83 gs750es 'tank slap'

[Anonymous]

I am confused... Under decelleration I get massive tank slap. I checked the boards, and found a few other people with the same problem. Is it just the nature of the bike to do that, or is there something that can be done to fix it?

[Bert Patterson]

Re: 83 gs750es 'tank slap'

I am confused... Under decelleration I get massive tank slap. I checked the boards, and found a few other people with the same problem. Is it just the nature of the bike to do that, or is there something that can be done to fix it?

How massive? I get a shimmy at lower speeds on decelleration, but most of it has gone away with the addition of a fork brace (redundant, I guess, since there is already one under the fender).

I tend to take my hands off the bars to stretch a lot on decelleration - when it starts to shimmy, I grab 'em pretty quick.

[Anonymous]

well, it starts out as a minor shimmy... then within a few seconds, if I dont put my hands back on the bars, I have a feeling she might buck me off. I had an 02 R6, and I could ride for miles without any kind of shimmy.. So, there my questions comes in.. is it just the nature of these bike to do that? These bikes being any older bike..

[Anonymous]

my gs850g has no shimmey at all.

[Anonymous]

well then youre lucky!! lol

[Anonymous]

.. So, there my questions comes in.. is it just the nature of these bike to do that? These bikes being any older bike..

Absolutely not! My 1983 GS750ES has not the slightest hint of a "shimmy" on deceleration. I am sure the experts will suggest possible causes.....I would wonder about front tire condition and stearing head races/bearings.

[Billy Ricks]

It's not in their nature, as long as you don't push them further than they were intended to be pushed they are stable if everything is right with them. Check the steering heads bearings. Clean them up and reinstall them. If you don't know the procedure for tightening the steering stem I can post it later. It's in the manual if you have one. Could also be a wheel out of balance or flatspotted.

[Bert Patterson]

I suspect my occasional little shimmy is more a road condition factor than anything else - Wisconsin is the heart of the "buckle-belt."

[SqDancerLynn1]

A quick way to find out is adjust the steering head brgs, just tighten it up 1/8-1/4 turn doesnt take much That is what was causing the problem on my GS850. It wouldn't hurt to take it apart and lube the bearings. With the bike on the center stand it should turn lock to lock nice and smooth. If it catches in any spot you will have to replace the bearings. IT"S not that hard to do.

[Jethro]

No shimmy here- smooth through 130mph.

[Anonymous]

"Absolutely not! My 1983 GS750ES has not the slightest hint of a "shimmy" on deceleration. I am sure the experts will suggest possible causes.....I would wonder about front tire condition and stearing head races/bearings."

Well, Finally someone who doesnt have that problem.. Well, I guess that makes me feel both better and worse about it... Better.. I know it can be fixed, worse, I dont know where to start... lol

"It's not in their nature, as long as you don't push them further than they were intended to be pushed they are stable if everything is right with them. "

This usually happens at about 50 over that and I havent taken my hands off the bars...



"A quick way to find out is adjust the steering head brgs, just tighten it up 1/8-1/4 turn doesnt take much That is what was causing the problem on my GS850. It wouldn't hurt to take it apart and lube the bearings. With the bike on the center stand it should turn lock to lock nice and smooth. If it catches in any spot you will have to replace the bearings. IT"S not that hard to do."

Could you explain how to do that please?

[moto_dan]

Response from your PM....

83gs750es wrote:
I was wondering if you ever found out the problem for the tank slap on you 83 gs750. I recently purchased one and its doing the same thing. Looks like this is a common problem with this bike. Is it really a problem, or just a design flaw? I guess its always safer to keep both hand on the bars... Thanks.

=====
I found that the correct size tire(100/90,80/16) in good condition properly inflated(35-40psi) took care of it. If my tire gets down in the 30psi range it will still shake some. Hope this helps.

[Anonymous]

Re: Response from your PM....

I found that the correct size tire(100/90,80/16) in good condition properly inflated(35-40psi) took care of it. If my tire gets down in the 30psi range it will still shake some. Hope this helps.

I checked the tire and air pressure, tire size is stock, and air pressure was at around 22psi, I inflated it to 40, but it still has that problem.

[oldschoolGS]

If nothing else is obviously wrong, it is probably a loose steering head-you do need a special socket tool to tighten this up. The part number is in the Suzuki service manual. There is no design flaw- I have 45,000+ miles in the saddle of one of these and can attest that these 58in. wheelbase bikes are very stable on and off the throttle. If something is not loose then something is bent. Ride On, Ed.

[Anonymous]

Re: Response from your PM....

I found that the correct size tire(100/90,80/16) in good condition properly inflated(35-40psi) took care of it. If my tire gets down in the 30psi range it will still shake some. Hope this helps.

I am running a Metzeler ME33 Laser in one oversize (110/90-16) at the owner's manual recommended 32 psi for 2-up riding (solo is 28 psi but I'm too lazy to switch pressures depending on whether my wife is with me ). I think that this pressure is fine for the Metzeler, as well as the OE Bridgestone. Incidentally, I think the ME33 is a fine front tire for the GS750ES. On back, I now use a Metzeler ME550 in a one oversize (130/90-17) at an owner's manual recommended 2-up pressure of 40 psi (solo is 36 psi). Interestingly, the ME550 is about 6 to 8 mm narrower than the ME55A Metronic of nominally the same size......chain guard & brake torque arm clearances that were minimal with the ME55A are now generous.