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Posted: Tue May 23, 2006 5:23 pm
by Rossi
Read this mate
Carb icing is a consequence of air being sucked into the cylinder. As it is sucked, the air pressure lowers. As the pressure lowers the temperature of said air decreases. Cold air is unable to hold as much water vapour as warm air, so at some point the temp will decrease to a point where the water vapour condenses out to form a damp film in and around the jets. (Like on a cold pint of beer) If this low pressure situation persists the temp may decrease enough, even if it's a hot day, for this condensation to freeze which is when the icing occurs.



http://www.silkoleneoil.com/techtip7.htm

Carb Icing

Posted: Tue May 23, 2006 5:35 pm
by briffa
Ok I had this happen recently for the first time.
The bike was running ok and around 4 g's it starting running on 2 or 3 cylinders.
I got extremely concerned with this as the bike previously had a problem with a pourous head, I took the bike apart and found the thermostat was stuck open so the bike wasn't getting to operating temp.
Replaced the thermo and rode in 1degree temp and bike no longer has the problem.
Just a thought
Paul

Posted: Tue May 23, 2006 5:37 pm
by photomike666
You need to rig up a pipe from just above your exhaust headers to the air intakes. This will supply you with warm dry air and negate any further problem. Also, having tubes of water tapped from your cooling system, and wrapped around the carb will help stop the ice forming.

Posted: Tue May 23, 2006 5:42 pm
by mike-s
theres a difference between doing the latter, and doing the latter and not have it leak the hell everywhere.

Posted: Tue May 23, 2006 5:50 pm
by Rossi
Not sure if the Aussie model has the carb heating circuit but if it does then the first thing to do is check the filter, the bloody things always used to block up in the UK.

1. Fuel tap to off, then philips driver to remove it.
2. chunky pliers to move the spring clip on the fuel pipe back, then prise pipe off with big flat blade driver. some fuel will come out dont worry about it.
3. Remove rear seat, undue 10mm bolt that holds front seat on, and remove front seat.
4. Undue and remove the 4x 10mmbolts that hold the tank on.
5. Remove the tank, and put somewhere safe.
6. Get a big cloth / small towel and put it under where the small white bottle is, its about the size of a cig lighter, on the righthand side below No 4 carb.
7. with the big pliers move the clips either side of the bottle, up the pipes a bit.
8. Now twist the pipes, and pull them free of the bottle.
9. The filter will be in the fatter end of the bottle, remove and kleen filter and bottle. some coolent will leak out but dont worry as its not much, water pressure and vacume stops it from pissing out all over the place.
10. Reconnect up, remove the towel, now start the bike, and when you see the first bar, or when the bike has warmed up, a little, give it a really big handfull of rev's this will pump the air out of the system. This only works before the thermostat opens. Check that carb heater pipes warm up.
11. Refit tank, fuel pipe, tap, seats, turn fuel on, start bike and go for a good thrap round, and feel smug about doing it yourself and at how easy it was.

Duane if it gives you the shits mate try any fuel additive that contains isopropyl alcohol :wink:

Posted: Wed May 24, 2006 2:10 am
by varden
My ZX9R did that, let it sit for 10 min and it was right, pissed me off tho.

Huge flat spot at 4000rpm.

Now EFI all the way!

Posted: Thu May 25, 2006 5:16 pm
by mrmina
i've got an idea, why dont u get someone to knit u a little sweater for the carbies so they wont freeze :P

Posted: Thu May 25, 2006 5:28 pm
by mike-s
mina, your a wanker.

Posted: Thu May 25, 2006 5:35 pm
by mrmina
mike-s wrote:mina, your a wanker.
i thought it was a great idea. god damn tossers with no sense of humour

Posted: Thu May 25, 2006 8:07 pm
by mike-s
i thought it was a bit funny too, but took a moment to be an arsehole and pay you out :D, no hard feelings i hope, i imagine they bounced right off yer shaved head ;-)

Posted: Sat May 27, 2006 2:49 pm
by mrmina
mike-s wrote:i thought it was a bit funny too, but took a moment to be an arsehole and pay you out :D, no hard feelings i hope, i imagine they bounced right off yer shaved head ;-)
spot on.

it was just freshly shaven too :D