93 octane! 10% ethanol!!!! : (

[agurdo17]

as far as gas goes this winter there just is no practical way to not get the 10% ethanal in my gas. I am running a 04 pro x2 800 and my gf is riding my 01 xcsp 600. Is there anything i should be doing to the gas to make sure it will not effect my motors or is it already safe.

Some people always add things to their gas some people dont. Ive heard people put polaris 2 stroke oil in their gas, marble mistery oil in their gas and other things. is there anything that will work to combat the ethanal and is it really that big of a deal. Specialy with detonation in the 800. The 600 also has a hot seat cheater head on it that is designed for pump gas.

 

[BIGGDAWG]

if you know you will be running ethanol you need to richen up your jetting.

can't remember exactly but it is 1 or 2 jet sizes. will check and get back with ya.

 

[likinit2]

We have had ethanol gas here in Michigan for a few years now. With that said, getting the deto tuned out of that 800 is possible and with the ethanol in the fuel is not a problem, just keep it fresh. The biggest problem with the ethanol blend is that it absorbs water. That is also a good thing because you don't need to be as anal about adding dry gas to keep the gas flowing. I went with a twin pipe head and was able to lean things out at sea level and it has NEVER run better. I advanced the timing as well and I am running my needle in the #2 position and just richen up the airscrews setting to comphensate and added only a half turn to the fuel screws. It gets great mileage, instant throttle response and doesn't run hot and idles down nice when you come up to a stop. I have 12000 miles on this with only a piston and rings freshen up at 8000 miles. an slp single will yield about the same results as the head, as the stock pipe at sea level is a little tight for the 800 and you can tune the deto out of that 5500-6000 range. also running light springs in the ves so you are not keeping those valves closed any more than they need to be.

 

[agurdo17]

ok thanks. in the past couple years here non ethanol gas has been harder and harder to find. last year they made a regulation that every gas station has to apply by a certain date. My 800 would detonate on one tank of gas and run like a champ on the next one. The only way i could get it to not detonate to often was by putting 93 in it and running the key in the 87 position.

I jetted my sled twice last year lol but depending on which gas was in it changed the jetting. Will have to just stick with the ethanol i guess as that is the only way to be consistent. Also the xcsp has 7K on the motor with the cheater head. i have the stock one also and just bought the sled. wondering if it is in my best interest to go back to stock?

 

[BIGGDAWG]

found this on the web but most consensus is for E-10 you need t increase your jetting by 5-10 percent. ethanol is an oxygenated fuel so it runs leaner and need more fuel to do the same work.

Getting the Correct Fuel Ratio Mixture:
The main factor in converting a regular spark ignition fossil fuel engine into flex fuel engine is to get the fuel mixture correct. Ethanol contains roughly 30% less BTU’s than regular fuel and requires more fuel to be injected into the engine to get the right stoichiometric conditions. Stoichiometric ratio is the proper ratio of the air to fuel ratio to cause complete combustion. A normal car will run this mixture slightly rich to get the best mileage with least amount of engine wear (an engine running above this ratio will overheat and ruin the internal combustion parts). The correct stoichiometric ratio for regular unleaded gasoline is 14.7:1, while 9.7:1 for E85 (and can be any value in-between for different alcohol/fuel ratios). In newer cars, this means either holding the injectors open longer to get extra fuel into the engine, or running a higher flow rate injector. In carbureted engines, this means re-jetting for a higher flow rates. Newer flex fuel cars are already designed for these large changes in flow conditions and can automatically re-jet for the various fuel/alcohol ratios (they usually use the exhaust O2 sensor and various other sensors to determine the correct fuel to air ratio mixture). In older cars (even ones with injection systems as late as last year), the computer box and injectors cannot hold the injectors open long enough to get a rich this mixture with the E85 fuel. In Brazil and other countries, this problem has been circumvented by using a special box that plugs in-between the computer and the injectors, and causes the injectors to be held open longer (Figure 2). You could also install a larger set of injectors, but then the vehicle might not run correctly if you have to go back to regular fuel.

 

[BIGGDAWG]

also found this

Enleanment: Enleanment is a legitimate issue for certain two-stroke, high performance engines, such as snowmobiles
and chainsaws. When gasoline containing oxygen is used in an engine with a fixed jet carburetor, the air/fuel mixture is said to
be “enleaned”; that is, a greater ratio of oxygen to fuel enters the combustion chamber. The result is that the fuel burns more completely, engine RPMs increase,
there is a greater power output as well as increased exhaust temperatures. Enleanment also happens when either the air temperature or the operating altitude
decreases, since both factors cause air to become more dense and increase the oxygen content per unit of volume. Snowmobile manufacturers recommend
changing to a larger fuel jetting when altitudes drop more than 1,000 feet, the operating temperature drops more than 30 degrees or an oxygenated gasoline is used. Reality is that most engines are set at the factory to operate slightly “rich” and don’t need to be adjusted until two or more of the above mentioned factors are realized. in any event it is best to know your engine and occasionally check your spark plugs for a light tan color to determine whether
the operating temperatures are within a safe range. Plugs that show black carbon deposits have been running excessively rich while white plugs indicate a lean
condition and higher operating temperatures.

 

[Bump]

I had made it a point to never run anything less than 93 oct and NO ETHANOL in my sleds while I was living in MN. Now that Im back in ND, its a little tougher, but was still possible until last year.

Last season I had no choice and had to fill in small town, ND. The only thing they had was 87 oct with 10% Ethanol. I didnt even make it back to town (30 miles) before it blew up. (02 Pro-X 440) Havent re-built it yet, but would like to make it able to run on low oct w/ ethanol as thats all the little towns around here carry!

 

[agurdo17]

i hear ya on that one. that sled didnt come with a detonation sensor right? when did they start using them. 03-04

 

[likinit2]

That is my point, I went with an anti deto lower compression head. It is a RK tek low elevation twin pipe head. The stock head is a lousy design for oxygenated fuel. It didn't hurt the power any, I was able to drop 2 jet sizes and tune out the deto in the midrange. I always run premium or the deto is still there in the 5500-6000 range. I was hoping I could run regular but I still get the deto even with the key swtch in the reg position. I will be trying some slp #530 low elevation twin pipe cheater heads on a buddies sled and see if the results are the same. The SLP head looks to have a little wider squish band than Kelseys head. I would have bought another RK tek head but they are no longer available. I know they work........ BTW, I was able to add a couple grams of weight to the clutch weights. I did advance the timing but that was it. I'm running 10-68's and a brown epi 125/280 and it pulls like a freight train.