Fron what I have been told, by several recognized engine builders. Elevation plays a large role as to what octane can be run with a high comp piston. For me, my elevation is approx 500-900' above sea level. Therefore, if I run a 10.5-1, It will be border line of running 1/2 race and 1/2 premium, but may be possible to run prem pump. If I go up to 11.-1 or higher, 100% race fuel is recommended by all of the builders I spoke with except one. This is what I have been told by several nationally recognized atv engine builders such as Powroll, FST, Trinity, Bike Worx and a couple others. I too, am looking for more serious and reliable power from the Raptor. From what I am being told, there is a huge difference in power from 10.5-1 to 11.-1, but I personally don't really want to run 100% race fuel. Cost and inconvenience are two reasons to think about.

Just my thoughts and what I have been told. Hope this helps.

 

i talked to powroll the other day (I GOTTA ADMIT THAT LADY KNOWS HER STUFF!)

I was told that 11:1 WILL require race gas

NOT good pump gas
NOT good pump gas with an octane booster
NOT aviation fuel
PURE RACE GAS ONLY

the reason being was that since it's such a big bore being a 660 you'll notice it MUCH more than a small bore with high compression.

So now I am just wondering what to do. Do not want the inconvenience of needing race gas. She also told me that 10:1 would not make a difference only 11:1 would. hmmmmmmmmm what now?

 

what's everyone going to do?

today I went to a local dealer who was going to order my bikeworks 11:1 piston kit and he too said that in a single cylinder 660 at 11:1 you would HAVE to run ONLY race gas.

I am ready to tear into mine to do a cam and piston, does ANYONE have anything lower than a 11:1, supposedly 10.5 :1 will be ok on 94 octane


I can't be the only one thinking about this, come on guys!!!!! whats our options?

wiseco won't have anything out for a month
powroll is not selling their race cam now due to they need to make heavier valve springs.