Carb Icing

[Graham66]

I think I am suffering from carb icing on my little 125, basic symptoms are starts ok, runs ok for a mile or so, slowly gets worse and worse until keeps stalling - if I wait 5 mins (i.e. fill up and wait to pay) then it will start again OK and run fine all the way to work. When it is running rough I can smell unburnt fuel which makes me think it is over fuelling (not enough air getting in?) Had the bike looked at by a mechanic and they couldn't find anything wrong apart from a sticking exhaust valve which they sorted

On days that are not too cold bike starts and runs fine and on the way home from work all is fine - bike is kept in an underground car park during the day and out on the street at night

So, what can I do to avoid the problem? Would a bike cover help at all? Can I get some sort of carb heater fitted or redirect some of the exhaust heat somehow? Should I be starting the bike and letting it warm up for 5 minutes before riding off? (Currently I start it, put on helmet and gloves then ride off)

Bike is a Yamaha 125 Virago of that helps!

Graham
PS - I am new to bikes, hence the 125 and basic questions!

[rumpelstiltskin]

Try obvious things to keep it warm:-) like a good bike cover,put a blanket over engine,buy a small portable heater(small caravan heater or something),run that for half an hour or so where you keep the bike before you leave if thats practical.I remember i got a small electric blanket type thing that run off the automatic choke connection on my VW Beetle to help carb icing:-)

[ph'er(zzr1200)]

Hi,

I get the same problem on my bike, but if I let it run until it is warmed through before riding it is usually ok on all bu the coldest days, there is an additive you can buy to stop/reduce carb icing that you add to the fuel, most bike shops should keep it on the shelf. If the bike is water cooled try blocking off half the radiator as this ensures that the engine warms up enough for the thermostat to open whilst on the move, the carbs usually have a water circuit that runs through to help prevent icing and improve atomisation so keeping the coolant warmer helps this.

Hope this helps,

Paul

[Graham66]

Thanks for the replies

Bike is air cooled so no chance of blocking off the rad

I guess it is buy a decent cover and warm it up for longer before riding off

Cheers
Graham

[tcowjww]

My 1996 Honda CG125 had a small electric carburettor heater to prevent icing (the CG is also air cooled, so no opportunity to take a feed from the cooling system either). Did Yamaha equip the Virago with a similar heater?

May be worth having a look in the Haynes manual if you have one, and seeing if you have an electric heater which is not operating correctly. Is this the first winter you have experienced these problems?

[sierranut]

could be a wild shot in the dark but it sounds electrical to me. Had a simalar problem with a coil on my car. It overheated and as it was breaking down stopped working. let it cool and it started working again. Fairly certain the cg has some kind of coil to make the spark. It would explain why you smell fuel when it plays up.