Motorbike Won't Start in Cold Weather - not battery?

I have a Honda Magna 250VTC 1994 model.  Temperature drops to around 5c, and the bike refuses to start (and roll-start is hesitant down the hill).  Temperature at around 15-20c and it starts no problem.  It's not the battery (it's perfect), or spark plugs (new & even narrowed gap a bit - didn't make any difference).  And yes, I've tried choke on it.  It doesn't even want to start in cold weather.

I had been thinking starter motor, but that surely wouldn't be affected by the cold like this.

13 Answers

  • 1 month ago

    change the oil to a lighter grade , 10-30 grade..if the bateery is new then it should start.

  • The flash point of petrol is −43 °C so it's either electrical or mechanical.

  • Anonymous
    1 month ago

    Check air cleaner and see if you can see sunlight through it or it is blacker than night) If not the problem then

    Bike shop as soon as you can.  I won't fuuck with a bike that gives me problems.  This should not be a problem. 5C is a cool morning. BFD! If anything, with the choke ON fully it should bang off and YOU ARE GONE.  It is choke related or a very dirty aircleaner.   Let the bike shop guys fix it for it may be something else.  (Like you been using WATER for fuel)  More likely the carb(it still has that, right?) is mounted loose. Let them find & fix it. Maybe your bike has been recalled because it is a PoS? 


    Just thought of another thing about HONDA.   Check your oil level. If it is too low. the bike WILL SHUT DOWN.  Where ever it is right now it is on the MARGIN.  When it is warm liquids expand(including oil) so it is full by a cunnt hair.  When it is cold it shrinks like "mr Winky". So you are not measuring the oil level correctly or ever checking to see if there is any oil in the bike. (I do that with every ride.) I knew if I yabber long enough "SOMETHING MAY POP IN MY MIND" & IT DID from stationary Honda motors like pressure washers & lawn mowers.

    This is to prevent you from seizing up the motor with the lack of lubrication. Spend a buck for half a quart of oil or $5500.00 for a new bike?

    Your choice. To be smart(& rich for beer) or dumb& poor. 

    Read your manual and fill the bike correctly. Obviously you are not doing that.  Yes, all engines burn some oil. But even a tiny bit every ride and you ride 100 times adds up to oil missing.  On my bike it was 20W50 oil as it has a wet clutch.  Use what the book recommends not what the gas station has on hand. It is the wrong oil as it is for cars.

  • Fred
    Lv 5
    1 month ago

    On the cheap: Get a heat lamp, place it near the motor, try to start it after 20 minutes or so.  This will work in a closed garage, if out side add a blanket to keep the wind off of it... and be very careful not to catch the blanket on fire!

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  • fuzzy
    Lv 6
    1 month ago

    Is it carburetted? If so float level may be off. An error of 0,5 mm is enough. Get manual & check it carefully.

    Could also be weak spark; cold weather battery cranking ability drops, reducing out put voltage which can affect spark strength.

  • Anonymous
    1 month ago

    The starter motor would be affected if the battery was particularly cold (all chemical processes, like those in a battery, are reduced by cold).

    It could be the coil(s) but without more details it is impossible to guess what is wrong.

    Do not narrow the gaps on the plugs – you will not get a big fat spark, which is what you need.

  • adam
    Lv 4
    1 month ago

    Many times its just flat out to cold. Get a block heater for it. As you stated a little warmer and it starts right up

  • 1 month ago

    "Won't start" means: cranks fine but won't start? Means you've checked for spark by pulling a plug and watching whether the plug held against the engine case sparks? You say "it's not the battery" but fail to provide the resting voltage of the battery. You don't say you've checked the ignition interlock switches on the clutch, neutral switch or sidestand. You fail to state the electrical maintenance you've performed on the bike. You fail to state if the carburetors have ever been cleaned or rebuilt. You fail to state whether the finger strainers in the tank have ever been pulled and cleaned. You fail to state whether you've installed aftermarket fuel filters. You fail to state whether the bike has a fuel cutoff solenoid, and whether you've checked it. More facts needed. Sounds like you don't know how your bike works, haven't maintained it, and don't have a shop manual for it. Fix those problems and your bike will start. Here's your current approach:

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  • 1 month ago


  • Anonymous
    1 month ago

     Replace air filter.  Check if the oil has correct viscosity.  Drain fuel and put fuel from a leading brand gas station.  Check the plug.  Check for a good spark when it is dead cold with a spark tester.  Coil or plug could be bad.   Check valve clearance.  Check compression.

    Sometimes it is just too cold for an older bike.  Keep it simple and put a block heater.

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