Bike revs to redline. . .

[The Lorax]

check to see if the linkage is hanging up on the clamp for the #3 carb. I read somewhere that if the screws that tighten the clamp aren't far enough away from the throttle linkage, it can catch on the screw or the clamp and keep the throttle open. maybe it maybe not, just a thought. have a nice day and ride safe

[TopCatGr58]

What's his hangup??

Hey Lorax,

That's what I was going to suggest he check. Yep, the clamps that hold the carbs onto the intakes can get hung up on the linkage mechanism. He needs to see IF he can push the linkage to see if it will move farther closed than it does with the cable off! IF so, then needs to see where it's hanging up and change it so that the linkage doesn't hang up, then he should be able to put the cable back on and all should be right in the world again!!
T.C.

[b.walker5]

... is it possible that a vaccuum line has come off and caused this, I doubt it, but it can be checked easily.

Theyre a mystery to me too but as I understand it the vacuum works on the top of the diaphram lowering the pressure to open the slide. If the vacuum line was disconnected the sppring pressure on top of the slide would simply close. The over-revving described has to be a mechanical issue with the cable, linkage, or jamned throttle plates etc.

[DGXSER]

Yep, DBeardslee (aka Doug) has it right. I always refer to the Cat-in-the-Hat song Calculatus-eliminatus. The way to find that missing something is to find out where its not!

[fabricgator]

Twist throttle free play...

I was going to ask about the twist throttle free play is/was....

Throttle free play should be inspected regularly and adjusted as the cable tends to stretch over time. Part of your pre flight inspection.

I will explain it as the amount of free play movement of the RH twist throttle mechanism on the handlebars. The distance that the throttle handle moves freely before you can begin to feel the carburetor throttle spring resistance.

Should be set so that there is a small amount of movement to ensure that when the throttle handle is released, that the carburetor butterfly valves close completely to the point that the idle set screw is calibrated to. Thus, also ensuring that there is not any spring tension on the throttle cable at all times.

The manual gives instruction on checking/adjusting this....

So, if the carbs were mechanically binded at the carbs themselves, the free play would be excessive (sorry, I meant to say "XSive") AND if the cable were routed incorrectly or the sheath were out of position or pulling, there would be no free play at all....

I did have a hard time, for some reason, explaining this. Could someone please clean this up for me?

[Larrym]

Insert Tab-A into Slot-A after Folding Along Dotted Line-X.

I understood just fine.

But then we're both able to "see" the pictures in our heads of what it looks like cause we've both had our faces in those areas.

Might have been a real head-scratcher for someone who's never even pulled off the fuel tank though.

[yamtom]

I hate to say this

Doing good so far, but what about this ,, is it possible for some piece of something to actually break away in the carb or air cleaner and travel inside to jam things open??? JAT

[xs11lover]

Ok so you removed the throtle cable from the carbs and it's still stuck flat open. Does the clip you remved the cable from move up and down freely?

[WMarshy]

Sounds like maybe one or more of the buterflies are stuck open. Could it even rev up if the buterflies were closed but the slides were stuck open? Your best bet would be to take the crabs off and check everything over, see if the buterflies open and close freely and make sure the slides move smoothly. Anyone know if a bad (jammed) buterfly seal would make one or all stick open?

Please correct me if my theory is wrong. If you started the bike up with the cable removed and the air box off would/could you see one or two slides lift immedately if those buterflies were stuck open? Seems possible but it also seems like it wouldnt rev so freely with just one or two carbs WOT, let alone start easy...

[fabricgator]

I am curious if just one butterfly could be open....

Seems that the linkage would have to be seriously out of position, and that may just be the situation. Asides from the spring/tension pin at the synchronization adjustment screws, I can't see where there would be much play for a single or more open butterfly's.

I'm in for a dollar that the intake clamps caught the linkage during throttle twist.

I hope the gremlin reveals itself here in the future.

[Yard Dogg]

It's possible for one of the throttle flap screws to work itself out and the throttle flap to get stuck against the inner carb body keeping all of them open. The throttle flaps are a machined fit. If one of em slides out of the throttle bar running through the carb body even a little bit it can easily stick open. I think you should definitely remove your carbs and check things out. You don't want a screw in your cylinder.

[vileneeds]

This is exactly what mine is doing. Has been for a couple weeks. Am at my wits end.

[skids]

I had it happen once when the "goose neck" at the throttle grip was broken.

This is exactly what mine is doing. Has been for a couple weeks. Am at my wits end.