[ShaunC]

I think I have carb icing but am not sure,

the symptons are after about an hour of riding in low temperatures my bike starts to struggle with carburation, I pull the throttle back and it splutters for a sec and then picks up again.

If I stop the bike for a couple of minutes it is fine again for a fair while.

temperature of the bike whilest it is running is fine.
Any thoughts?

Thank in avance
Shaun

 

[casadepunklife]

Hmmm. I suppose it could be. Does it do it regardless of humidity? If it does ok in drier cold weather then I'd bet that's it. I'd think that keeping the rev's down a bit when you think it's likely to happen might help avoid it. Not much you can really do about it. carb'ed planes have carb heaters to deal with this. This is pretty surprising to me on a bike though. You never hear about it with cars, maybe the hood helps hold heat in. Maybe try some kind of inslauting.

 

[Freakinout]

you could also be running lean, does the bike run hot if the weather is warm and you've been running for awhile?

 

[twowheelertoy]

You didn't say what bike your running..

The weather over here isn't that cold so i am doubtfull it is icing.

 

[Uncle Bob]

Turn down the A/C.

 

[Aikata]

Turn down the A/C.

:lol: LOL!

 

[ShaunC]

It's a ZX7R P2 1997

 

[casadepunklife]

You didn't say what bike your running..

The weather over here isn't that cold so i am doubtfull it is icing.

I don't think it needs to be particularly cold, it has more to do with the humidity/temp. Dewpoint is the term I think. The cooling is done by the carb venturi. As air passes through a venturi it creates a pressure drop. Reduce the pressure of any body of gas (or liquid or solid I suppose) and the temperature also drops. If there's enough moisture present and the surface of the carb isn't kept warm enough from the engine's heat, it'll ice up. Alright, now everybody knows I'm a nerd. :roll:

 

[ShaunC]

OK, to be fair It has always been damp when this has occured, so that makes sense.. (I think) :?

 

[Tart]

Carb icing

kwaks are renowned for carb icing in the uk, silkolene do a additive called fst which will stop it happening again. definately recommend it, i had a zxr kick out on me a few winters ago as the power came back on fully going round a corner suffering iced carbs. not a good thing to happen.

 

[rubyrubyruby]

Hi there ShaunC,

I have a ZZR1100D4 and it only seems to be in the cold/damp/foggy days that i to am experiancing this (icing) up of the carbs.
It happened to me on Monday during the fog that we had. Not a very good experiance, running on only 1 or 2 cylinder until it defrosts itself...

I have been told that Kawasaki know about this little problem, i do believe that you can get little carb heaters fitted by Kawasaki dealer, i must look into this myself.

Cheers

 

[Bren]

I had carb icing with my ZXR750H2 when it was cold and foggy or the temperature dropped close to freezing. Kawasaki did a recall over here to modify some air pilot jets and the fuel tank breather arrangement to cure it but it didn't stop mine.
Sometimes it would go away if I stopped and held a high tickover to let things warm through, other times I would have to disconnect and empty the fuel filter and pump which would have about 30% water in with the fuel.
Constant topping up of the petrol tank to keep it brimming and adding a fuel additive helped but I would still have to empty the whole petrol tank once or twice a winter to get the water out.
In the end I bought some longer piping and stainless bracket strips and moved the pump and filter up closer behind the engine every winter.
I've never had the problem on my L3/9R but it has a different petrol tank cap & filler to the H2 with an extra rubber seal inside the locking cap as well as a larger seal that it shuts down tight onto.

 

[rubyrubyruby]

Hi there Bren,

Thanks for that info but i have been in touch with Kawasaki dealers up here and they did say that these bike had been recalled years ago for a modification to the carbs which they added the hot coolant pipes throught the carbs to help keep the fuel from freezing.
What i did, stripped down the coolant system, because i thought maybe an air lock in the system, and put in some Pro FST in the tank, which prevents carb icing.
Took the old girl out in the cold, (-4) that day, and she ran without a hitch.

I have heard that if you do experiance carb icing, the best thing to do is (as you say) sit with the revs up which inturn will heat up the fuel within the carbs, then after a couple o minutes you can be on your way...

Kawasaki carbs are about the only ones that i have heard of this, seems strange in this day and age with technology that you do still experiance carb icing.

Never mind soon be the good weather...:-D :-D yeeeehaaa

 

[Bren]

Not sure about the ZZR youre riding Ruby, only kwackers I've had have been ZX/R series and two-stroke triples, oh and a crank munching scorpion one winter as a teenager.

With my early ZX series bikes the problem was due to condensation and/or water entering into the fuel system. The fuel tank breather arrangement just vented straight through from the bottom to the sides of the petrol cap into a lip where moisture could collect and just run into the tank down the tiny breather holes. On my later machine it vents right up through to the top of the petrol cap and there are extra seals that seem to provide a much better one way arrangement.

On my H series ZXRs the stock location of the petrol pump, filter and pipes made a sort of J shape and the moisture froze in the lowest pipe restricting the fuel flow to a trickle above it or in worst weather conditions complete fuel starvation. That's why I just moved them to dramatically reduce how often the problem occured-it was too much hassle trying to adapt a later fuel tank.

Not sure about having heated pipes near the carbs in summer though, would be ironic if it sorted your ZZRs freezing but led to fuel evaporation in hot weather.

Still it's nice to see there are still every-day bikers out there, through the winter I don't see a hundredth of the other riders that are about around here the minute the barometer says it's safe on summer weekends.

 

[Bren]

Forgot to say hi to twowheelertoy, you must be quite close to me as I live on the Beds/Northants border near Santa Pod. And as I've been riding through freezing fog and even the odd bit of light snow lately can I have some of that not very cold weather you've got a supply of please lol.

 

[JimmyD]

I doubt you'll get a reply, twowheeler's last post was in 2004.

 

[GREENISBEST]

Forgot to say hi to twowheelertoy, you must be quite close to me as I live on the Beds/Northants border near Santa Pod. And as I've been riding through freezing fog and even the odd bit of light snow lately can I have some of that not very cold weather you've got a supply of please lol.

Ummm that puts you around Poddington/Wymington/Bozeat, Nasty area full of reprobates me thinks :wink:


ZZR1100 D4 should have the carb heaters fitted, You may need to check that the Coolant filter underneath the carbs is'nt blocked as that will stop the flow of warm water to the carbs to stop the icing..

Because there a right tart to get at having to pull the carbs they get forgotten and soon bung up........!

 

[Bren]

Yep, am in Rushden, land of the living dead. Moved out here over 10 yeras ago and haven't managed to escape yet but at least I haven't turned local! Still at least it provides easy access to the old A45 to St. Neots one of the country's great biking roads.