Idle speed adjustment knob

[SThelper]

Hi,

I'm trying to do some long distance ST1100 troubleshooting and was wondering if it's possible to unscrew the idle speed adjustment knob far enough so that the threaded part comes out of the carb bracket. Supposing this happened, how accessible is this part of the carb assembly? Would a person have to remove some panels/bodywork to get in there and screw it back in? If anyone knows of pictures or diagrams that show this area, please let me know.

Thanks in advance,

Mike

P.S. The bike is a 2000 ST1100

 

[George]

It is possible to unscrew the idle adjuster. Only impact would be low idle speed (to the point that engine will not continue to run without throttle assistance.)

To screw it back would require multiple panels as the bell crank is well hidden from view.

 

[Martin_b]

No need to remove the airbox. Just take the necessary panels off to allow removal of the fuel tank. That would be the seat, left and right side panels, and the fake fuel tank cover over the airbox.

Then disconnect the three electrical connections at the top of the tank.

Don't forget to undo the one electrical connection at the left side of the tank hidden in there under the left side panel.

Disconnect the fuel line and plug if the fuel level is high.

Undo the four bolts holding the tank in.

Remove tank.

Sometimes it can be difficult to remove the front of the tank from under the airbox. I can do it on my 92 but it takes some fiddling. If it proves to be a problem, remove the top of the airbox and the filter and then loosen but don't remove all the way the screws that hold the airbox to the carbs.

Once the tank is out of the way, it's very easy to see and access the end of the idle adjusting cable thingy.

Oh, and on my bike, I can remove the panels and have the tank out in 15 minutes or less.

 

[SThelper]

Thanks for the help guys. Does anyone know where I might find a picture of a carb assebly that shows the idle speed cable connection?

 

[John OoSTerhuis]

Hello ___, fellow Iowan,

Here's pic from my AudioVox CC install.



It's the cable that comes in from the bottom right of the throttle bellcrank.

Here's another one of the back of the carbs removed from the ST:



Clicking on either of the pics will take you to the original on the web where you can then click on the 'full size' icon for a closer look. HTH

Regards, John

 

[93NJST]

I took mine off and it had a spring on it. Shot across the garage and that was the last I saw of it. Lucky for me I had a new set of carbs for the bike that had the adjust screw in it. However, looking at the carbs it did not look too easy to get to the screw while it was in the bike. But I'm not a mechanic.

Good luck,
Adam

 

[SThelper]

Hello ___, fellow Iowan,

Here's pic from my AudioVox CC install...

Regards, John

Thanks John, I'll have my dad look at these and see if they help him.

-Mike

 

[John OoSTerhuis]

Hi Mike,

The idle adjust is a pretty simple arrangement. The threaded tip of the idle adjust cable passes through a tensioning spring and then screws into a through-hole on a boss on the back of the carb body. The ST1100's throttle bellcrank has a tab projecting out at about the 2 o'clock position that rests on the tip of the cable. Depending on how far you screw the cable end out the other side of the boss controls how far the throttle bell crank can return when you let go of the throttle grip and the spring on the bellcrank rotates it back (clockwise in the pics above) to idle -- sets the idle speed.

With the top shelter off you should be able to see if the idle adjust cable is no longer attached. Come to think of it, just grab the other end and pull. If it is in fact unscrewed, you should have the whole shebang in your hand. Well... except for the pesky little spring which will undoubtably lose itself somewheres down into the black hole of oblivion where all dropped parts go.

Where are you located in Iowa, Mike? I'm on the 'East CoaST' in the greater megopolis of the Quad Cities overlooking the Big Muddy. I've been known to ride quite a ways for a bite to eat.

Regards, John

 

[SThelper]

John,

I talked to my dad last night, sounds like the idle speed adjuster is still threaded into the carb, but it's hard to be sure. The bike sat for a while this winter and the first ride of the spring was a bit rough. The engine ran poorly at low RPM and wouldn't idle without adding choke / throttle. Dad fiddled with the idle speed knob and also sprayed some Seafoam into the carbs. Now the bike runs better at low speed but still won't idle. I'm trying to figure out if he backed the idle speed adjuster out too far or the idle jets are still gummed up.

As for me I live in Iowa City and work in Cedar Rapids. My wife works for the university, we moved here in '03. I have an '07 CBR1000RR that I commute to work on when the weather's good. I really like getting 40 MPG these days...

Later,

Mike

 

[George]

Mike, sounds like clogged lowspeed jets to me. Idle is nearly non-existant and runs ruff besides. To fix, ya gotta pull the carbs, pull'em apart, and mechanically clean the jets. If completely plugged, the cleaner won't work because it never gets to where it's needed.

I've done this job several times over the past 15 years. Hard to keep all three bikes clean. While one is running, the other two are gumming up.

 

[John OoSTerhuis]

John,

I live in Iowa City

Less than an hour away, Mike. PM sent.

John