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Closed loop - poor fuel mileage

Joined
Mar 5, 2019
Messages
245
Age
46
Location
Ottawa ontario
Country
Canada
Snowmobile
Yamaha powered CAT
Anybody have poor fuel mileage going to closed loop?
Mine is noticeably worse than before and even compared to other sleds with similar setup and riders (but not closed loop). Over a 5 litres difference on fill-ups.
Sled runs well, lots of power. I DONT have an AFR gauge to confirm ratio. Temps are cooler here for sure, was just surprised that fuel mileage is that much worse than a comparable tune without closed loop.
I have no codes in the dash so assume the O2 is working well.
Anything else I could look for? Or is this the way it is?
 

Hmmm...In cold temps it should at least be equal if not a little better. I have found the biggest difference is when it's warm.
 
Anybody have poor fuel mileage going to closed loop?
Mine is noticeably worse than before and even compared to other sleds with similar setup and riders (but not closed loop). Over a 5 litres difference on fill-ups.
Sled runs well, lots of power. I DONT have an AFR gauge to confirm ratio. Temps are cooler here for sure, was just surprised that fuel mileage is that much worse than a comparable tune without closed loop.
I have no codes in the dash so assume the O2 is working well.
Anything else I could look for? Or is this the way it is?
I don't find it to be a big difference but I'm definetly not burning more fuel than I was before installing CL. Who's tunes you running?
 
My mileage is relatively good with tune and closed loop and actually better then the other SWs in my group. Its definitely not worse then before closed loop.
 
Anybody have poor fuel mileage going to closed loop?
Mine is noticeably worse than before and even compared to other sleds with similar setup and riders (but not closed loop). Over a 5 litres difference on fill-ups.
Sled runs well, lots of power. I DONT have an AFR gauge to confirm ratio. Temps are cooler here for sure, was just surprised that fuel mileage is that much worse than a comparable tune without closed loop.
I have no codes in the dash so assume the O2 is working well.
Anything else I could look for? Or is this the way it is?
I have dash flash so can read AFR. But without dash flash if I remember correct you can read afr on hour meter I think.
 
I have dash flash so can read AFR. But without dash flash if I remember correct you can read afr on hour meter I think.
Ok will have to check hour meter since I don’t have dash flash. Although I thought hour meter displayed boost?
 
What mods do you have to your sled?
TD max spool 17, BOV, 3 bar, CAI, 2.5” mod stock muffler.
1.5” track with 96 studs. Prior to this was running MS16 with stock muffler.
As mentioned , I ride with a buddy with exact same engine mods and track, but he has maxspool 17 without closed loop. He gets noticeably better fuel mileage
 
Ok will have to check hour meter since I don’t have dash flash. Although I thought hour meter displayed boost?
It does show boost but I think a way to switch between the 2? But now that I think about this some more you may need to have flasher and Gap phone app to change. So you may not be able to change.
 
I believe u can only read boost on the hr meter with the stock guage? Need dash flash to get afr
 
TD max spool 17, BOV, 3 bar, CAI, 2.5” mod stock muffler.
1.5” track with 96 studs. Prior to this was running MS16 with stock muffler.
As mentioned , I ride with a buddy with exact same engine mods and track, but he has maxspool 17 without closed loop. He gets noticeably better fuel mileage.
Closed loop is supposed to do just the opposite. Have you compared or thought about the following? Clutching, belts, gearing, suspension, shocks, springs straps, transfer blocks can all have a effect on fuel mileage.. Weight of riding is also part of it…Extra wheels, larger rear wheels… You breaking trail and him behind you can be a big difference along with windshield heights, ride height and so on… might not be the tune or the closed loop at all…
 
I had been shipped a bad o2 sensor when I installed the CL in my 22 XTX. Sled ran good but had crazy erratic afr reading, would stay high for a long time on start up like a couple miles. Long story short I dealt with vendor reflashed time a couple times. Had terrible fuel mileage. Changed the o2 sensor and problem solved and mileage was more acceptable.might be worth a shot to look at afr reading. How much is the dash flash from TD might be the easiest way
 
Not to hijack, but have same issue, but using big pump aswell, and when I run lower power tunes I’ve gotten popping at midrange when I grab a handful of throttle. And I thought initially was spinning and rev limiter but more I played with it this weekend I think it’s just to much fuel. Bad O2 also I’m thinking for closed loop.
 
Does the closed loop turn off and default to the tune when the O2 sensor takes a crap?
Can the O2 sensor just give false readings, and if so is there a possibility for damage if it leans things out when it’s already lean and reading false values
 
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