Will not start in cold

[Bk834]

Went to go for a ride today on Lucile, around 44* F outside, and once again she will not start in the cold. This is the 5th time she has failed to start in the cold. Above 60* F and she cranks right up first try. No full or partial choke position helps. I'm a fuel injection man, so I'm not the best with carbs, but I did rebuild and clean this one fully, and had it starting and running perfectly everytime Ive rode it, when it was above 60*. It never even needed the choke to be able to start or warm up properly afterward the rebuild. Where should I start to look for the problem here?

[CC Cowboy]

You have a Florida bike! It happens whenever the temps are below 60 on all Florida bikes. Just wait until spring and you'll be fine.

[jkv45]

Have you gassed-up lately?

I believe they will change the gas blend in your area for the seasons, and if you have a summer-blend gas it will not vaporize in cold temps.

I would try full choke (enrichener) and opening the throttle slightly as you are cranking.

Carbs need adjustments for cold temps, so the idle mixture may be off and need to be richer.

Gas without ethanol will also give a richer mixture than gas with ethanol in a carbed engine.

[Triple Jim]

Man, that reminds me of the time I filled up a motorhome in the north winter, and drove to Florida. I had a rough time getting back up route 95 because of all the vapor lock I experienced from the winter gas blend in the hot weather of FL. This is the exact opposite problem, of course.

[taz]

Are completely for sure that the choke cable is hooked up and operating correctly?

[Bk834]

It was probably October the last time I gassed her up. Good call. I hadent even considered that it might be the blend of gas. That makes the most sense. My choke does operate correctly, I verified that before I posted. I was thinking before that it might have been a slightly clogged passage in the choke circuit or something. Summer blend gas not vaporizing properly in low temps makes the most sense though. Coming from all fuel injection vehicles, I'm not use to having to consider the gas anywhere near as much.

[jkv45]

Originally Posted by Bk834

It was probably October the last time I gassed her up. Good call. I hadent even considered that it might be the blend of gas. That makes the most sense. My choke does operate correctly, I verified that before I posted. I was thinking before that it might have been a slightly clogged passage in the choke circuit or something. Summer blend gas not vaporizing properly in low temps makes the most sense though. Coming from all fuel injection vehicles, I'm not use to having to consider the gas anywhere near as much.

Hopefully it's as simple as that.

I would probably drain the tank completely, just in case their is any condensation that has formed from the changing temps.

Keeping the tank as full as possible helps reduce the chances of condensation forming, and ethanol-free gas lasts longer (among other advantages).

[SLOWn60]

How many turns out did you set your idle screws? There are little metal caps pressed in place at the factory to prevent adjustment of the idle mixture. They need to be drilled out to adjust the screws. Did you notice if those caps were removed when you cleaned your carbs? If they are still in place, the idle circuits will not have been cleaned and may still be clogged. You said you never had to use your choke above 60* so assuming your choke cable is operating: my money is on too lean an idle circuit setting either from them being clogged and/or set too lean. These motors seem cold blooded compared to many and come from the factory set very lean to meet emission standards. They almost always need a little or a lot of choke no matter the weather and your starter motor will thank you if you set the idle circuits a little richer! I'm having a brain fart and can't remember if it's 2.5 or 3.5 turns out for a decent mixture! Someone will pipe up soon with the info if I don't find it first!

[jkv45]

Originally Posted by SLOWn60

How many turns out did you set your idle screws? There are little metal caps pressed in place at the factory to prevent adjustment of the idle mixture. They need to be drilled out to adjust the screws. Did you notice if those caps were removed when you cleaned your carbs? If they are still in place, the idle circuits will not have been cleaned and may still be clogged. You said you never had to use your choke above 60* so assuming your choke cable is operating: my money is on too lean an idle circuit setting either from them being clogged and/or set too lean. These motors seem cold blooded compared to many and come from the factory set very lean to meet emission standards. They almost always need a little or a lot of choke no matter the weather and your starter motor will thank you if you set the idle circuits a little richer! I'm having a brain fart and can't remember if it's 2.5 or 3.5 turns out for a decent mixture! Someone will pipe up soon with the info if I don't find it first!

Right.

2.5 is the normal starting point. Maybe close to 3 in cold temps with ethanol gas.