RMK DET issue

[kurtis.g]

Had a MNTK fix kit installed and a aftermarket head. Since my sled runs good, But at lower elevations like the trail ride up to the cabins in McBride or Valemount my sled throws a det code when I open the throttle up a bit. once I'm up in the alpine I can go WOT with no issues. I'm wondering if anyone else has had this issue with a fix kit? one theory I have is with the fix kit theres a little more power and im over revving and it throws a DET, another is maybe my compression is too high and im actually getting detonation.

 

[TDR]

I’ve been through this before. Watch your revs down low cause it’s easy to hit det on the trail with the extra hp. My sled would rev enough to hit the rev limiter, det and shutdown. The high compression head and fix kit provide more hp.

 

[kurtis.g]

yeah that's what I do, Im wondering if i can change up my clutching I hate having to limp up the trail

 

[TDR]

Then you might suffer at elevation. The trail up is only the conduit to the fun zone!!

 

[ABMax24]

Your aftermarket head bumped compression increasing the chance of detonation. If you want to run WOT at lower elevation you either need to drop compression, retard timing (don't recommend this as it negates the power created by the higher compression head), or run higher octane fuel. Adding 5 liters of race fuel or av gas per tank should be enough to keep DET at bay, and don't even be tempted by the 94 octane pump gas as it will have significant amounts of ethanol added to bump octane ratings, and ethanol poses a whole other set of issues for 2-strokes.

 

[kovs]

Have to agree it’s fuel couple gal of av or race should solve issue
Used to run a stage kit on pro and with fuel controller and nitrous. It would just keep pulling rpm with good fuel. Maybe fuel map bumped up numbers to 9200 rpm helped?
On spray here in sask racing it would turn 87-8800rpm. Don’t think they are rpm limited like Doo @ 8600

 

[skegpro]

Any chance of something else creating a vibration frequency similar to that of the ping from detonation?

https://youtu.be/0xI94ZDF54Y

 

[Chrisco]

ABmax24 Is right on the money, bump up the octane a bit and good to go.

 

[skegpro]

ABmax24 Is right on the money, bump up the octane a bit and good to go.

Chevron 94

 

[Rbrduk]

Chevron 94

Chevron 94 has ethanol in it.

 

[Jorg Jorgenson]

Only gas I trust in my sled is shell 91.

 

[skegpro]

Chevron 94 has ethanol in it.

Not anymore it doesn't.

 

[Rene G]

Not anymore it doesn't.

What about Petro 94, anyone know if it has ethanol?

 

[TDR]

Lots of ethanol. Shell 91 is best.

 

[Ryeser]

A bit of AV gas when you ride down low and you will be good to go... I get my AV gas at Villaneuve...