First off, thanks for this wonderful board, I have lurked for some time and gleamed lots of nice info (expecially that fork tool suggestion!). All that info has got me up and running, as I picked up 2 GS550E's (Both 89's, but one is a 89.5, so it came with 90 handlebars) for a great price. One is a runner, and my daily driver. The other (with 7K less on the ODO) was wrecked, and has no title... so its a project, or for parts.

Well my daily driver has lots of buzzing. It gets hard to ride after 1/2 an hour. I know bikes have some vibration (I have 5 including these) but I would like to tone it down a tad. Its vibrating worst from 4000 rpm on, and will do it while sitting so it is not the front suspension.

Ive tried bar ends, weighted bar ends, filling the bars with sand, 2 types of gel grips, filling the bars with shot... nothing seems to do the trick. The current weighted bar ends seems to help a bit, but is still isnt comfortable.

Should I be looking at balancing the carbs, or is this a symptom of a bigger issue? The bike seems to sound good, and shifts well, drives and responds well.

Any ideas will be greatly appreciated

Thanks
Bryan

is the engine bouncing around ? it shouldn't be at all. since you say it's vibrating like mad when it's sitting still, me thinks you have something going wrong with the engine or a head bearing (steering head, not engine head) issue.

how's it handle in turns ? does it clunk when you rock it back n forth with the front brake engaged ?

No clunck, and it eats turns very nicely.

I wouldn't shay it is a large shake. Best I can describe it is the electric chair game at arcades.... you have to grip while it buzzes, and see if you can hold on without it hurting too much.

I checked all the bolts, making sure they were seated well.

Do these bike have rubber mounts that may be worn out?

First, I would make sure the engine mounts are torqued to spec. Then I would balance the carbs. Note, for carb balancing to be effective, you will need to adjust the valve clearances first.

Good luck! Just ask if you need more details. 

Valve clearance... I always hate having to do that. Got to do it on my CB650 this week. Same process? TDC,  then check the spacing under the tappet?

I have a Clymer manual, so I should be able to get it done.

Quote from: Azzy on July 07, 2008, 08:14:36 AM
Valve clearance... I always hate having to do that. Got to do it on my CB650 this week. Same process? TDC,  then check the spacing under the tappet?

I have a Clymer manual, so I should be able to get it done.

Just follow the Clymer and you'll be fine.

Also, check out the wiki. It includes a shim size calculator and a HOW TO video:
http://cgi.stanford.edu/~sanjayd/gs500/Maintenance/CheckValves

Thanks for the link... 

Man, Im spoiled. My SR250 is remove 6 bolts, the covers, and adjust tappets, dont even need to move the tank.

This one looks like a good evening or Saturday project.

Now for balancing, is my homemade manometer going to cut it, or do I need to set the vacume to a certain level? It worked to sych the inline 4 on my Honda.

Quote from: Azzy on July 07, 2008, 08:32:09 AM
Thanks for the link... 

Man, Im spoiled. My SR250 is remove 6 bolts, the covers, and adjust tappets, dont even need to move the tank.

This one looks like a good evening or Saturday project.

Now for balancing, is my homemade manometer going to cut it, or do I need to set the vacume to a certain level? It worked to sych the inline 4 on my Honda.

if you've ever removed a tank and done any valves before it's maybe a 2 hour job

ya, your homemade water/oil/whatever manometer is cool. the sync shouldn't matter so much as the valve adjustment. there is a noticable difference between poorly adjusted valves and proper clearances. seat of the pants, at least.

good luck

Carbs that are out of synch` can cause vibration across the whole rev range due to one cylinder doing more work than another, particularly if the valve clearances are out of tolerance as well......unless someone has had it apart at some stage in the past and messed up the balance-shaft timing!

Balancing is not a difficult process and its covered in all the various manuals. A homemade manometer will get you a "Barn-door" setting but a proper, calibrated balancing tool will make the job easier and give far better results. I bought on of these on ebay http://www.carbtune.co.uk/ for less than the price my local pro` quoted to balance the carbs on my old 400/4.........if you see one snap it up, I have used it many times and its always given excellent results, they really are a fantastic piece of kit.

For a write-up
http://www.roadracers.co.uk/carbs.htm

How would I know if the balance shaft timing is off?

While I have most of it apart, that is.....

The balance shaft is gear driven from the crank, I dont know for certain on the GS5 engine but I would assume based on experience of other similar engines that there will be a timing-mark between the crank and balance shaft gears that needs to be aligned. However the balance shaft and the gears are inside the crankcase so unless you go to the trouble of spliting them there is no way to check......Is there anything to indicate the cases have been apart before?

Not that I can tell. There are so many things on both these bikes that were switched, It could have been, but I doubt it.

Its a possibility........ but a long shot.

Tried a carb balance with new plugs?  http://cgi.stanford.edu/~sanjayd/gs500/Maintenance/5CarbSync

Also, a low idle will cause vibration.Idle should be 1200 rpm.

Well, got around to working on this bike today. Checked the valves, they are all around .04mm (That I can tell) and balanced the carbs. It accelerates smoother, but the vibration seems to have gotten a tad worse.

(Although the ride is nicer with the Katana 600 rear shok that I tossed on there while I was at it...)

Gonna go ice my hands now , and call up the local shop and see if there is anything he can do.

Did you ever get the problem resolved?  I got the same issue.

My wifes GS500 was missing the little rubber piece that goes in the front fuel tank bracket and so the tank was moving around and vibrating a lot at high speed.  Got a new one for $5 from babbits online, much better now.  Still some vibration, but I chalk that up to the bike being old without great suspension.  Compared to my SV650, it vibrates quite a lot at 5000+ rpm.  I've heard renthal aluminum bars help a lot with that.

Rubber thingy is intact (side note.. that fuel hook up system? Who the heck designed that!?  ) but I think the vibration, while smaller in the overall amplitude fo frequency, is feeling worse 9because it happens faster. That make sense?

renthal bars? Well, Im going to see about getting this tuned a bit better, before I go out and start buying handlebars that may or may not solve the problem for me.

Thanks for the tip though!

Since you've checked the usual stuff...

Are your bar ends intact ?

Have you tried this yet ? http://gstwins.com/gsboard/index.php?topic=41264.0

Gotta death grip ?

Death grip? Possibly, but I also have had medical problems in the past with repetitive strain disorder, so I may be a tad more sensitive.

Tried the shot thing, tried sand, my last attempt was with adding a steel bolt to the bar ends that stis way further into the grip, and weighted that down (as i calculate it, it would be like having 3" extra on the bar ends)

But those bar ends arent stock.

Any tricks for pegs?

I think this is not a normal thing, because the vibration isnt just in the bars, its all over and very uncomfortable at this point. Doesnt help I suck at the whole carb and valve thing.