Post by anon on Jan 31, 2007 21:02:21 GMT
From: Muddy Rutter Sent: 08/01/2003
Looking at the snow out of my window, it seems good time to post this message.
There have been previous threads about carb heaters and relays and other members may wish to add their wisdom to this thread.
For the moment this text below from a VFR site seems to pretty well sum the situation up, although the engine mis-running characteristics don't seem to be the same as for the Divvy.
One option is Lead Replacement Petrol or the Silkolene additive mentioned in the text below. Another Kawasaki site noted that it is essential to keep the fuel filter to the carbs clean/new.
Regards,
Nick
This is from homepages.ed.ac.uk/trs/VFR.html and refers to a VFR
In cold and damp weather it suffers from carburetor icing. If you have not experienced this, the symptoms are unmistakable. The bike starts up fine, but after a while it will not run at very low revs. The problem then starts to affect the engine at higher revs, and will climb up the rev range until you cannot ride properly. It is worst if you ride fast, and then suddenly slow down (pulling off a motorway for example). If you stop, the engine will not idle; but if you rev it, it just gets worse until it dies. After being stopped for a few minutes, the engine will run perfectly normally.
(Riders outside the UK may not experience this, since the petrol sold in different countries varies in volatility: UK petrol tends to have quite a high volatility which makes this problem worse.)
All that is happening is that the fuel evaporating in the carbs makes them cold, and in a damp atmosphere ice forms inside the carbs. Because of the chilling effect of the fuel evaporation within the carbs, this can happen at ``outside'' temperatures of up to 5 Celcius. This initially blocks the smallest jets in the carbs and affects the engine at low revs. The more mixture that passes through the carbs, the worse it gets, so riding fast (or revving the engine at a standstill) makes it worse.
The simple solution is to stop and kill the engine (which stops any more ice forming) as soon as you notice a problem, and wait for the engine heat to thaw the ice. Obviously this is inconvenient! Some people recommend using 4 star (the UK name for high octane, leaded fuel) petrol. The best solution is to buy some Silkolene Pro-FST (fuel additive) which you just pour into the petrol tank. This cures the problem totally, and £ 3.50 for 500ml used in 0.5% concentration (they recommend 1-2%) it adds no more than about 10% to fuel costs, which is cheaper than 4 star
From: rowlf Sent: 24/02/2003
I can vouch for Silkolene Pro-FST in my 900 Diversion. I was having problems with carb icing and cured it by adding Silkolene Pro-FST, although I am using 1%. mixture at the moment I might try .05%.
Carb icing can cause increased fuel consumption as the gradual loss of power is compensated for by using extra throttle, often without noticing. The combination of this and the richer fuel mixture caused by restricted airflow can waste petrol, so the cost of Silkolene Pro-FST may be worth it.
It cost me £8.99 per litre though.