I have a 2002 ZR 440 Sno Pro, and it's running kind of crappy. Wondering if anyone here works on sleds at all? It's been loading up a ton at idle, and hates to get moving again. I kind of fixed that problem by setting the idle speed to 3000 rpm... Also, it isn't running like it used to as far as throttle response and top end. It takes a few seconds to hit peak rpm instead of instantly like it should.. And when you hold it wide open on the trail, it'll sometimes bog down to 8000 rpm, or even 7500 and the check engine light will flash.. Peak RPM I think should be in the 8800 range. It's stock, stock clutching, new plugs, belt i think is ok, carbs have been cleaned fairly recently, and should have decent gas in it. I figured I'd ask here before paying $85 per hour to have some grease monkey scratch his head. Thanks in advance!
my friend has one of these, he's burnt it down 3 times. changes jets on the trail and still cant get it to run right... to be honest i think you should fix and sell... if it wasnt for that info, i'd look at it.. sorry..
My guess would be carbs/jets too. You are describing exactly what my bike was doing last spring. We took the carbs apart, cleaned the jets and idled perfect. Never ran so good. If the primary jets are closed up even the slightest, the only way to idle is to have the rpms high enough that the secondary jets open up. I'd say pull the carbs and either clean or replace the jets. See if you can see light through them. We just used a strand of copper wire from some old speaker wire to clean them out. It makes a world of difference. If that's not it, it seems like the the next culprit would be fuel delivery. (lines and what not).
I may be able to take a look at it. Is the thing completely stock? When you say the carbs were cleaned were they fully taken apart? Did the carbs get synced after the carb job? It sounds like the carbs are gummed up. It doesn't take more then one summer to kill them.
I'd say replace all jets (if carbed)... go from there... our polaris 340 we rebuilt with a brand new engine etc, wouldn't run, a customer who was a snowmobile techfor polaris said replace all jets etc.. did.. ran first pull
Thanks guys! I'm guessing it's the carbs too.. They were cleaned a year ago, but I know it doesn't take much. I've had it for three years and never touched the jets either.. It's always ran great so I haven't done much with it, and it's gotten pretty dirty too. My cousin works at a shop that is new and trying to get business.. He told me to drop it off and for under $100 they'll clean and snyc the carbs, replace the jets, new fuel filter, change the chaincase oil, put a new set of plugs in, grease everything that may need greasing, give everything else a once over, and make the engine bay look brand new. Sounds like a fair deal to me. I dropped it off last night and they are doing all that today, I'll let you guys know how ti runs wheni get it back!
cleaning a snowmobile carb consists of more then spraying it with carb cleaner, you gonna get in there, my guess is the pilot jet is plugged. also arctic cat FTL
yup, pull the pilot and main jets, soak 'em for a while in cleaner and then blow them out with compressed air
I got my carbs sonic cleaned by this motorcycle restoration guy and I think I gained like 50hp.... Well it feels like 50 hp. Plus syncing my carbs made a big difference.
Update... I just got off the phone with the shop. They did everything they said they would(cleaned/synced carbs, replaced jets, etc) and also found that one of the power valves was completely stuck/gummed up-fixed that.. They fixed and shined it all up and it apparently ran stronger than they've ever felt a 440 for about the first 10 minutes or so. Then the same problem returned.. At w.o.t. the check engine light flashes, and when it is flashing the motor cuts back to about 8500 at first, and basically gets worse until it settles around the mid 7000's (about 55-60 mph).. Now they are scratching their heads and so am I. It's almost like it's putting itself into some type of limp mode. When you slow back down and punch it again it'll hit peak rpm then back away. Also, if it's on a plowed road/ice it seems to not do this, as much at least.. Any other ideas?
Wait a minute....is this one of those batteryless EFI setups? if it was still carbed it wouldnt have a check engine light...
It's carbed... They don't make efi snowcross machines. The light is yellow and says "check engine." Apparently there is some type of light that flashes and some type of diagnostic port on the cdi box to see what code it's pulling. Just found that out from Arctic Cat. I didn't know sleds were this complicated...
Problem solved! The temp sensor was bad. Same thing as an 02 sensor in our cars, sensor went bad and threw a cel. Except my snowmobile was basically running itself in kind of a limp mode because the exhaust is variable and without being able to read the temperature it didn't know how to run. So it basically was keeping itself from blowing up. $50 part, easy fix. Thanks for the help everyone!
