cold idle sidestand issue

Carbs have been completely rebuilt cleaned and renewed. Valve clearances are in spec. Wet set the floats to spec. Bike has been vacuumed synced and carbs have been colortuned. Runs great.

But, and this isn't a real problem, but when overnight cold, if I start the bike with or without the choke , it will run fine until I lean it over on the sidestand. If it is idling without the choke, it will sputter then stall, if I have the choke on, the idle will decrease from 2200 rpm to 800. As soon as I stand the bike straight up and blip the throttle, not problem....

Is this a float problem?

 

It could be interesting to know if it stalls from starving on #3 and #4 or from flooding on #1 abd #2 cylinders. Plugs wet or dry when it happens?

 

great question,,,will let you know the next time I go to take her out. Thanks

 

I would say starving, since it runs better when you put the "choke", but let's see what you find out.

 

IF you set the floats back to factory spec... I would guess it's flooding.
I always set any "older" carburetor floats 1/32" lower than spec.
Gas today just isn't as dense as in the 1980's. This is due to the ethanol content. So, to get the same level of fuel in the bowls, you have to reset the floats slightly lower.

Ray

 

FYI. It only does this after she has sat overnight. The rest of the day, I can start her while sitting on her side stand and she idles at 1050 rpms with no problem. Blip the throttle and no hesitation.. I also run ethanol free gas.

 

Try putting the petcock on "PRI" for about 30 sec before starting it and see if the symptom persists.

 

Will give that a try in the morning. Right now the heat index here is 110 degrees. I took the temp of my wood deck on the back of the house with the laser thermometer and it read 157 degrees. The ground in the sun bounces between 105 to 110. The ac vent in the house is pushing cold air at 54 degrees and the beer in the fridge is at 38 degrees.

I am not going outside until tomorrow am...lol

 

All of which lends credibility to my (unstated) theory as to the cause...

If putting it on PRI ahead of trying to start it solves it, then I probably nailed it...

 

what be that secret unstated theory ya got there Fitz...

 

I might be wrong but I think he is saying that 38 degrees may be too cold for a 'premium' beer. If you got Blatz, Miller, Bud, PBR, etc. then you are ok; anything else should be a tad over 40 degrees F.

 

From one Bruce to another, what, exactly, is "overnight cold"--- in Florida???

 

that would be the dreaded...

EVAPORATIVE emissions.

I wonder if your #4 carb is boiling itself dry sitting in the sun; or if not dry, at least down some. Enough for it to take a few minutes to completely fill back up with the motor running.

Quite possibly all of them, but #4 and probably #3 for sure.

Heck, my bike needs "PRI" for a bit if it hasn't run in a week; and I keep it in my garage, in Michigan (where it is currently 54 degrees F.)

Try PRI and let's see...

 

Went out just a few minutes ago. Turned the fuel to PRI and waited 30 seconds, turned to back to ON. 3/4 choke, push the button and she started right up.

So you all understand, the bike sits under a large carport in the shade, out of the weather sort of. When I start the bike in the morning I am on it holding it upright and let it "warm up" for about a minute then ride it to the front gate, which is about 150'. That is where I have to put the bike on the sidestand and it would have it's idling issue.

This am, following Fitz's advice I repeated everything I normally do.

Got to the gate, put the bike on the side stand and there was none, zero change in the rpm's and idle sound.

Thanks Fitz and all the others....

It was to soon to go back into carburetors...

Now, back to important stuff, the beer is just plain old Bud Light in a can. Even in a insulated coozie, the beer will warm quickly. I personally have a 4 minute rule to a 12 oz can, so I won't have to drink warm beer.

Overnight cold refers to when the outside air temperature is equal to or less than the inside air conditioning setting. We keep ours at 78 during the day.
Drop it to 74 at night. Here in North Florida we had a week of below 20 degrees last winter. Lost some really nice plants, but just gives a chance to grow new ones.

But I guess anywhere in the continent there is 3 months where you only go outside if you have to. Here it is July, August and September. Where I grew up in upstate New York, it was December, January and February. I don't miss the snow, ice and mush..

 

So putting the petcook on Prime was the cure?

 

Remarkably it does seem that way. Something Fitz referred to as Evaporative Emissions. The problem only showed up in the last couple of months. As coincidence that is when it got into the 90's every day. Hopefully Fitz will chime in and give us a better explanation.
Did pull the plugs and all are normal and the same.
Guess it is a matter of doing the same start up procedure every day to see if it actually corrects the cold idle on side stand issue.