Suzuki Club UK

out of the two engines I have run, 970cc and 1590cc vit lumps, both with standard carbs. I have found that if you run anything other than standard air box with the option of the hot air feed you will suffer from carb icing, i was running just a k&n cone filter on my vit for a bit and it suffered from serious carb icing issues on motorway runs even when it was wasnt that cold and even more when it was raining. I put it back to the standard air box and even without the hot air feed it improved! on the 410 i had a rubber sleeve to block up the hot air feed when wading and offroading as it's not as bad at slow speeds, just when you are out on the road.

carnut wrote:strange??? it dosnt seem cold enough to ice up,, (must be colder were you live), i had a thought, your snorkle, does it face into wind, ie forwards. that would give the efect of ram air. if i were you, disconect it at the carb, then see how she runs!.
andy.

It doesn't have to be particularly cold for carbs to ice up - about 5-7 degs C with 60%+ humidity will be ideal for this if the carb is prone to the condition. When I used to ground run aircraft with gas turbines fitted it was mandatory (in peace time) to refer to a graph if certain atmospheric conditions were present to ascertain whether the engines could be run. If you ever want to see icing up - watch an old aircraft air intake (most are heated today) in the described conditions - about 100lb accumulation of ice in 5 seconds.

cheers guys, i will have a play about with the various options and let you know what happens.