike starts instantly when cold and idles at a smooth and steady 800 rpm when cold. Once at normal operating temperature, it idles at 1100 rpm. Normal oil temp is around 190 degrees.

Earl

Earl is your 1150 "pure" stock? Even the rear shock absorber?

/Karl

BTW:

Having second thoughts about rebuilding my engine if I have to live that @?@@@?? vibrations....

[lhanscom]

On the other end of the spectrom (not stock), I don't have much vibration, it buzzes a bit around that 4500 area, but nothing that bothers me much, hands don't go numb, and mirrors are fine. My crank was balanced by Falicon, and I have the 1229 kit in it. Ignition is the Dyna S. I noticed a big difference when I balanced the carbs, it seems these engines are very particular on the amount of power each cylender puts out. Just a thought, if ignition timing, and carb balance makes a significant difference in vibration, wouldn't compression also make a diffence? So if one cylender is lower then the rest, vibration would go up?

[mpogue]

Are you guys saying that at 60/70 mph your mirrors are clear? :? After all I've done, everything in my mirrors are still blurry. The bike rides great and has what I see as minor vibration. At 4000-4500rpm I do have some fairing buzzing, but thats it.

[earlfor]

At 60 mph or less, my mirrors are the same as if the bike is sitting still without the engine running. At about 65 mph, I can see traffic to the rear clearly (perfect focus) at any distance up to 1/4 mile or so. There is some vibration evident in viewing more distant images, but it is not a problem.
At 75 mph and above, the mirrors vibrate enough that I cannot tell the difference between a Ford and a Chevy at distance, but that is about all. At 100+, they are not much use. I dont feel the vibration at any speed.

I forgot about one modification. A while back, I wanted new mirrors and couldnt find any I liked with long stalks. I bought the style I liked and hacksawed the stalks in half. I then bought a 5" length of 3/8" inside diameter copper pipe for each mirror stalk. I drilled the inside of the copper pipe the same diameter as the outside of the mirror stalk so the mirror stalk would insert into the pipe at each end. This was to increase the length of the mirror stalks. I used J.B. Weld to glue the mirror stems into the pipe ends. I think the effect may have been about the same as
leading the handlebars. Mass is increased and vibration apparently is deadened. That wasnt my original intent though. :-)

Earl

Are you guys saying that at 60/70 mph your mirrors are clear? :? After all I've done, everything in my mirrors are still blurry. The bike rides great and has what I see as minor vibration. At 4000-4500rpm I do have some fairing buzzing, but thats it.

[lhanscom]

At 80 I can look into my mirrors and they're moving a bit, but the focus is fine. I think the movement has more to do with wind and road surface then engine vibes. When over 100, I haven't taken notice of my mirrors shaking, but I'm usually concentrating more on what's in front of me at that point.

[mpogue]

I think I see why you're mirrors are clearer than mine Earl, you have them mounted on the handle bars. Mine is on the fairing.

As for Luke, if yours is a ES, your mirrors are on the fairing. You're probably right about some of it being road and wind. I'll have to pay more attention at low speed to see when the mirrors get blurry at what rpm. I remember from my last ride, I was lucky to guess what colour the vehicle is unless he's real close.

Thanks.

[lhanscom]

Currently I'm in ES mode, so the mirrors are on the fairing, I've also been in E mode, and had no problems with the mirrors.