Topic: No vac leaks, but takes time to reach set idle speed

[evanphi]

My intakes have no leaks. I took a propane torch (unlit!) to the intakes and no increase in idle was found. However, my bike still idles at around 7-800 when I first start it and will die if I don't keep the revs up. After about 3 minutes of holding at 2.5K, she is warmed up and sits nicely at 1000RPM where I set it, and doesn't get any higher than that. Idles nice and smooth then.

Thoughts on the "cold blooded"-ness?

[nevernoluck]

Adjust your idle? What bike you have? I have to adjust my idle up a little when warming bike up then after it gets good an warm back down, probably not right but I can reach right down on my 650 while I'm riding and get it done

[flybox1]

Unless you have the benefit of pd carb fast idle cams, you need to turn in your idle set screw to hold idle at 1500-2000, then turn it down as you get to op temps....

[Bootlegger56]

If cold I crank with full choke, cut it back to about half take off and ride for the length of my development road about 1/2 mile.  Start out on the highway and bump the choke off about mid ways through third gear and I am good to go.  I never mess with my idle adjustment screw.  Doing a carb sync, thoroughly cleaning the low speed jets including the atomization holes, adding a HM transistorized ignition, dyna coils and using ND X24ES-U spark plugs along with a K2 advance unit and proper valve, timing and points adjustment have all but eliminated the worst of the cold blooded nature.  Having said that these bikes tend to be a little cold natured but for us old folks who grew up using a manual choke on our cars its just second nature. 

[bjbuchanan]

Don't screw with the idle knob, leave it how it is supposed to be set at when you have a warm engine. No fast idle cam means you gotta pay a little attention to the bike when warming up

Are you using your choke? Even if it is 90 degrees out it doesn't mean your engine is warm just because you are. Try full choke and see if it stumbles and dies with no attention. This 90+ weather in NY has seen me using like 3/4 choke on startup and adjusting down faster than cold weather. It isn't cold bloodedness, it is a cold engine. From your description it seems like you are doing what I described, full on and dead or off and racing rpm. You gotta work the choke, it has a range

[kghost]

I have a 350F, a 400, a 550 and 6 750's.

They are all cold blooded.

I generally on a warm day do not have to use choke....but every one will die if not allowed to warm up.

As you said....idle around 600-800 dead cold, increasing to 1000-1200 warm. Every one of them

[evanphi]

OK sounds good folks. This is my first time riding an old bike. I start full choke (starts first kick) , then back off immediately to about 1/2 or full open while keeping the throttle open a bit. This always works for me, I just didn't know if it was "normal" or not.

I would never be messing with my throttle stop screw... I can't adjust it by hand without taking off my tank! 

[kghost]

They may be referring to the one on the grip.....

There was a small knob under the right switch that could lock the throttle.

[trueblue]

Tim, the later bikes had a knob on the right side of the carb rack between carbs 3 & 4 to adjust idle speed

[kghost]

Tim, the later bikes had a knob on the right side of the carb rack between carbs 3 & 4 to adjust idle speed

Yeah.  Well aware of that. Most of the 750's without the 4 individual cables lol

I'm prolly one of the few that still have the throttle set screw on both my K2s lol

[evanphi]

They may be referring to the one on the grip.....

There was a small knob under the right switch that could lock the throttle.

My controls have a hole for this "cruise control" knob, but no screw in it. I don't need it.

[evanphi]

Tim, the later bikes had a knob on the right side of the carb rack between carbs 3 & 4 to adjust idle speed

Mine is on the left (1975), and impossible to get to without removing the tank. Should it be on the right?