Carburettor Icing

Hit my first case of carb icing tonight. It's frickin cold, and after a bit of highway, it started being a dog at low rpm and running rough.
I guess that's my initiation to the Kawasaki world then?

I don't think its cold enough for carb icing in Australia
more likely to be a bloked fuel breather esp. after highway riding

It was insanely cold last night man...i'll give it a run this morning to confirm, but it only occurred after prolonged riding in the cold. Running fine one second, struggling at low RPM the next.

I've had it a few times where my GPX250 would stop after an hour or so of highway riding during cold nights. The minute i get off the bike to open the house gate, it just die in the arse.

The mechanic said it was the carbs, needing sync but after he did them he said it could be cold for the bike after running hot.

I guess its the same as you have mentioned above

Hit my first case of carb icing tonight. It's frickin cold, and after a bit of highway, it started being a dog at low rpm and running rough.
I guess that's my initiation to the Kawasaki world then?

You probably did have carby icing, it's not a myth. All zx7r P1's and P2's were supposed to have a carby warmer fitted at the first service. They used the one that comes stock on the '97 zx9r. You should be able to see it, Its on the left hand side, next to the clutch slave cylinder. Its a coolant line with a little filter, about 25mm round and 40mm long, in it.
Becaue of the HUGE volume of the 7's (and kwakas in general) air box, ther is a large differece between manifold and Plenum preasure. Air ram works by increasing the plenum preassure the quicker you go. For wide open throttle in and out corners etc.. this isn't a problem. BUT, at 100km the plenum (ram air) preasure is relativley high and with the butterflies only open a crack means massive air speed through the venturi. This does cause icing on 7's. The carby warmer does improve things, but mine does it still on cold Ballarat nights, and blueflies (without the warmer) is even worse.
Because of the 7's intended purpose, hard wide open throttle track or twisty riding this wasn't anticipated as a problem. It only even happens to me on a cold free way, get to hills and use some throttle opening and it's not a problem.
The reason they left them off origionally is that the colder the aircharge going into the engine the denser the air is and the more fuel can be carried. Denser air and more fuel equals more horse power that the engines will make. 6's and 9's aren't as bad.
To make my point, the Supergarged Bligblock Hemis we run in the boats make upward of 1500bhp and will ice up solid if they idle for to long or sit on a small throttle setting for any amount of time. We actually heat up the blower hats with a hair dryer before we start them, so that they can idle out to the start.
It want hurt anything, but is a pain in the arse sometimes.

I stand corrected

Ahh yes
It comes up every winter !!!


mario

Last edited by mfzx6r on Mon Jun 07, 2004 10:19 am, edited 1 time in total.

I used to get it on the GPX250 here in Canberra every time the mercury went below 0 degrees celsius. The ZX9R hasn't been anywhere near as bad, but on a couple of foggy -6 mornings it has done it if I haven't warmed it up properly.

i reckon it was 4 or 5 degrees when i got it on my gpx

Riding at temps of -6? You're mad (hehehe)

That is crazy!!

That is just far too cold for me!

Hey Mick, why do you ride when its so cold, is the bike your only for of transport?

I'm cold just thinking about it, I'm going for a coffee to warm up!!

I commute on the bike regardless of the temp or weather.
The coldest it's gotten to so far for me this year has been 2 degrees, then take wind chill into account.
Last year I'm sure I left home in sub 0 temps more than once, and add wind-chill to that makes it bloody cold.

You just rug up and deal with it.
ty

Hit my first case of carb icing tonight. It's frickin cold, and after a bit of highway, it started being a dog at low rpm and running rough.
I guess that's my initiation to the Kawasaki world then?

I posted a ZX7r buyers guide with Jason...who posted it under Technical stuff on the KSRC website....
talks a lot about ZX7r's and carb icing...basically nothing you can do
as the Kawasaki carb heater acts up... (the filter blocks)
have a look...

cheers

I commute on the bike regardless of the temp or weather.
The coldest it's gotten to so far for me this year has been 2 degrees, then take wind chill into account.
Last year I'm sure I left home in sub 0 temps more than once, and add wind-chill to that makes it bloody cold.

You just rug up and deal with it.
ty

Well, I suppose I too have left home when it has been 2 degrees, cause I don't live far from ty, and I ride regardless of the weather.

At this time of year I am wearing Draggin' jeans over tracksuit pants, a dri-rider nordic jacket and a polar fleece neck warmer. If it rains I add a pair of RJays tornado pants.

My fingers and toes sometimes get a bit cold, but the rest of me seems to stay warm enough !

My neck seems to be the part that suffers but by the time I get to work
its too numb to feel anything...

Ty does the fairing on the zzr cover in front of the hands at all ?
the zx/r doesn't.


mario

Riding at temps of -6? You're mad (hehehe)

That is crazy!!

That is just far too cold for me!

Hey Mick, why do you ride when its so cold, is the bike your only for of transport?

I'm cold just thinking about it, I'm going for a coffee to warm up!!

Sometimes I wonder! Basically yes it is my only form of transport, other than an unregistered, uninsured Ford XA Superbird and a VT Commodore that my wife needs to drive. Luckily it's only about a 10-15 min trip to work from were I live, but when I was going to Uni last year and the year before it was about 30-35 minutes and was usually early morning or late at night...long enough for the cold to seep in.

It's the price you pay for all the benefits of riding...