the bike gods hate me!!! You gotta read this

[Anonymous]

Ok heres the story. I have a 1983 GS750 I bought last year. It ran great for a little while. Eventually I started having gas problems. It turns out the vaccum tube on the underside of the tank was shredded so I replaced that and now it starts SOME of the time. Also to cut my riding season a month shorter which is already ridiculously short in Ohio, I made the biggest mistake of my life by letting my friend just sit on it, not even ride it. Of course the bike gods immediately saw this to their advantage and dropped the bike on the pavement, causing a fist sized dent in the tank, a completely torn off headlight assembly, and a broken alternator/stator cover. Awesome.
Anyways heres the point. I spent all winter fixing it up. Replacing the cover, fixing the headlights, staring at the huge dent, etc. Finally The other day after draining my battery twice (thanks GS750 for no kickstarter!! ) I got it fired up. To my awe it actually ran great after having some gas tweaking, minor adjustments. It was 70 down here in Ohio which is clearly abnormal. It was the kind of day you can't even walk outside without thinking about how great a day to ride it was. So I pull up to the end of my driveway ready to start spring off with a bang. I grabbed a little front brake to slow me down and then the bike gods decided it was time for another laugh. My brake at first had only slight pressure. I figured it was a long winter and went to pump it to get pressure. To my dissapointment after pumping the brake it went absolutely limp. No resistance at all it feels as though it is disconected. This is the problem I am currently working on right now. I have checked the lines with no leaks. I checked the master cyclinder and there is sstill brake fluid, and its not milky so Im not thinking it is moisture. So as you can imagine I am extremely frustrated at this point. Could someone please give me suggestions for the brake/dent/gas problems I have. Hopefully with someones help I can finally beat the bike gods once and for all.

[Bolder Biker]

The brake pressure problem could be due to air in the system. The 1983 GS750 has anti-dive plumbing using brake line pressure for actuation. The result is a number of brake lines in the lower front fork area that provide a multiplicity of ?traps? once air gets in the system. The only solution is probable to purge the whole front brake system, using fresh brake fluid. Someone here (or the service manual) can provide you the best method to do this.

There is probably not much you can do about the fuel tank except continue to use it (if it does not leak now), or try to find a replacement (e.g. on E-bay or in a m/c boneyard). Several people here have recounted tales of woe about trying to remove tank dents through pressurizing the tank (with air or nitrogen). Apparently, the risk of opening up the tank seams is real. Specialists in tank repair do exist but I expect that the cost would be higher than you would like.

Hang in there. I have had my 1983 GS750ES for 21 years and found it to be a reliable and satisfying machine (except for those pesky GS R/R gremlins). If you can get the bike right at a reasonable cost in money and effort, you will not be disappointed.

BB

[Anonymous]

can anyone tell me the correct way to bleed the brakes. My book is for 1979-1982 gs750's. It has no mention of the anti-dive system so I don't know what I have to do to the anti-dive system if i bleed the brakes. What would happen id I didn't touch the anti dive system and just bleed the brakes normally?

[Bolder Biker]

I can send you copies of the pages from the correct service manual if you have access to a fax machine. If so, send me a PM with the fax number and a time you can receive the transmission.

Basically, the procedure is the usual brake bleeding method using the following order:

1. Left anti-dive
2. Left caliper
3. Right anti-dive
4. Right caliper

i.e. always start with the left side. If the problem is air in the system, you probably will not purge it satisfactorily unless you include the anti-dive units in the purge sequence.

You may have to repeat this sequence several times to get rid of the air. If the lever still feels spongy after several bleeding sequences, you can remove the anti-dive modulator from the anti-dive assembly so you can tip it upwards, enabling air to be more easily purged from the unit.

Only use DOT 3 or 4 glycol-based brake fluid?..not silicone- or petroleum-based

BB

[Anonymous]

the copies would be most helpful thank you. I do have a fax, but unfortunately I do not have a home phone (switched to cell phone). You can fax me through cable or scan them to me if you have access. Also I wanted to let you know not only is the brake lever completely limp but also in its neutral state it also is gripped onto the caliper, would that be normal for air in the brakes. And usually when you have air in your lines wouldn't it just feel spongy not completely disabled. Thanks for your replies it is helping tremendously. thanks .

