cold curvy
 

my curvy is a bitch to start when it is very cold, it will fire for about 2 seconds then it doesnt want to know after that. the battery goes flat quickly aswell, is this normal or do i need a new battery? thanks

My curvy dosnt like cold starts either. Give it full choke, and when you hit the starter button give it some throttle too. Try blipping the throttle to encourage it to warm up aswell.

Could be a case of carb-icing though? I don't know..

Matt

An engine-builder and biker mate of mine (used to build up the Audi Group B Quattro engines back in the 80s) would slap you round the face with a conrod for suggesting that.

A short cut to a short life he'd say. Always recommended to start engine on choke, let revs settle, and ride/drive away gently straight away, gradually reducing choke as engine warms, avoiding high revs and high cylinder pressures (produced when maximum torque is generated) until thoroughly warm.

Don't know if it's true, but I trust him, and so did Hannu Mikola and Stig Blomqvist.

Taint carb icing, too quick... Mine'll do that if I don't have enough choke on, could it be that? When it turns over, does it sound healthy or tired?

And if it does have enough choke, and assuming that the choke is cable operated, is the cable adjusted correctly so you're getting all the travel you should?

Mmm. I also hold this opinion, but if you gotta get your bike warm and its not idling at all, even on choke, this seems to be ok for a minute. I'm carefull to avoid stressing the engine when its cold, but you can't alway avoid it (unless you have a heated garage!)

Matt

Iridium spark plugs have made a differance to my cold starting, full choke, no throttle starts no problem:? mind you i do like in a sub tropical part of the country :lol:

As your battery goes flat quickly there's a good possibilty that your battery is goosed or that you have a charging fault. Either will give you low battery voltage which will affect the ignition quality and thus cause poor starting, and the worse the starting conditions the worse it will be affected.
Check the charging system and battery first, there's a fair chance that's where your starting troubles lie.

Absolutely 100% correctamundo! :lol:

Blipping the throttle is the best way to get plug fouling; that was the essence of a plug-foul test we developed to check for likely problems we might encounter with repeated start/stop during production/delivery at a certain midlands luxury car maker. :wink:

When cold a carb engine should need choke, or put it this way it will need extra air just to be able to produce some more torque required to run it when cold, and it needs extra fuel because less evaporates in the intake port to provide combustible mixture than when it's hot (fuel wets the walls and condenses in the chamber so isn't available for burning during the first few cycles).

If your carb engine will start at, say, zero-C without choke then it's almost certainly running too rich anyway.

Best way to warm it up is ride it gently for a few minutes if at all possible. If you can't do this for some reason, just hold the throttle slightly open and put the choke off as soon as it'll run happily, and hold the throttle steady.

...and yes, iridium plugs do definitely assist cold starting (partly due to increasing the lean limit for ignitability of the mixture, offsetting some of the above wetting issues etc, also they have a reduced voltage requirement for the spark so give the rest of the ignition system an easier life).

...and Sid's comments on batteries are spot on too. A lot of starting or stalling-after-start problems on cars (typically older generation injected ones at that) are solved by fitting a new battery, it's often to do with voltage compensation during afterstart when the battery is trying to recover from being hit with a cold start. Fuelling is adjusted to allow for the reduced voltage working the injectors which slows the opening and reduces fuel flow for a given pulse-width, but it doesn't always cope with a poor battery condition and slow voltage recovery etc.

Re: cold curvy
 

I had the exact same problem this winter. I found that it would only start up off the choke, but then die straight away. I could sometimes manage to put the choke on quickly which was also a bit hit and miss. In the end, it turned out that the choke cable had been sticking (a common problem on SVs) and the plugs had become fouled up as a result. Do you experience any roughness of the engine while riding? My battery went flat quick aswell. Those engines take a lot of power to turn over.