I bought a 500ss Adrenaline in 04. The thing rdies great and I love the REV sleds.

However I am wondering about the heated carburetor. Can you do damage if you have it on all the time (below a certain temp, etc. ) :confused:

One thing for sure if anyone is wondering about a well priced ditch banger that will keep up on any trial, go for the 500ss.

Anyone hear of any problems with this 599 cc motor? I have 3055 miles on mine and so far so good.

Leave them off unless it gets realy cold like 10F or below.

How exactly dow heated carbs work? How do they create their heat?

Originally posted by 01MachZ@Sep 2 2004, 09:18 PM
How exactly dow heated carbs work? How do they create their heat?
343176


A coolant line is spliced after the water pump to circulate coolant through the carb body, thus keeping it toasty warm. It won't harm anything to keep the heat turn on all the time, but it apparently can rob you of some perfarmance. I didn't know this, and had mine turned on all last season... you guys better watch out this year, I predict an extra 10MPH! :D

Originally posted by 01MachZ@Sep 2 2004, 09:18 PM
How exactly dow heated carbs work? How do they create their heat?
343176


They run a very simple bypass line off the head and into special cambers on the carbs and then into a return line back into the coolant lines. The idea is to get just enough warmth into the carbs so that ice cant build up during WOT runs in realy cold weather.

Running them on all the time wont hurt anything except performance in warmer temps. Runing them at @ 15F or warmer and the heated carbs cause the fuel/air mix to run rich.

I know up here in Saskatchewan if you run the carb heaters all day when you shut the sled off for the day when its -30'Celcius the carbs end up with condensation then they freeze up overnight. So you should turn them off for the last 10 miles or so of the day. Also heard of some hard starting problems where the fuel would boil in the float bowl when shut off? Not sure if any of this is true but just my 2c.

Rev manual says turn on when 0 deg C and below (32 deg F) so I did... and got chronic fouling due to carbs running too rich. So I call up Doo and they say "OOPS, we meant 0 deg F and below."!! So now you know the REST of the STORY.

G MAN

PS - You'll know if you need it when the slides start sticking open from frozen condensation.

I have them on my 800, but I almost never use them, even when it's really cold. Only time I use them is if it's really cold and there's lots of powder and I've been drift-busting or I nose-dived a landing or something. Then you can flip them on for a few minutes to deice the carbs, but I usually turn them back off after that...

Hot Air == Less Dense == less compression

Cold Air == More Dense == more compression

Thanks Guys. So basically leave them off unless very cold or in deep powder. Will do.

As a pilot, and aircraft mechanic, I've seen Carb Heat for years. In an airplane, you turn carb heat on in high risk situations, for example, low power settings on approach. The other time you turn it on is when you notice a slow, steady decrease in RPM (you wont see this in a snowmobile with the clutch). This means that ice is slowly accumulating in the venturi part of the carb. This icing can happen at any temperature up to 70 deg F. It is most likely to occur when the dew point and the temp. are within a degree or two of each other. The downside is a definite loss of power. In fact, during preflight run-up, you turn on the carb heat and look for at least a 50 rpm drop, indicating that it is working. What does this mean for a snowmobiler? Leave the heat off unless you notice a distinct loss of performance, especially in high powder conditions. A way to troubleshoot carb icing is that when you turn the heat on, the performance will immediately get better (indicating the clearing out of all that ice in the venturi) or running really bad for a few minutes, then getting better. This means that the ice in the venturi has been dislodged, allowing it to enter the intake, until this melts off, it will run like crap, then it will get better. Until you run into obvious icing conditions, I'd leave it off. Hope I muddied things up for you:)