Just as a followup, I leaned the bike to the right then undid the airbox drain plug and a shitload of water came out, well at least a table spoon anyway. After draining this excess water the bike did seem to run slighlty better right away and it worked ok when warmed up however:
Temperature was -5 Celcius, clear night, no precipitation.
When giving it full throttle at low rpm in scond gear at first it drove and accelerated normally but when doing this say about 6-7 times there was a noticable drop in power. My theory is that I was puuting alot more fuel in there(and low fuel speed and throughput through pilots and mains) which had more of a chance to freeze the minute water particles up in the carbs, the freezing built up untill it affected normal operation. Also opening the throttle wide would suck in any excess condensation in the airbox which would excacerbate the icing situation. Idleing and staying still and low throttle settings till it sorted itself out helped untill it drove normally.
When driving "normally" that is no crazy burnouts and just accelerating normally the bike drove fine. What I mean by normally is just driving it like a car, shifting into another gear around 3700-4000 or so and using smaller cruising throttle inputs to keep speed up and accelerate.
My theory is it's a combo of airbox design and small pilots that are causing the problem.
Let's first take a look at the airbox.
The airbox is a very enclosed design that is more suited to a motorcycle with half the displacement of the bike than it's fitted to. To say that there is not enough airflow to either A. Evaporate the water or B. To let any condensation escape when stopped is an understatement. I'm wondering if people who have fitted and aftermarket pipe and have a modded airbox such as a Hole shot or even better Ivan's mod design are as susceptable to condensation as us stockers out there. I will be getting a jet kit in the spring so maybe in a year I'll do a followup but it only stands to reason that more holes in the airbox to help escape any condensation would seem to reduce this problem.
In addition with the stock setup you are getting a double venturi effect from the stock configuration. Having 4 carbs pull through the equivilant of just over a carb sized hole is alot of vacuum. While this produces the low speed torque and pull we all love it poses a problem. The air is going to be pre-cooled before hitting a wet with condensation airbox, then cooled further by being sucked into the carbs. Cold, wet icy air, cooled even further then sprayed with cold gasoline with minute water particles is a recipe for icing. Combine this with low throughput through jets and RPM's, and wide throttle combinations I'm suprised the carbs dont turn into one big block of ice! Again, with an airbox mod, spreading the air over a larger amount of holes would seem to help here as well.
Next let's take a look at the jet sizes. Since this problem really only seem to affect low speed operation it only stands to reason that due to the pilots being artificially small to pass EPA, and they probably don't think that us crazy people(I'm Canadian, Eh!) would be driving in the winter, would cause more problems. A 15 size pilot is a very small hole. Probably less than your average sewing needle, it would take just a little bit of icing to cause problems for this very important jet. Again with an aftermarket pipe and jetting setup there is going to be more fuel going through the jets, which has less of a chance of freezing up due to the slightly higher throughput.
Even in very cold temperatures you never really see Niagra falls freeze up solid. Why? There is enough movement and throughput to offset the freezing temperatures.
My only advice is if you have a stocker when driving in icing conditions is:
A. Before starting the bike lean the bike to the right for a few seconds then take the drain plug out and drain any excess water.
B. Let the bike idle for an extra few minutes or so at least untill you can feel warm air near the carb areas and the fuel line.
C. Try to keep the rpm's above 2000 rpm(High jet throughput). If you have to stop, dont rev the bike if possible just let it idle there at low throttle levels.
D. Dont use Wide throttle settings and low rpm, this will dump fuel into a the venturi's and may freeze up the carbs very quickly
E. If there is an aftermarket product out there that prevents fuel from freezing or a grade of gasoline such as Petro Canada's "Winter Gas". Then try to use it, I haven't done any research if this actually helps but what the hell give it a shot.
F. Don't be crazy like me and drive in Canadian winters!!! However this problem only seems to affect people at under 4 Degrees Celcius(40 F) and Wet conditions. Most "normal" people would never even dream of driving their bikes in that weather.
G. If all else fails buy a 24 of beer, park your bike in your living room and setup a large TV and a fan. Download a tank cam video, drink the beer put on your gear turn the fan on high, and turn up the T.V and pretend!!! You may be drunk enough to not notice the difference! If you have a treadmill turn that on high and drive your bike on it. Just be sure to vent the exhaust to the neighbors yard, they love that kind of stuff!
If we can nail this down, maybe it deserves a sticky in the BAndit FAQ's for us Eskimo types that drive all year. For some of us the Bandit is our primary mover. I'll do some experimenting and see if I can minimized the problem.
Topic: Carburetor Icing (Read 6895 times)