Carb icing season starts...

Originally Posted by on yer bike

carbs... what are they?... hehe

I'm on the Atkins diet as well* :P





*Not really

[northwind]

Originally Posted by scooby2102

Dont really think additives are good value, especially in this country since to get petrol to freeze we would need ambient temps of approx -70C

Carb icing isn't caused by low air temperature, but it's made possible by moist cold air... It's caused by the pressure changes in the carb. The venturi raises the air speed without raising the volume, which lowers its pressure and, as per Boyle's Law, the temperature. You don't tend to get carb icing at significant minuses, since there's not enough moisture in the air to do it.

Oh yes, it's also not caused by the petrol freezing.

Originally Posted by northwind

Carb icing isn't caused by low air temperature, but it's made possible by moist cold air... It's caused by the pressure changes in the carb. The venturi raises the air speed without raising the volume, which lowers its pressure and, as per Boyle's Law, the temperature. You don't tend to get carb icing at significant minuses, since there's not enough moisture in the air to do it.

Oh yes, it's also not caused by the petrol freezing.

I noticed when its foggy at about 3-5 C is when its worse... below that the problem goes away.

Its not the petrol that freezes, its the drop in air pressure that allows the moisture in the petrol to condense on the carb venturi which in turn freezes

Pete

[northwind]

Welcome to 2 weeks ago

It's moisture in the air more than moisture in the petrol- though that's just being picky, did you mean the air/fuel mix?

Originally Posted by northwind

Welcome to 2 weeks ago

It's moisture in the air more than moisture in the petrol- though that's just being picky, did you mean the air/fuel mix?

yep, thats why I notice it more when it gets foggy...

...just had a nightmare ride home with what I think was the carbs icing (cutting out at low revs) in some lovely freezing fog. What more could you ask for, can't see anything, bike stalls, rear wheel locks as the roads bloody icy. Bring the summer back! Or just not freezing fog or ice...

I think I'll be filling up on optimax (or whatever it's called) next time and seeing how that runs. Where can I pick up some of those additives? Is carb icing common on the SV?

cheers

Jamie

[northwind]

Sounds like carb icing to me. The additive is a Silkolene thing, you can generally get it from bike dealers that carry the silkolene range. Suzuki and Kawasaki dealers will be better, I reckon, since those 2 have a real history of carb icing.

It's not so much an SV thing, more a carb thing. Some bikes get it worse than others though. SVs get it fairly bad.