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Engine Faults with MPI kit...

Chadly

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Every now and then I'm getting the Over Rev followed instantly by the knock message on the display on my sled. I am resetting the max rpm gauge everytime and the highest RPM I have seen is 7900 rpm so there is no way it's over revving per the gauge. Running straight 100 octane so knock seems unrealistic as well. Wondering if an over fueling issue would cause these faults because it sure seems like its running rich...
 

madmax

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Every now and then I'm getting the Over Rev followed instantly by the knock message on the display on my sled. I am resetting the max rpm gauge everytime and the highest RPM I have seen is 7900 rpm so there is no way it's over revving per the gauge. Running straight 100 octane so knock seems unrealistic as well. Wondering if an over fueling issue would cause these faults because it sure seems like its running rich...

How often you getting the knock code?
 
G

ghost rider

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Over rev can also be triggered when the rate of RPM increase is too quick. loading the primary quicker/harder takes care of that.
As stated above is probably what's happening. Happened to me last year a few times when the track came unloaded. I started last year with ski doo clutch components(only thing out there) and even tho I loaded it heavier with heavier ramp and heavier spacers it happened occasionally. I run 2 gallons of Av per tank and good non ethanol 93. This year I switched to sled head racing ramps(full clutch kit)loaded all the way and number 3 spacer weight, clicker 2 at 7-10,000 ft. I'm running around 8-8100 rpm at all elevations and conditions, up 4-5mph track speed to 52mph from 47ish. No blown belts and cooler clutch temps. Im at over 1000 miles on kit and in my opinion the best setup I've rode or ride with. Everyone can talk about how there turbo kit has ecu programmed or run a piggy back controller etc but if you don't have your clutching dialed it's all for not. Then you have the blend of fuel to deal with as well. To much race or Av and it feels lazy and rich and response goes to crap(once again doesn't matter which kit you have whether piggy back or programmed ecu) to little and you burn it down. I have no affiliation with any product manufacturer and have ran all there kits in the past. Loving my mpi 850 :face-icon-small-hap
 

pepperhouse

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As stated above is probably what's happening. Happened to me last year a few times when the track came unloaded. I started last year with ski doo clutch components(only thing out there) and even tho I loaded it heavier with heavier ramp and heavier spacers it happened occasionally. I run 2 gallons of Av per tank and good non ethanol 93. This year I switched to sled head racing ramps(full clutch kit)loaded all the way and number 3 spacer weight, clicker 2 at 7-10,000 ft. I'm running around 8-8100 rpm at all elevations and conditions, up 4-5mph track speed to 52mph from 47ish. No blown belts and cooler clutch temps. Im at over 1000 miles on kit and in my opinion the best setup I've rode or ride with. Everyone can talk about how there turbo kit has ecu programmed or run a piggy back controller etc but if you don't have your clutching dialed it's all for not. Then you have the blend of fuel to deal with as well. To much race or Av and it feels lazy and rich and response goes to crap(once again doesn't matter which kit you have whether piggy back or programmed ecu) to little and you burn it down. I have no affiliation with any product manufacturer and have ran all there kits in the past. Loving my mpi 850 :face-icon-small-hap
Happy to hear your mpi kit is working for you, tried to go that way but got tired of waiting and jumped on a silber kit.

When you say fully loaded with shr clutch kit does that mean your running the 5gram tungsten and 3gram set screw, 8gram total tip weight?

Which pivot bolt are you using?
The stock one or the 4 gram one in kit

Anyone on here have a weight for stock pivot bolt?
 

snoblind04

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I just weighted my stock bolt at 15.4 grams last years was about 17 grams.

I've got over 250 miles on my MPI turbo and it has run great, no codes or anything. I've run some pretty tuff snow and it has not missed a beat. Very happy so far.

I also switched to straight pump gas and I think it runs better than
 

rmk all the way

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I know my 850 absolutely hates having more then about 25 percent av gas and sounds like it’s loading up really bad on the bottom end


Sent from my iPhone using Tapatalk
 
Last edited:

madmax

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Over rev can also be triggered when the rate of RPM increase is too quick. loading the primary quicker/harder takes care of that.

That’s good info for anyone running a turbo on an 850. Had the same thing happen early in the season last year when I first got my mpi kit and was experimenting with clutching.
 
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