Carb Heaters

Right. So my Curvy has carb heaters.

Question is- do they come on as soon as the ignition is turned to on (before starting the bike)?

Second question is- is it a good idea in these sub-zero temperatures to therefore switch the bike on and leave it for a 30 seconds or so before starting it (with lights off, so as not to drain the battery). Will it make any difference?

Cos the bike is a bugger to start on these uber-frosty mornings...

[TSM]

consider that they dont exist

check battery charge, a weak one will make it very difficult to start in the morning, after bike starts, dont twist the throttle as it ususaly makes the bike choke until its been running for about 10-20seconds

[Biker Biggles]

Carb heaters are not there to help start it,they are to prevent carb icing when you are going along.They are fairly useless either way.
As for starting,I would not switch on and wait 30 seconds.What you need is maximum battery wellie going to the starter and ignition.

Ah. I see. That all makes sense. Was just a thought anyway.

Yeah- heading down the A3 at 80 at -4c.* The bike doth struggle at the end of that...

Cheers folks.

* Hey- there's a thought. I wonder what the windchill would be on that...

[squirrel_hunter]

Originally Posted by thedonal

So my Curvy has carb heaters.

No it doesn't

I don't think either of my SV's have them. In the winter I switch to the premium petrol to help prevent carb icing, but even in this weather it starts to protest.

As to starting, yep in this weather I get problems. I find it better to get the engine turning over without the choke and then shoving it on as it catches. I also keep a spare fully charged battery for those testing times.

Originally Posted by squirrel_hunter

No it doesn't

. I find it better to get the engine turning over without the choke and then shoving it on as it catches. I also keep a spare fully charged battery for those testing times.

Yeah. I"m ending up doing the same- the bike doesn't generally want to start with choke on- I thought that having the carbs cleaned and set up and replacing the choke cable would have sorted that. But no! Not in this current arctic nastiness!

[embee]

UK spec curveys had the heaters fitted, imports generally didn't (not that it makes much difference by all accounts).

I've always found full choke but not touching the throttle gives a quick reliable start from cold. If you crack the throttle it seems to mess up the choke enrichment balance and makes it reluctant to start. Having said that I have to confess my bikes are SORN at the moment, can't be doing with winter riding these days.

Originally Posted by embee

UK spec curveys had the heaters fitted, imports generally didn't (not that it makes much difference by all accounts).

+1 on this.

I was having a lot of trouble with carb icing a while ago and I think it was YC who suggested moving the sensor for the carb heater away from where it is as standard which is right by the engine so it always stays nice and warm and never switches on the carb heater.

*Off to find that thread.*

[Viney]

Hmm, i am here to say that the carb heaters do work...of sorts. During my recent service i realised that they where not connected (Oversight on my behalf last time i took the carbs off i suppose) anyhoo, my SV was running badly and was becoming increasingly difficult to start. However, after plugging them back in, the bike was fine, and runs far better now. So, although that might not do a lot, i am more than positive they do something, still not a five bar electric fire thats needed sometimes to stop the carb icing though!!

Sorry my mistake twas embee.

Originally Posted by embee

The carb heaters were a very marginal benefit, if any, and certainly don't prevent icing.

Originally Posted by embee

One issue with them was that the heater sensor, a flat black disc item tucked into the wiring under the tank on the right hand side IIRC, sits in a reasionably warm place so as often as not it doesn't switch on when needed. Find it and get it out into free air if possible, easier with a faired version.