I think you may have misunderstood what carb icing actually is. It's not the petrol itself freezing, but the moisture sucked in with the air that freezes due to the pressure drop as it's sucked into the carb. This causes ice crystals to form which then block up the jet(s) and cause fuel starvation. A less volatile mixture may indeed reduce the freezing point of liquid petrol, but shouldn't make any difference to this phenomenon. -- _______ ..'_/_|_\_'. Ace (brucedotrogers a.t rochedotcom) \`\ | /`/ GSX-R1000K3 (slightly broken, currently missing) `\\ | //' BOTAFOT#3, SbS#2, UKRMMA#13, DFV#8, SKA#2, IBB#10 `\|/` `
IIRC, despite the name, carb "icing" doesn't actually involve ice at all. Isn't it caused when the temperature in the air stream drops below the dew point, causing water vapour in the air to condense in the jets? But yes, this is still true. However, ISTR that one way of lessening the effects is to use a mixture which includes something in which water is soluble, although I can't remember what that is. The so-called winter-grade petrol may include some of this.
Eddie says... Dump the antiquated piece of carburretor laden crap and move into the 21st century. Buy a bike with fuel injection. -- Lozzo Triumph Daytona 955i SE (Black with added black bits) GSF600SW (broked) 'I do not object to people looking at their watches when I am speaking. But I strongly object when they start shaking them to make certain they are still going.' William Norman Birkett, 1st Baron Birkett, Oct 1960.
Hog says... The Gixer didn't and I haven't ridden the Gaytona in cold enough conditions to tell. It does seem to be mainly a Kawasaki thing, but it has only ever happened to me once, and that was on my 2nd ZZR1100 on the M1 one morning. -- Lozzo Triumph Daytona 955i SE (Black with added black bits) GSF600SW (broked) 'I do not object to people looking at their watches when I am speaking. But I strongly object when they start shaking them to make certain they are still going.' William Norman Birkett, 1st Baron Birkett, Oct 1960.
My Monster did as well. No idea which cylinder, but it would happily die. Fixed with 'posh' petrol. -- Catman MIB#14 SKoGA#6 TEAR#4 BOTAFOF#38 Apostle#21 COSOC#3 Tyger, Tyger Burning Bright (Remove rust to reply) Alfa 116 Giulietta 3.0l (Really) Sprint 1.7 75 TS 156 TS S2 Triumph Speed Triple: Black with extra black bits www.cuore-sportivo.co.uk
My GPX750 did it as soon as autumn arrived. Used to hit the icing point just as I reached the big roundabout near us (Cooper Dene at Bournemouth) and the engine would be fine until I slowed to approach the roudnabout. As soon as I opened the throttle to carry on the engine would die. Every time. I did catch on after the first couple, but that combined with the traditional Kwak off/6000rpm choke made the darker morings more 'interesting'.
itycb right. My GPz750R did it from new, which made running it in a right git, and it stalled *every* morning at the end of the Westway, from October to March. The bloke at Pineways informed me that "they all do that, mate", as if that was okay, on a bike I'd just HP'd my life on for the next three years. -- | ___ Salad Dodger |/ \ _/_____\_ GL1500SEV/CBR1100XXX/CBX1000Z |_\_____/_| ..87753../..22653.../..31893. (>|_|_|<) TPPFATUICG#7 DIAABTCOD#9 WG* |__|_|__| BOTAFOT #70 BOTAFOF #09 PM#5 \ |^| / IbW#0 & KotIbW# BotTOS#6 GP#4 \|^|/ ANORAK#17 IbB#4 YTC#4 two#11 '^' RBR Clues: 84 Pts:1800 Miles:5704
My fuel injected Zed never has, but the VN (carbs) did it for fun. In fact, the VN did it so much I suspected a faulty pair of carbs, so I changed them in an "elimination exercise". Different carbs, same problem but the Zed has never shown even a hint of the problem. -- Beav VN 750 Zed 1000 OMF# 19
Something like that. Worked very well with Elly's 9R, which iced like a bastard commuting up the M1. Having said that, it was tolerable on the motorway, just a bit of a snag a) getting down from 175 WFO in time to make the off-slip - and b) getting away at the top, then round the roundabout in heavy traffic. Filtering was a little on the dodgy side too, iirc. It can be difficult to source - Wynn's Dry-Fuel, intended to absorb moisture from fuel tanks of laid-up vehicles also worked well and may be easier to lay your hands on, there being more Wynn's stockists than Silkolenies these days.
I thought the problem was caused in part by the latent heat of vaporisation of the fuel; that is, it takes heat from its surroundings in order to evaporate. These surroundings are, of course, the carburettor. It is quite possible in the right conditions for the temperature of the carburettor not only to fall below the dew-point and therefore suffer from condensation, but also to fall below the freezing point of the condensate, i.e. icing. I suspect it depends on the LHV of the fuel, which could be changed by changing the components.
On Monday 23 October 2006 09:35, Eddie [] wrote in message My FZS600 had a very bad bout of "carb icing" last spring. Turns out the plug gaps were way too wide[1] and the carbs were out of balance by quite a lot. The plug gap was the main culprit though. [1] When measured, they turned out to be more than double what they should have been. They looked ok to me but then I'm used to old Land Rovers.
Pro-FST: British Technology Engineered in Britain. Pro-FST (Fuel System Treatment) was developed in 1992 following an unofficial request from Kawasaki Motors (UK) Ltd., for something that would deal with the particularly British problem of carburettor icing in damp, cold weather. (It was also specifically a motorcycle malady. Cars have room for heated air intakes.) KMUK were harder hit at that time than the other 3 big Japanese MIC manufacturers, because they sold a lot of 'GT' models to dispatch riders, who obviously covered a lot of miles in all weathers; there were also a lot of complaints from the 'off road' fraternity. John Rowland, (R & D Chemist) (Your writer has run into this one! The throttle slide in the AMAL carburettor of my 990cc Matchless engine, on a Morgan 3-wheeler, would sometimes freeze up so badly that I had to drive on the ignition cut-out like a Sopwith Camel pilot! I am now a Pro-FST user.)
