so your saying 93 octane is ok for 12.1? That seems a little wrong [img]i/expressions/face-icon-small-wink.gif[/img]

maybe 10.1 - 11.1 --93 is fine


I dont think a 12.1 will run without some pinging going on w/ 93

 

My YFZ450 has a sticker on the tank. 91 octane or better,and compression is 11.9 to 1. I have run 89 octane(all i could get on the trail) and it didnt ping but power was not right.

 

I rode a guys bike last weekend that is over 12/1 and he was running 92 in it with no signs of detonation. Compression ratio isn't the only factor in determining the octane rating.

 

Cannondale built the FX400 at a true 12.5:1 and recommended 93/94 for it - no probs.

Mine is closer to 11.5-11.8:1 stock and I'll be running that same 93 or 94 ... and I'll run the same when I get the 12.5:1 piston. I guess the Dales didn't have detonation probs as bad as some can or do.

 

Gee,I was told to use unleaded 98,in my motor(its still stock).Is that not right then?

 

On what?

I doubt anything stock requires that much octane.

 

On a Raptor,the lowest I can get here in Spain is unleaded 95,should I be using that?

 

Im running 11:1 in my Wolverine and I filled it up with 92 and put that 104 octane boost in it that you buy in the red bottle and I dont know what octance it would be now 104? I heard the engine get unusually louder one time when I hammered down on it, how can I tell if its detonating or not?

 

The highest octane boost would raise your octane level is 7, so you would be running around 99. With 11:1 you could run straight 92 and shouldnt have any problems

 

Thanks Crotts, I wasnt sure how well the fuel additives worked because i never had to deal with them before.