Guess what cured my deceleration knock??

[forgiven]

I put pure gas in...remarkable. The bike ran awesome. I know some may have said it but I would have never believed it could make that much difference.

Thought I needed a new piston and rings. Expensive gas just saved me some money!

[gassergrant]

Originally Posted by forgiven

I put pure gas in...remarkable. The bike ran awesome. I know some may have said it but I would have never believed it could make that much difference.

Thought I needed a new piston and rings. Expensive gas just saved me some money!

I notice it when I use our (98) super unleaded to our normal pump stuff, I never run on 95 ron even in my track car its 98 or 99 ron stuff

[twowheels]

I've recently found a 90 octane no-ethanol source. No need for the octane, just had to get rid of the junk in the fuel.

[Jakobi]

BP Ultimate 98RON here most the time.. Not unusual to have to refill at half time in a sleepy little town though.. Go for the best they have which is typically only 95RON

[(F5)]

Originally Posted by forgiven

I put pure gas in...remarkable. . . .
. . .Thought I needed a new piston and rings. . . .

I guess running without oil will save money in the short term. . .

[webmaster]

Where to find gasoline with no ethanol blended with it - in U.S.

www.pure-gas.org

jeff

[Coop]

Originally Posted by webmaster

Where to find gasoline with no ethanol blended with it - in U.S.

www.pure-gas.org

jeff

I've looked at that before. Not one place in Pa within a 3 hour drive of my house. My only hope would be to buy race gas and I can't afford that.

[bkwdc]

http://pure-gas.org/index.jsp?stateprov=PA

[Caravan Monster]

In the UK, ethanol quantities in fuel are dictated by our overlords in the european union. The current rule is that the average over all fuel sold is 10% ethanol. In practice, this means that the fuel retailers aim to add more ethanol to diesel and less to petrol, as it is more harmful to petrol fuel systems. An online search suggests the following fuels are currently ethanol free (do your own research et c.):

BP Ultimate Super Unleaded (except S.W, England)

Esso Super Unleaded (except S.W. England)

Texaco Super Unleaded

No ethanol currently added to Total Petrol (except NW and SE England)

Murco ethanol free

In the humid British climate, one of the problems with ethanol is that it is hydroscopic - attracts water. I am told that this is a particular problem with plastic tanks and am in the habit of emptying fuel back into a metal can as part of the post ride clean up routine. I also drain the carb, which is a p.i.t.a. We' ve all seen what happens to a float bowl if it's left for a long time with fuel in it. The resultant goo when ethanol combines with water isn't very clever in jets and is a real nuisance in things like chainsaw carbs, where it can easily stop diaghpragms and fuel pumps working altogether.

To go back to the O.P., ideal air / fuel ratios for pure petrol (14.7:1) and ethanol (9:1) are substantially different, so at 10% ethanol, a bike set up for pure petrol is going to be running lean. As I understand it, ethanol specific engines use a larger volume of fuel to acheive the same output. I know that my Dad's historic racing cars that run on methanol, which are like big go-karts with 500cc singles, need twin float bowls to supply enough fuel to the engine and fuel consumption is something daft like 6 miles to the gallon. It is also telling that they aim to completely empty the fuel system within 15 minutes of getting into the pits.

I'll save my rant about 'bio' fuels used to dilute diesel for another time. In a country where a pair of F.I.M. enduro tyres cost the same as a tank of diesel for my panel van, you can guess I'm not happy about the continual fall in quality and increasing price of fuel here