[Bolder Biker]

the copies would be most helpful thank you. I do have a fax, but unfortunately I do not have a home phone (switched to cell phone). You can fax me through cable or scan them to me if you have access. Also I wanted to let you know not only is the brake lever completely limp but also in its neutral state it also is gripped onto the caliper, would that be normal for air in the brakes. And usually when you have air in your lines wouldn't it just feel spongy not completely disabled. Thanks for your replies it is helping tremendously. thanks .

I can scan them tomorrow if you send me a PM with your e-mail address (can't send attacments to you using PM).

Regarding your other questions, you have probably moved beyond my level of competence in providing a good answer. I am not sure what you mean by "gripped"......and yes, the brakes should just feel spongy if the problem is air, unless you have a bunch of it in the system. I suppose there could be a master brake cylinder problem. You might try PM'ing Earl Fornes ("EarlFor"), who is extremely competent in all thing GS. I would also suggest Billy Ricks but I am not sure that he is currently available. Also, if you haven't already done it, you can do a search through past Technical Forum posts using appropriate search parameters.

BB

[SqDancerLynn1]

If the lever just went limp It sounds like the master cyl may be frozen NOT releasing You may have to disassemble the cyl and rebuild / clean it

[Anonymous]

Ditto re: master cylinder problem. There should be a rebuild kit available through your Suzuki dealer.

[Clone]

Your tank dent could be pulled out if it is not too sharp a dent or on a corner. I pulled the one on my Yamaha out by hot glueing an elevator bolt to it and then pulling on it. The dent popped out and then I peeled off the glue, up close you can still see where the dent was, but from a distance, you can't.

Hey, please please, please, measure the diameter of the shifter shaft on your bike.
Thanks

[Bolder Biker]

I have sent you scans of the 2 pages on brake bleeding from the service manual. Since I agree that the ultimate problem probably resides in your master brake cylinder, I will be sending you scans of the 4 pages relating to that.

Good luck,

BB

[Dark Jedi]

Your tank dent could be pulled out if it is not too sharp a dent or on a corner. I pulled the one on my Yamaha out by hot glueing an elevator bolt to it and then pulling on it. The dent popped out and then I peeled off the glue, up close you can still see where the dent was, but from a distance, you can't.

Hey, please please, please, measure the diameter of the shifter shaft on your bike.
Thanks

I bought one of those glue-and-screw dent pullers you see on late night TV (Hey, $12 at the flea market, Good deal)
It worked great on dents that have no crease, and OK on dents that had creases. JC Whitney has them for about $19 IIRC. I see no reason it wouldn't work on a GS gas tank. it's not like they are made of inch thick armor plate or something. :?

[Anonymous]

hey everyone thanks for the replies, Clone do you know what kind of glue you used to attach the bolt to the tank, the dent itself looks bad enough all I need is a bolt stuck onto it. :? . And what exactly did you mean by measuring the shifter shaft? Thanks

[Clone]

Hot glue gun glue, I don't really know if there are different types, there are different colors. Once the glue cools and you pull out the dent, you just pick at the edge and start to peel it off. It will come off and not stay permanently. I actually had the whole bolt pop off because the paint wasn't clean enough and I ended up on my backside across the garage. Yeah, laugh it up now honey, my wife will never let me forget the experience. The glue will come off so don't sweat that you will have stuff stuck to the tank.

The shaft that the toe shifter attaches to, it comes out of the left side of the engine near the bottom. A ruler measurement will be fine, 10mm, 8mm, whatever you can eyeball is ok.
thanks.

[daveo]

The shaft that the toe shifter attaches to, it comes out of the left side of the engine near the bottom. A ruler measurement will be fine, 10mm, 8mm, whatever you can eyeball is ok.
thanks.

I have an 81 750 E sitting in the yard, measured behind the chain cover(by the sprocket, not the knurled part where the lever goes), the shaft itself is about 10.75-11mm