Way high RPM after removing airbox

Need some suggestions.

I pulled the airbag off to add in a Rosta cruise.
Reassembled the airbox after double checking all the linkage moves freely.

Start bike, idle sounds high and climbing. Settles in around 4500
After a few minutes it starts dropping as the engine warms. Once I'm at 3 bars the idle speed is down to 2500.

So what the heckler is going on.

What I do know:
Wax cylinder is operating properly.
Antifreeze is good and topped off.
Set idle screw is backed all the way out. Screw it in a bit and engine rpm climbs.
I reattached 3 houses to gas tank.
2 vacuum hoses attached under airbox.
Throttle moves cleanly, butterflies are closing.

Killed and restarted bike, same thing happens.
Let bike cool down completely and the same routine occurs.
Blipping throttle just does what it should.

Did I forget a wire somewhere?
Oh... I checked 5way while in there and clean.

Any help appreciated, especially if it saves me from totally removing the tank.

Thanks,
T

T_C said:

I pulled the airbag off to add in a Rosta cruise.
Reassembled the airbox after double checking all the linkage moves freely.

Click to expand...

My money would be on some part of the air box interfering with the throttle linkage.

A quick way to check that might be to open the air box, put a finger on the bottom, open the throttle and let it snap shut. If you feel a thud, something's holding the throttle open.

--Mark

Blrfl said:

My money would be on some part of the air box interfering with the throttle linkage.

A quick way to check that might be to open the air box, put a finger on the bottom, open the throttle and let it snap shut. If you feel a thud, something's holding the throttle open.

--Mark

Click to expand...

Well the trthrottle feels like it is closing. But obviously something under the tank is the problem.

Lifted the tank just enough to get airbox lid off. Then pulled the front right snorkel tube.

Closed, dang it... going to see if I can pull the rest of the airbox without removing the tank.

Any other suggestions appreciated.
T

Any way you can start the bike with the throttle plates in a known closed position ?

That could point to , or eliminate a vacuum leak of un-metered air

v8-7 said:

Any way you can start the bike with the throttle plates in a known closed position ?
That could point to , or eliminate a vacuum leak of un-metered air

Click to expand...

Pulled airbox with tank hoses still connected. Yeah! Didn't know you could.

Butterflies are all closed.


But the small holes for the idle bypass air are wide open. Great! Found out why the idle is so fast. Now what the heck is causing that?

T_C said:

But the small holes for the idle bypass air are wide open. Great! Found out why the idle is so fast. Now what the heck is causing that?

Click to expand...

Okay. Of course the idle bypass holes were open. I hadn't warmed up the engine to get them to close yet.

Cruise control cable too tight?

Remove the aftermarket cruise control...
I've seen more than a few of these cause your RPM issues, could be a defective unit, air leak, installed incorrectly etc.
I'd start over, remove the unit and see if it works normal again.
Igofar

If I remember correctly the Rosta requires a RPM reducer to work properly, was one installed on the tach signal wire? If so was it set correctly, double check.

Byron said:

If I remember correctly the Rosta requires a RPM reducer to work properly, was one installed on the tach signal wire? If so was it set correctly, double check.

Click to expand...

Not even in Rosta testing/use mode yet. Just firing up the bike after dismantling it for Rosta installation.

If you followed the instructions listed here then my guess would be something pulling on the throttle cable. The vent hose that runs under the front duct of the air box may be the culprit if it didn't get fitted into the part that holds it up.

zooker13 said:

Cruise control cable too tight?

Click to expand...

Igofar said:

Remove the aftermarket cruise control...

Click to expand...

Ding Ding Ding

The cruise cable was just a hair on a gnats ads tight.
You know it only takes a 1% throttle opening to get a few thousand RPM out of an engine with no load on it.