Starting in Cold Weather

Can you start your motorized bike in cold weather?

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Hi, I'm a rider from Tucson and I'm having some trouble starting a 48cc 2-stroke in cold weather (this is my first winter with a bike), which is ironic considering that the average temp here is about 65F in December.

So, basically my bike rides/starts fine during the day, but after sunset when the temp is below 60F I can't start my bike. Playing with the clutch, choke, and throttle does nothing. It will start for a moment but then cuts out. Even force pedaling the engine to turn over and warm up (so the manifold is warm to the touch and my legs are pounding) doesn't help, it just putters like the thing is out of gas (and it has a full tank).

I surmise that it might be my gas is too cold. The bike will run for about 10 seconds at first (the gas already in the carb) but after new gas funnels in the engine stops. What I'm wondering is if anyone else has had trouble starting a motr'd-bike cold in relatively cold weather. Should I look to get insulation on my gas line? Is there something like anti-freeze for 2-strokes that I should use? Or do I just have to take a blow dryer to my gas line to start the thing up?

I know its not a problem with the gas mixture since I'm able to ride the bike for 4+ miles during the day and it runs normally (besides my rattling fenders), but coming home at night (just after sunset) the engine just won't start. Any thoughts?
Sounds like it's the dark of night that it does not like, not the temperature! :LOL:

Just kidding...the temperatures you are talking about will have nothing to do with fuel flow, so don't worry about that. The only thing that really has anything to do with it is mixture. I know you don't want to hear it...probably don't want to deal with it, but I'd richen the mixture at least one notch on the needle, maybe two, and see what happens.
Hi, I've ridden in a lot of cold weather (below freezing) and never had a problem. I start out with full choke, lever up, then when it starts I gradually move the lever down. Usually 1/2 choke for 2-4 blocks then lever down and ride normal.
Maybe it's not the cold......your bike might be afraid of the dark? haha
just kidding.....I'm sure some of the guys here will have some insight on your problem. good luck
By richen the mixture do you mean put in more oil? I usually use about a 30:1 ratio and the tank currently has fully-synthetic 2-stroke. Would putting in a more concentrated ratio help the engine run smoother?

So, After extensive testing (down my street and back ...) I've concluded that the engine is prone to failure just as much in the heat of the day as at night - yea, it cut out again. So this time I drained the tank and replaced the gas and it runs fine.

I didn't ride the bike for about 3 weeks and the gas sat in the tank the whole time, maybe that was the problem ... I guess I'll just have to make sure to ride the bike every day. Now to see if I can ride it at night ...
No, by richening the mixture, we mean richen the carb (fuel to air ratio), but it sounds like you've found the problem. Teoretically, the engine needs a richer fuel to air ratio when it's cold, or when the air is colder because the air is denser (higher oxigen content) when it is colder.

It is good practice to store your fuel in a sealed container mixed, and only put the amount of fuel in the tank you think you will use in a short period of time. By doing that, the fuel stays fresh longer. The trick is to estimate the amount you need accurately, and not run out. :LOL:
One of my GEBE engines hadn't been cranked in a long time, and a sure fire way to get it to start on an icy day was to take off the black cover, and pour a smidgeon of gas right into the screen.

Two pulls and "vrooooom". :eek:


Make that "vreeeeem". ;)

what part of town are u from.
sometimes i have the same trouble i just put the choke all the way up then prime the carb a little then ride till it fires then while riding slowly put it back down till the motor runs smoothly.
I dont even need to hit the choke.

If I drop the clutch, i skid a little usually, but to overcome that, i just keep pedaling as i drop the clutch
welcome to the forum, quadanar :)

my bike stays inside, but i still have to choke it to get it fired-up...about 30-45 seconds of that & i'm off and running 8)
Mr. Quad,

Your second post holds part of the answer. The better a person breaks in the engine, after a certain point the engine is going to "kick in" or "surge", on these 25 cc engines at about 150 or so miles.

More use makes easier operation, AS LONG AS THERE IS OIL IN THE GAS.

The mixture you end up with will affect "carbon buildup" at a certain point.

But at around 1,000 miles or so, these 25 cc. have "seated into the cylinder", and optimum performance commences.

SUPPOSEDLY, there is a simple grinded screwdriver tool that could be carried along in a tool kit for scraping out that carbon, BUT I HAVEN'T SEEN A PICTURE OF ONE......hint hint..... ;)

BTW: did anybody hear "CarTalk" on NPR yesterday, where they were talking about 2 cylinder engines running the earliest airplanes after Kitty Hawk?

They used Castor Oil, and the reason they wore long long white scarves was to "filter the fumes that blew in their faces", causing bowel emergencies for the "scarfless" pilots. :p