Cold running problems - but starts OK

[Caakman400]

Bike starts like a good 'un in the mornings (was -1C last week) and rarely needs choke. Problem comes 10-15 minutes later...I'm flying down the road keepin it less than 10,000 cos the road is like ice, start gearing down and braking for the red light, bike won't want to hit the low revs and feels like it's going to stall at any second. If I keep it above 4,000rpm in 1st it's OK, though the exhaust sounds like a tractor c oughing. It's difficult to get any revs to pull away too. It just won't idle below that figure and almost cuts out at 5,000 too. I thought carb-icing would effect the whole rev range? Any ideas? (I'm in Japan by the way, so if you want to recommend Halford's Dry Fuel you could always send me a bottle )

[rover220]

deffo sounds like carb icing, has it only started doing it in this colder weather?

[masterofinsanity]

i was gonna suggest carb icing, i suppose with the higher revs the engine is going to be warmer so less chance of the carbs freezing, but then again the higher revs the faster you're going then the colder air foced into the carbs, tricky one, do you have carb heaters fitted??

[Caakman400]

Cheers for the replies.

Yup - problem only started on very cold mornings before the sun is fully up. I have a one hour ride to a job out in the sticks and the further out of the city - the worse the problem. My journey starts at 7am so pretty blxxdy cold!

Don't know about the carb heaters - read they're on a lot of Japanese models so will check when I have the time. Once the sun breaks and the temperature gets above 4 - 5C the problem goes away, so definitely cold related. I have a Nassert-R system (http://www.beet.co.jp/kawasaki/zxr400r/index.html) - wonder if the exhaust could be the problem? Can't really think of anything else.

[zxr_oli]

I get pretty bad carb icing, wanted to stall if i go below 3/4 throttle.
So it's either go fast, or not atall

I did use Wynne's Dry Fuel, which seemed to help for a few tanks, but now it's begun to get bad again.

[Caakman400]

Sounds like the same thing. At least you're able to go fast mate...I have possessed-by-the-devil rush hour traffic, drivers with no lane discipline, and a continuous string of irritating red lights. I feel like a right nob waiting for green with my idle pinned on like 6-8,000rpm and the muffler farting like a sick tractor...

Does warming up the engine for longer help?

Anyway, think I might take my scooter tomorrow...and I eff'in HATE scooters...miiiiihhhhhhhhhhhhhhhhhh

[RedexRobB]

If youve got the carb heaters then running the engine for longer on warmup might help.

[Northern ANdy]

better make yourself some way of heating the air/ carbs

[Caakman400]

Sounds like carb heaters are the way to go. I'll speak to my garage about them - haven't got a clue where to pick some up in Japan

My morning run wasn't so bad today. I found that keeping the bike on idle at the red lights helped melt the ice blockage even if it stalled a few times - before I'd been keeping the revs 3/4 throttle to keep it from stalling. I guess the light flow of petrol helped the ice to melt. It's a blxxdy black science any roads...

To all you winter warriors out there- keep it safe

[zxr_oli]

I plan on tearing apart a 12V hair dryer, and shoving the heating element inside the airbox
Hopefully it will prevent carb icing

[Caakman400]

...the resulting fire in the air box should keep your hands nice 'n toasty !

For any other riders in Japan in the forums, Dry Fuel is called "mizu nuki zai" in Japanese. You can shell out a ton for it at the gas stands, or pick it up cheaper at Daiki or Konan. The kanji is: 水抜き剤