I am wondering if some the issues I am having with starting the zilla is attributed to running av gas in it. I am mixing it 32:1 with Castor 927. It seems to be separating or not mixing completely. I even added some premium to the mix to help it break down better and mix more evenly. My head has been o-ringed and squish set so I have to run a higher octane.
Has anyone mixed race gas with premium and had better results. Any tips/ suggestions would be greatly appreciated. I am taking the bike to get dyno'd down in Oregon in a couple of weeks and would like to have some good fuel to run through it.
Thanks
Try the race fuel and see if its better. I too run 32:1 with 927 with race fuel no problem. I have not run av gas so I cant tell you how they compare.
Ive ran race gas mixed with pump gad wiyh no issuse but i will say if u store your fuel pump gas is bad bc it has ethanol in it and that will abosorb moisture from air and cause the pre mix to separate from the fuel.
I am wondering if some the issues I am having with starting the zilla is attributed to running av gas in it. I am mixing it 32:1 with Castor 927. It seems to be separating or not mixing completely. I even added some premium to the mix to help it break down better and mix more evenly. My head has been o-ringed and squish set so I have to run a higher octane.
Has anyone mixed race gas with premium and had better results. Any tips/ suggestions would be greatly appreciated. I am taking the bike to get dyno'd down in Oregon in a couple of weeks and would like to have some good fuel to run through it.
Thanks
Drain about a quart of fuel into a clean jar. Shake it up very well. If the fuel is crystal clear your fuel and oil are mixed at a molecular level. If the fuel is cloudy your fuel and oil are not mixed and will not mix until the temperature of the fuel is raised or the chemistry of the fuel is changed to one that is a good solvent for the type of oil you are using.
Cloudy fuel should not be run even after shaking. DO NOT TRY TO TUNE A CARB ON CLOUDY FUEL.
Cloudy fuel will turn crystal clear after the oil settles to the bottom of jar, fuel tank or float bowl. When it settles in the float bowl, the engine will try to run on pure oil. This may be why you have to keep kicking until you have consumed enough of the oil off of the bottom of the float bowl before the engine can get enough fuel to start.
If you get race gas make sure to check its specific gravity. 927 castor will separate in fuel with a specific gravity below .730. I'm not sure if mixing in 93 pump gas will prevent this separation and if it will what mixture to use. I plan on running Sunoco 112 and its specific gravity is .723 so I'm either going to research an acceptable mixture of 93 to keep 927 separated or I'm going to run AmsOil dominator synthetic.
If you get race gas make sure to check its specific gravity. 927 castor will separate in fuel with a specific gravity below .730. I'm not sure if mixing in 93 pump gas will prevent this separation and if it will what mixture to use. I plan on running Sunoco 112 and its specific gravity is .723 so I'm either going to research an acceptable mixture of 93 to keep 927 separated or I'm going to run AmsOil dominator synthetic.
Give all fuel and oil mixtures the "jar" test until you are satisfied that the type of fuel will stay mixed with the oil at the temperature you will be using the premix.
question... if the reasoning behind a cloud test is to get the fuel to be on a moleculor level or check to see if its mixed at the moleculor level. than you would also be checking different types of fuel & pre mix ratios, correct?
So, if you are worried about the oil settling on a premix of 24:1 to 32:1 with good premium race fuel shouldnt that effect your given compression ratio at a certain elevation also?
Or would you first determine the type of riding & elevation. Figure compression ratio, than perform the "jar" test to decide what fuel and at what premix to run..
or is all this just for running avgas and premium fuel mixed. i remember someone saying if the race fuel is mixed on the moleculor level than a % of pump gas should be added.
