[Snobrd]

1285 miles on my '07 Iron Bullet Classic.  It has been running wonderfully well.  Running smoother with every mile.  It starts on the 1st or 2nd kick most of the time.  More than 3 is most likely me not the machine.

About 3 weeks ago I noticed I was having to adjust the idle fairly frequently.  Then when warming up, and it had never done it before, it would suddenly quit.  Just running fine...dead.  Then starts right up 1st kick and continues normal warm up.  It was doing that fairly consistantly on first morning start up.  Now the throttle acts as if sticky.  The cable doesn't seem to be sticking but it takes 2 or 3 seconds to go to idle after rotating handgrip full off.  Wednesday morning it was 30 degrees hard frost everywhere.  The bike is stored in garage so no problem at all on start.  But during warm up idle it momentarily stopped dead for a fraction of a second then as if the flywheel carried it through the stroke (but just barely) it then ran normally.  It did it a second time then and since not again.  The delay to idle while riding is still happening and maybe getting worse. 

Ideas regarding diagnosis and recommendations for fix would be greatly appreciated.  Many thanks.

[The Garbone]

When I first got my machine I had a similar problem a few times around the same mileage as well.   I would kick her to life, come to a stop a mile or so down the road and she would just die, would only run if giving throttle.  I discovered I was leaving my enrichment lever down on the carb,  never use that thing any more. 

Also, I adjusted my idle a bit higher than I thought was right.  Guy I work with told me its a Thumper not a V-twin, it needs to idle a bit higher than a Harley.  So now it idles OK cold but around 800 (a guess) when warm. 

I would hit the movable parts/ cables with some WD-40 or some CRC type lube to displace any moisture,  won't hurt anything.

[Chasfield]

Is the carb slide actually hitting the stop when the throttle is closed? It might be just hanging on the cable if there is insufficient free play in it. This would give an imprecise closed position and inconsistent idling.

And/or the slide is sticking a bit on its way down. Removing the carb and pulling the slide out should reveal that part of the problem.

I must say, I never have trusted my Classic to idle by itself and I tend to blip or fast idle it at the lights. It likes to catch me out with a hiccup and stalled motor if my mind wanders..

[Snobrd]

Chasfield,  I'm glad to hear someone else has to think about the possiblility of a stall at stop lights.  The only time I'm ever tempted to use the electric starter is right there when you are first in line at a light and it does the little hiccup to dead thing.  You can feel all the eyes on your back.

Re: The slide.  I was kinda thinking it might be a sluggish slide.  I haven't gotten in to the carb yet.  Gary, I will try the WD-40 thing first but I think it's about time to learn something more than lubrication.  Thanks.

[Chasfield]

The hiccup and stall thing is weird. My bike spits back a bit when cold then seems ok after a mile or two. But once it is fully warmed up the tendency to cough and stall seems to return. My plug tells me that if anything I am running a bit rich at small throttle openings - standard wisdom is that weak mixture causes the spitting back. I up-jetted for the after-market exhaust that is fitted but the air filter is standard.

I am starting to suspect an air leak - my idle screw is only out three-quarters of a turn and that is with a 27.5 pilot jet installed. The front rubber (head to carb) is new but the rear rubber (carb to chrome air box) I have doubts about and think may be porous.

[baird4444]

an easy test to see if the cable or slide is binding is to twist the throttle and release when not running. You should hear the thunk of the slide coming to rest on the stop.
The most common place for the cable to bind is at the top of the carby where it has to make that hard 90 degree turn at the gas tank.

The hiccup could be that your timing needs just a little advance...   have your points closed up any??   If so; this is retarding the timing. Just reset points...
                 - Mike

[Snobrd]

Thanks for the lead Mike.  I just ran downstairs to check for slide thunk.  Very positive thunk with no hesitation at all.  Slide and cable would seem not to be the cause for the downward delay.  Could the freedom of the slide be affected by temp?  I just tested a dead cold engine.  I won't be able test it hot until tomorrow afternoon.  I'll also take a look at the points.  Timing kind of makes sense with the odd dieing at idle with the immediate self restart a fraction of second later. 

[dewjantim]

Check your spark plug, it may be sooted up.......happy thumpin'.....Dewey.

[Bankerdanny]

Chas is on to something with the air leak.

spray the wd40 around the carb connections as see if it evens out. If it does you have a leak.

[Snobrd]

Do you mean spraying the ends of the rubber hoses or all of the hose?  Not quite sure what you mean by evening out.  I did a cold hot test yesterday.  The problem seems to occur only when hot.

[1Blackwolf1]

Do you mean spraying the ends of the rubber hoses or all of the hose?  Not quite sure what you mean by evening out.  I did a cold hot test yesterday.  The problem seems to occur only when hot.

He means spraying the area around the hose where it meets the carb, if you have an increase or stabilizing in idle that would mean you have an air leak around the intake hose.  You could try tightening the clamps on the intake boot from the carb anyway.  My mount bolts for the carb intake horn were loose at the carb and it was doing something similiar to yours..maybe not quite as erratic.  Hope this helps.  Will.

[sopwithdriver]

Have you tore down the carb and cleaned it lately? It may just be a speck of junk that is giving you fits. FWIW. Its snowing today here. Time to winterize the 1/2 ton.

[Snobrd]

Thanks for the clarification Blackwolf.  I will give that a try.  Re: tearing down the carb... haven't done it yet but it's next.  I didn't think the carb would need it at just under 1,300 miles.  But you're right, could be just a spec of something. 

Cool but beautiful day here today.  The REB makes going to work such an incredible pleasure.  Got a few miles in at lunch and there is always the long way home even if dark.  Got to get me some clear lens goggles with it getting dark by home commute time or just give up and go back to the full face.  Got too used to the Porridge Pot and goggles this summer.

[sopwithdriver]

I just thought of something else. Have you had the fuel tank off lately? I find that when I take the tank off I have to fiddle with the throttle cable where it comes out from under the tank to the carb cap. sometimes it can get pinched and is not allowed to float in the carb cap there by causing that delayed idle thing when you let off the throttle. Doesnt take too much binding up there to do that and if its happening and you adjust your idle screw with it binding you'll be chasing your tail for a setting. there is supposed to be a few mm of play in the carb cap to allow for the housing to float and not affect your setting.  the carb cleaning only takes 15 minutes to do and eliminates that as a source. who knows what crap you get in fuel everytime you fill up not to mention the crap that comes out of the tank occassionally. who knows at 1500 miles you may have enough dirt in there to plant taters. When you eliminate all of these variables then check for your air leak. Put a filter on if you havent already as well. Roger.

[Chasfield]

Good point about the throttle cable run under the tank. The last turn in to the carb is very tight because under-tank clearance is small. I taped my cable end in place to prevent an air leak and to stop the ferrule popping up and sideways out of its socket under the slightest provocation.