OUtlaw 500 pinging HELP

[mikegp]

I bought this thing new in 06 and ride alot I have noticed that the last few time Ive been riding it pings a full throttle or if i lug it.I run 91 octain fuel > 1st I checked plug ok 2nd I cam timing and valve clearance 3rd flywheel key 4th i checked Ign timing 45 deg advanced at 3500rpm not ok. I bought different CDI box timming now in spec 30 @3500>>>>still pinging I tried a richer than stock main jet (dyno jet) Im running uni airfilter,no airbox lid,baffle out of exhaust

[Bruce!]

First off, welcome to the board!

[blueline15]

i know this is going to go against convential wisdom and sound crazy, but your high octane fuel might be the culprit here, and this is why (assuming that this is a stock piston, stock compression)

so its pretty common knowledge that a higher octane fuel (i.e. 91) resist ignition from compression then a lower grade fuel (i.e. 87). octane also effects the flame speed, or how fast the fuel ignites from the spark plug. 87 octane has a faster burn speed then 91. what MIGHT be happening here is that the spark plug is igniting just before TDC, but the 91 is taking longer to burn through then the 87. so the piston has already returned or started to return before all of the 91 can be burnt, leaving excess fuel inside the cylinder unburnt, which is somehow igniting again, either from the hot exhaust gases or something else.

that kind of the advantage that vechicle use with FI and a knock sensor. the FI system is able to look at the oxygen content in the fuel and adjust fuel supply accordingly through the injecters, and if a car has a knock sensor it allows the ECU to either retard or advance the timing so that the fuel ignites at TDC.

if you use google, there are a few threads where people went from a highter octane fuel down to a 87 or 88 and the knocking when away. this has been a great debate for us at the shop since there are all types of theroies about what is going on here.

none the less, again, assuming stock compression is what you have, i would run the 91 almost out, put in 87 or 88 for a tank or two and see if the knocking goes away. its worth a shot and it certainly wont cause any harm to your machine running a 87 or 88....and you wont lose power because running 91 on a stock machine is not giving you any more power either

good luck....curious to see what exactly helps.

[mikegp]

I will try the lower octane fuel this weekend weather permiting.....Thank you for the input....This quad is all stock except listed add ons

[blueline15]

sweet, lemme know...doesnt hurt to run a lower octane, its a quick, easy, simple, and cheap way to either solve it or eliminate one variable. if it doesnt fix it then you can go back to 91 and we start over here. i personally run 91 in my sportbike, but the compression is low enough the min. octane is 87. so i understand you wanting to run 91, tends to burn a little cleaner. i have had no issue or knocking in 3 years on 91 octane on my bike though, so every machine can be different

[rotaxdave1]

If 87 does not work, uyou could always go the other way and mix in a little C10 or C12 and see if that shuts it up.

[mikegp]

Well after 2 weekend this is where Im at: Lower octane not it. I also tried this last week ,bigger jets up to the point of running poor. I also leaned it out to the point of running poor. Richer 180 jet no ping but quad wouldnt run for nothing. So I decided to go in deep: I took all plastic off . I checked valve timing OK.(why is the exhaust cam advanced). I checked valve clearance, the intakes were at .1mm spec. is .15mm got new pucks and adjusted them. I also decided to check every single electrical connection on this thing. OMG. they have so many all looked good with the exception of the rectifier square connection GREEN would be the color inside.......I cleaned good and put some dielectric grease in the connection... I hope to be able to run this weekend...wish me luck ..I will be running the rest of the 87 octaine and trying some 110 race gas...till later thanks for your help

[blueline15]

cant say you are not being detailed... im not sure what to say at this point. guess i be waiting for the update : )

[mikegp]

Ok well that wasnt the answer..The quad is better though it only pings at wide open throttle now..Cold or hot about the same.. The mechanic at the dealer said hes never seen this kind of problem before.. He did get me thinking maybe its not a ping it may be a internal noise or some thing like that..Do you think I should look in side?

[mikegp]

Well after looking in side and finding no evidence of pinging all looks great. I put the motor back in and problem went away on the first ride..Then on the next ride we started to hear it again. This time I could see the problem....Can u guess the problem...It was the stupid chain hitting the frame ..Im missing 2 teeth on rear sprocket The chain is bad and sprockets need replaced...boy do I feel stupid