Topic: idles at 5000 rpm

[Burnboy]

I have a '75 cb750, running pods and 4-4 exhaust, just rejetted to 130's, just set valve clearance, timing is spot on. To start it I have to use full choke. it idles ok, kinda rough but it idles at about 1700. If i let the choke off the idle climbs to 5k. what the hell is wrong with it?

[Burnboy]

also the idle screws are 2.5 turns out

[MotoMartin]

This may be another one of those which position is the choke on issues. The choke is on when the knob is pulled up and off when pushed down. We have had a couple of people having that the wrong way around lately.
If that is not it, you may need to adjust the idle with knob on the right side of the carb.
Or it could be an air leak, check all the carb boots.
Those are not idle screws, at the front of the carb underneath, they are fuel air mixture screws, do not use them to set the idle.

[Burnboy]

i see, then when the choke is on, lever pushed down, it revs to the sky. checking for boot leaks now

[MotoMartin]

Nope, the choke is off when the lever(knob) is pushed down.

[Alan F.]

Have you visually set float height with a tube?  That seems to be a popular issue lately.
Floats in upside down? Or a float that doesn't float?
Carb slides in backwards is another popular one.
130 is a few steps higher than stock, maybe that's it?
What size are the slow jets?
And lastly the tiny holes in the sides of the emulsion tubes are clean?  They seem to be the biggest cause of a consistently high idle lately.
Just stabbing in the dark with the popular issues, I'll be struggling with mine personally in about a month if all goes well.

Just like my 750K3, the choke in active when the lever at the left of the carb rack is up, when it's folded down it's inactive. 
On and Off seem to confuse lots of us when it comes to chokes.
Good luck.
-A

[Spanner 1]

+1 with Alan......also flooding fuel in the carb throat ( stuck float valve ) will cause the motor to rev it's head off with the slides all the way down!

[BlackMax]

I'd bet $1 it's the throttle cable.  Have you adjusted any of the bends recently?  I mine once idled at 4k plus, and I went nuts for a couple hours trying to figure it out.   Loosened the main elbow and allowed it to swivel a bit, then tightened the lock nut back down.....problem solved. 

Your throttle should have 1/8" of play or slack.  In other words, you should be able to twist it a little bit before it engages the throttle. If it's tight at all times, there's your problem.