Crashed GS550 this morning due to high rpm in throttle! Need some help...

[tkent02]

Not to argue but I believe I labeled them correctly. Have a read here:

http://www.motionpro.com/tech/articles/throttles_and_throttle_kits/

Next to last paragraph labeled "Notes."

Not your nickname, it is the common usage on motorcycles, but there is no pushing.
How can you push with a string?
One pulls open, one pulls shut.

If it was truly push pull, there would be no return spring and only be one cable, like a lawnmower throttle, and the inner would have to be solid stiff wire. Like a lawnmower throttle cable, a solid piece of single strand wire, stiff enough to push. Another example of push/pull is the single steering cable on a motorboat, it uses a very stiff inner cable.
These motorcycle cables are floppy multiple strand wires, and slightly loose in their housings, as they are designed only to pull smoothly, not to push.

Also look at how the outer cable just slides into the adjuster, this cable cannot transmit a push, as the outer cable just pushes out and falls apart.
If you still don't believe it, try removing the cable that pulls the throttle open and go for a ride. Tell me how well the other cable pushed the throttle open.

[Nessism]

I agree with Tom, motorcycle cables do not push, they pull.

For some reason the motorcycle industry, at least the one in the aftermarket, holds steadfastly to the mistaken "push/pull" naming convention for the throttle cables in question. Too bad no one is smart enough to stop with this sillyness and rename the cables properly.

As a side note, in that motion pro link they state the following:

"Notes: Do not consider any single-pull throttle (only one cable used) to replace any push / pull throttle (one pull cable and one return cable)."

Key idea here: use a proper TWO cable arrangement for safety.

[Suzuki_Don]

Can someone please explain why on the VM carbs we have a pull/pull cable system with two cables and on the CV carbs we have only one throttle cable to pull the butterflies open. Is it that the slides are more likely to jam in the corresponding cylinders where they reside as opposed to a shaft turning in a bore.

On another point and I don't mean to hijack this thread, is there some way to decrease the spring pressure on the CV shafts as I expect the twistgrip will have a heavy feel to it when I get the carbs assembled back on the bike .

EDIT: Fruedian slip I Think.

[supergrafx]

I inspected the throttle cable under-neath the gas tank this weekend. The mechanic that supposably serviced my bike made it easy as I was shocked to find the previous bold that kept the gas tank attached to the bike's frame missing?!? Perhaps the gas tank missing it's bolt to the frame caused the binding in the throttle cable since the gas tank must have been moving much more left to right as I made a turn without the bolt present. Well, I'll stop complaining and give forth the pics to my findings:









I also noticed that the breather hose that attaches to airbox from the engine's cylinder head was loose and not attached, something I had previously discussed with the would be mechanic, but probably not reattaching. I fear now that reattaching this hose will make the sync job that was given to my carbs, out-o-sync...

I still have been unsuccessful in finding the 1979 gs1000s throttle cables. I followed the link to motion pro's site and see that they make custom cables? I will write them an email. Perhaps 4 inces less than stock? The throttle cable I have now is stock, with the digits: (47001_3-38-A) on the cable. In the parts the previous PO gave me when getting the bike, I found an identical cable with the same part number that must have been the bike's return cable. The metal wired stand within the cable seems a little damaged though.

[cloudbreakmd]

Reattaching your breather hose will not affect your carb sync.

[tkent02]

Not sure on your exact model, but having the cable go over that wire loom hook, and over the tank front mount rubber looks incorrect, will probably leave a very sharp bend, easily kinked farther up near the steering head. The cable should go between the frame rails above the carbs, then go under the tank mount rubber and through the fork legs in between the upper and lower triple clamp to the right of the steering head.. out between the guages and the bars and out parallel to the bars to the throttle grip.

It is this type of thing you are looking for, incorrect routing will cause problems...

Look for the correct cable routing in the Suzuki manual, and inspect your cable for any kinks or damage in the steering head area.

The missing tank bolt won't cause this problem, but is hazardous in itself, if a shop did that they are morons.

Get the cable routing right, this is serious.

Your clutch cable is all boogered up too.

[robertbarr]

Are those home-made headlight ears? Curious.

That has to be the oddest clutch cable routing I've ever seen, and I kind of wonder how it even works (although I'm sure it does).

[cloudbreakmd]

Peter bought the headlight ears off of Fleabay. I suggested the cut inner tubes to keep them from scratching the fork tubes. The clutch cable and throttle cables were routed funny because of the clip ons.

[Big T]

That throttle cable is wrong in so many ways.

AS Tkent mentioned, in photo #2 the cable runs between the frame rails (where all the wires are) behind the coil for a straight shot from the back of the coil to the carbs. You can see where the tank rubs on it where it runs outside the frame rail.

At the front, the loop back is too tight, causing a kink.

I'd suggest getting throttle cables for a 1979 GS1000S, which is what I did when I put lower bars on. They're at least shorter than stock.


It's a shame so many hacks have worked on this bike. Keep posting up your problems and they should get resolved before good weather comes.

[cloudbreakmd]

Gabe,
You'll be fine. We'll all help you if you're willing to turn the wrench. I wish I had finished the bike prior to Peter finishing it himself

[supergrafx]

Update

I got the two gs1000s throttle cables from flatout and last week tried to hook them but hesitated by thinking they were not correctly put on since their is a slight problem I think with the throttle right-handlebar assembly. I hooked up the cable that pulls the slides open and sure enough when I open the throttle the slides open and when I release, I hear "the thump" from them closing! When I release the throttle after the "thump" the throttle resets back to itself, however, I can forcibly close the throttle 4-5mm more if I force it. The thottle assembly makes a click click noise when I force it back all the way. I then disconnected the cables from the carbs and I am still able to "forcibly" close the throttle 4 to 5 mm more without the cables connected to the carbs what-so-ever. Which is why I'm thinking the problem lies with the thottle assembly perhaps and not the cables or carbs?

I talked to a guy at work who mostdefinatelly won't help me in my
dillema but I keep annoying him with questions since he used to have a 750 L with VM carbs I think back in 79. He said that my throttle assembly should not have this little restriction I am feeling in closing the the throttle. So, I'm at a loss... should I scour ebay for a 77 assembly? Looking at the assembly's internals, I can't see where the restriction is happening. I haven't lubed the new cables yet, but I wouldn't think this would cause the throttle handle to restrict itself those mm's before a fully closed stature!?

On another note. I've been looking at my model's harness and eletrical blue print from the gs550 service manual and trying to make sense of it all. I will post pics tomorrow but I've basically cut most of the copper connections off, tinned up new ones and added new spade connectors to most of them. I've totally redone the area in the headlight, up at the guages, the stator cables, the red cable plus the sense wire to the orange line from the ignition switch cable for Duanage's reg/rec I got in the mail, and it looks like all I need to do is hook up the new left handlebar switch to the connects and I'll be done.

Maybe I should have ordered the clutch cable from a 1979 gs1000s since I'm sure this would be shorter than a stock gs550 cable, am I right? I guess my main concern is getting these thottle cables working right. Weather is getting nice and I need to get to work soon without having to get rides from others. It's getting old.