Gas Question

VectorBoy · Post by **VectorBoy** » Sun Jan 17, 2010 10:36 pm

I know this is a dumb Question but I was wondering what you guys are running for fuel in the V-max? I have a 83 thats all stock. 92 octane? Thanks

Joe · Post by **Joe** » Sun Jan 17, 2010 11:12 pm

I'm, running 92 octane E10 pump premium.

I had to go up two jet sizes for the E10 blend.

E00 is $5 a gallon and I have to take time off from work to drive 20 minutes to get it during working hours.
E10 is $3 a gallon and is available 24 hours a day one mile from here.

Post by **tyler440** » Sun Jan 17, 2010 11:29 pm

i actually started running 93 octane from citgo.... im not sure of the exact reason but it made my sled not want to rev out.... i went back to standard 87 and it revs fine with exhaust temps maxing out around 1230*F (usually about 1150 at WOT tho)... temps were actually falling off at WOT with the 93 octane, the longer i held held it the further the right side went down... for me im just going to run the 87 and watch the egts and plugs

chrisrider63 · Post by **chrisrider63** » Mon Jan 18, 2010 8:22 pm

Thats because regular gas has a bigger bang then the higher octanes, like so many guys have taught me on this site and what I tell everyone else- you dont need to spend alot of money to go fast.

Bob Vehring · Post by **Bob Vehring** » Mon Jan 18, 2010 10:56 pm

Just to keep this straight before someone gets hurt, Its not quite that simple.

Multiple things come into play here. First, by itself the octane rating does not make more power. It allows you to make more power if you decide to do certain things to your engine, or, if the factory did them for you. The octane rating is simply a way to measure the fuels ability to resist detonation. It does this mostly by having the flame front travel slower.
Now, when either you, or the factory want to increase the power in an engine, two of the common ways are to advance the timing, or, increase the compression ratio.There comes a point when doing either or both of these, that the engine now needs a higher octane rating to resist deto.
Jetting and ambient temp also play into this.Rich is safe but costs HP. Lean is fast but if you fall over the edge, you lose, usually a piston.

So lets think over a few things;

You usually ride in 20 - 30 deg temps, now, its -10, you might be near the edge

You usually fill up at popular, busy stations, but now your out in the middle of now where and the only station has enough water in its tanks for fish to live, you might be near the edge.

Maybe the gas stations two counties over has more alky in their gas..............

Some people use the cheap old petroleum based oil, or maybe there's some Bean oil (Caster) purest left, those can leave, over time, enough carbon on the piston and head to raise the compression,...............

The point here is that if several of these things stacked up on you, you could pass the point were 87 octane gas is safe, even if that's what you normally use. That doesn't mean you have to change to 93, it just means think about conditions and know your engine.
It never hurts to carry a can of octane boost in the trunk.

Post by **tyler440** » Tue Jan 19, 2010 8:39 am

i have alsways ran 87, but after 4 years off running my sled i finially read the sticker on the inside of the gas door and it says to run 92 or better.... i thought "whoa maybe i have been flirting with disaster all this time" so i started using 93.... also at the same time i install my egt gauges... i was seing temps around 1125 at the highest and the right cylinder would drop to 800 after about 5 secs of WOT... also the plugs were getting a bit lighter than i like to see.... switched back to 87 and now im seeing temps just short of 1200 and no fall off at WOT... runs like a dream and my plugs are starting to regain thier brown color... im not sure of the exact chemistry behind everything, all i know is it loves 87 and hates 93.... at least from that gas station.... im might try some "contains ethanol" gas next and see what that runs like (ya know if our snow comes back....)

agfirecat · Post by **agfirecat** » Wed Jan 20, 2010 8:40 pm

i didnt know we could get non ethanol fuel anymore other than race gas. every station in my area sells e10 should i be jetting up for it i remember years ago rejetting for the oxygenated gas everyone was blowing pistons back then.

Post by **tyler440** » Thu Jan 21, 2010 8:29 am

im not sure about the gas in our parts... one gas station says "Contains Ethanol" on the pump where as the others do not.... im not sure if they are required to put that sticker on the pump or what... maybe the rest have ethanol too they just dont have a sign on the pump... beats me

eavery · Post by **eavery** » Thu Jan 21, 2010 10:32 pm

i know marine engines do not like ethanol it plugs the filters and injectors it's ben a big issue around my parts nobody likes to have there jet ski or salmon boat stall out 10 miles or better from shore do to the fuel sluggin up

so most marina's have straight gas no ethanol marked on there pumps no other gas stations around me sell straight gas it all contains 10% ethanol