[jonapplegate]

Hello all. My idles doing interesting things. Bikes been great but one day Idle just way way too high. kept turning idle down as I rode 'til somewhat normal.  Don't think the cable or slide is sticking. Next morning, fired her up and the idle was too low. Had to move it back up. The day it was racing the Temp. got to 90f. Could it be from tank pressure building up? Or something else?

[BanditRE]

Could your automatic advance weights/spring be stuck (in the distributor)? Mine did this for a while when it was new. When I came to a stop after riding it would idle high, so I'd let the clutch out with it in gear and slow the engine down. If it stays down after that, it may be your advance weights. They're on springs that are supposed to return the weights to  the center as you slow down, but sometimes.......they don't.

[scoTTy]

do yoou have that smog thing on your bike..  soorry i forget what they call it and so many are takining it off..   .. cheap rubber hose,,, on mine keeps splitting and then the engine races.. check it out...   I'm about ready to plug it since I'm running out of tubing

[Kevin Mahoney]

You are getting good advice here. One thing to keep in mind is that the iron barrel Bullets idle slower when cold than when hot. This is why the idel speed screw is a large thumb screw and is easy to get to. Beyond that the advice given about the advance weights is valid and also very CAREFULLY check the intake hose between the carb and the head. Lastly make sure that your throttle cable is not getting hung up at the top of the carburetor.

[LotusSevenMan]

With a gloved hand I found this tickover screw tricky to alter on the move so JB WELDed a washer in place now to make it v. easy!!! 

[jonapplegate]

That welded washer is cool! Haven't checked PAV, I think scotty was talking about this. I will. Don't think anything is hanging up. Have recently checked rubber intake thoroughly. I know that "micro cracks" in rubber, while not significant sources of vacuum leaks individually, taken as a whole can create quite the vacuum leak. This is why it's a good idea to replace every vacuum line on an older car before you tune it for the first time. Even if most lines seem good, there are probably enough "micro cracks" to add a significant vacuum loss. Back to bikes. Same thing. Yesterday, had to turn down the idle. Now it was Idling to fast. Fired her up this morning, not enough idle, turned it up 'til it wouldn't die and just a smidge more. When I turn down idle because it's high, it's not like I am turning down until it barely keeps running. When it's been racing I 've been turning it down to where it isn't dangerous in low gear anymore. Still running higher than optimum. I am probably imagining but it seems to coincide with the big temp. swings we have been having.  That said fiddling with the idle? I could have worse problems. It otherwise is a pleasure. 

[BanditRE]

With a gloved hand I found this tickover screw tricky to alter on the move so JB WELDed a washer in place now to make it v. easy!!! 

Nice and simple. Like it!

[cyrusb]

Have you peaked your carb lately? I went to the rich side recently (clockwise for less air). After that ,peak the timing for fastest stable idle, then adjust the throttle stop screw for idle. Of course this is done while running with properly adjusted points.Try it you'll like it. It did not give me the exact same idle for both temps, but they are close enough.

[jonapplegate]

I am going to be adjusting the points and valves very soon. That said, the bike starts great, runs great. Could not be happier. Need to go and have some one take a look at the brakes and adjust as necessary. Everything has gotten better, except the brakes have gotten worse, understandable!

[LotusSevenMan]

Forgot to say I used a washer rather than a flat plate so that there was less air resistance.................................. Errr, OK, that's not quite true 

[cyrusb]

I wonder how many other bikes have a situation where the idle has to be regularly adjusted ?

[Thumper]

My Urals had two annual idle speed settings. When the warm weather arrived I'd have to adjust the idle speed down, because it would start to creep up. At some stop lights it would rev up quite a bit - to the point that I'd slip the clutch (at a stop) to draw it back down.  When the cold weather arrived I'd have to do the opposite because it would threaten to quit at stops (due to the slow idle speed). (After the seasonal adjustments this would not happen anymore).

However, it wasn't so cut and dry to diagnose this and come up with the simple seasonal adjustment....

What happened was that the idle seemed unadjustable, almost erratic.

When I adjusted for a cold idle, it would over rev when warm. When I adjusted it with the engine hot because it was revving up at the stoplight, it would threaten to quit when cold or warm the next morning.

What I determined is that the Ural carb was adjusted very lean (as most carbs are now) and was on the outside edge of the adjustment spectrum. Every input to the idle mixture and idle speed had an impact. Additionaly, I had to make sure that there were no air leaks in the intake tract. (During the process I also lubed the throttle cables and made sure they weren't binding).

I resolved the issue (at least to the point of having two seasonal adjustments to the idle speed) by first adjusting the idle mixture correctly. Then I carefully  adjusted the idle speed in the smallest increments to get it spot on. There was a very narrow sweet spot where it would idle just fast enough cold and just slow enough warm/hot that would work. Less than 1/16th turn on the idle speed adjustment screw would throw it off.

Yours might have a similar issue.

Matt

[jonapplegate]

Thanks for all the advice. I will take it. Everythings been fine again, idle wise, and it starts on 1 kick as usual. Curious to see what, if anything, happens when the temps get warm again.