I appreciate all of the info. I will do the jar test here in a bit. I cleaned the carb again last night. I think you might be right about separation. There is residual oil on everything. I am pretty new to two-strokes other than the lt80 I put together for my daughter. It runs on a mix of 32:1 premium and Golden Spectro. I have had any problems so this is all new to me. Thanks
Well I emptied the tank, jar by jar just to see if there was difference in clarity. When I ran it through the reserve side of the petcock, the fuel came out real cloudy for awhile. I switched it over to the main side and clear as can be. it took a bit to drain, but the fuel overall was not mixed well. When I got to the very end, it was almost straight oil dripping. I then added a quart or so of premium to the jug and shook the heck out it for a bit. Poured some into the jar and it was real clear, cloudiness gone. Prior to starting I stepped up the pilot to a 30 from a 25.
I gave the bike 5 or 6 priming kicks and away she went. I shut it down waited a minute or two, rolled it over to TDC and gave it a good kick. She fired up. This is the fastest this bike has started. I think a combination of cloudy fuel and larger pilot helped greatly. I appreciate all of your feedback. This is a new arena for me so each thing is a learning experience. Thanks again and have a great 4th!
Rem...what kind of temps do you have in your area right now?
It has been upper 70's to low 80's the past week or so. I am going to pour some back in the jar this afternoon and see if it has separated again. I'm hoping not.
I am planning on heading to Florence in a few weeks and while I'm down there, I want to take the bike in and get it dyno'd. I just picked up an AAEN pipe and silencer for the bike from Heminutt. Hoping it will get here so I can get it installed and jetted for prior to going down. I really want this fuel issue to be resolved as well. We'll see what the jar test divulges today!
question... if the reasoning behind a cloud test is to get the fuel to be on a moleculor level or check to see if its mixed at the moleculor level. than you would also be checking different types of fuel & pre mix ratios, correct?
This is an old thread but I saw some questions that I think are very good questions and it may help some of you that have problems from time to time.
Any time you change fuels, brands of oil or fuel to oil ratios a "Jar" should be used.
If you are having starting problems, take a fuel sample directly from the petcock and give it the "Jar" test.
So, if you are worried about the oil settling on a premix of 24:1 to 32:1 with good premium race fuel shouldnt that effect your given compression ratio at a certain elevation also?
Or would you first determine the type of riding & elevation. Figure compression ratio, than perform the "jar" test to decide what fuel and at what premix to run..
or is all this just for running avgas and premium fuel mixed. i remember someone saying if the race fuel is mixed on the moleculor level than a % of pump gas should be added.
The oil ratio has nothing to do with what compression ratio your engine may need or riding style may need. The oil ratio your engine needs depends upon the length of time the engine is run at high RPM wide-open throttle at any given point during a ride or during a race.
The compression ratio that you run depends upon the rest of your build. You should run fuel with an octane rating that is a few points higher than what your engine package requires.
It is a common consensus among engine builders that you should always run higher compression at high altitudes than you would run at sea level. I do not agree with that statement. The high compression for high altitude theory is a carry over theory from the four stroke world and folk lore for the high performance two stroke world. I have found that just raising the compression ratio on a low altitude engine to try to turn it into a high altitude engine is laziness on the part of the engine builder and or shows a lack of understanding of the basic principles on which a high performance two stroke engine operates.
High altitude engines need a totally different build. That means that you will need different ports, pipe, head, ignition timing curve and carb to optimize the power for high altitude racing, not just raising the compression and calling it a high altitude motor.
Motorgeek, can changing oil type and mixture ratio help make you run richer or leaner? Say going from synthetic amsoil 25:1 to 927 castor 32:1? Does less oil, higher ratio mean more gas and a rich condition if your jetting was dialed previously?
Motorgeek, can changing oil type and mixture ratio help make you run richer or leaner? Say going from synthetic amsoil 25:1 to 927 castor 32:1? Does less oil, higher ratio mean more gas and a rich condition if your jetting was dialed previously?
In theory and internet folk lore, putting less oil in the fuel does richen the air/fuel ratio..................BUT............
oil is fuel and the heating value of most oils are so close to the heating value of gasoline it really does not hardly make any difference in the real air/fuel ratio.
The heating value and jetting can vary more from one brand of race gas to the next brand of race gas than changing from 25:1 to 32:1 premix ratio using the same brand of race gas.