Nasty yellow stuff!!!!!!

Discussion in 'Technical' started by monsterman, Sep 29, 2009.

  1. monsterman

    monsterman Ol'Timer

    routine cleaning out the fuel system on my ducati i came accross some nasty yello gluey deposits which appear to be from Gasohol also found the same stuff in my spare 25L JERRY can which has not been used much recently but has gasohol95 in it a viscous thick jelly like gloop smelling of gasoline but with a nasty chemical smell. Cleaned it up and alls well.

    When pouring fresh Gasohol into the bike I noticed it has an Orangy dye added .
  2. Loading...

  3. katana

    katana Active Member

    OMG !!!

    Eating Gasahol gives your bike cholesterol and clogs its arteries !!


  4. siinthai

    siinthai Ol'Timer

    Running a marina here in Phuket, I've come across plenty of issues with Gasohol...many unwarranted !
    Its a great excuse for many scaremongers....HOWEVER....
    It does NOT like to be stored...the issues being discussed here...
    And boats with fibreglass fuels tanks CANNOT use disolves the fibreglass...there is an additive which we are trialling which supposedly takes away the issues (claimed) of fuel line problems...
    Will post more on the additive, once we have more proof.
  5. Ian Bungy

    Ian Bungy Ol'Timer

    I Love these Reports on Gasohol. People with First Hand Reports and the Proof that Gasohol Has, Can & Will do Damage to Your Vehicle!!!
    Yet here in the Same Forum and Posts there are Still People Willing to Bleat on about How Good it Is and It Can't and Won't Do Damage :shock: Makes one wonder How Much Proof They Need :?
  6. monsterman

    monsterman Ol'Timer

    Totally agree Ian ..BUT we have to work with the damn stuff as its often all one can get.

    PICO-PICO Ol'Timer

    Does using 91 proper from time to time have a cleaning effect?

    If you got still some of the yellow sticky stuff could you put it in 91 for x amount of time and see if it dissolves .
    Does that make any sense?

    At least that what I do, every 1000km or so I switch to 91 for a few tanks.
    An illusion?
    My 600cc Silverwing is close to 70.000 95% on 95 Gashole, never any problem despite of heavy loads. However, never going faster than 100km/h.

    In other words, before the Gashole will show an effect, I need a new engine anyhow.


  8. brian66

    brian66 Ol'Timer

    Flushing with 91 petrol will not make any difference to cleaning any component of the fuel.
    The Alcohol content in the Gasohol will assist cleaning.
    Normal fuel (91 Petrol) is supposed to be refined until it is a combination of Carbon and Hydrogen molecules.
    The alcohol component in Gasohol is only different from the 91 petrol in that the alcohol component contains Oxygen in addition to the Carbon and Hydrogen molecules.
    The oxygen component of the alcohol is what makes it a very efficient cleaning agent due to it “oxidationâ€
  9. monsterman

    monsterman Ol'Timer

    Thanks Brian thats a very informative post .

    PICO-PICO Ol'Timer

    Very enlightening, thank you.
    This also suggests it doesn't make sense to use 95+G
    if the manual requires only 91.
    I guess out of insecurity I "spoiled my baby by feeding it more energizing 95+G"
    It is an illusion this would result better performance e.g. in the mountains. 91+G gives the same power output, correct ?
  11. brian66

    brian66 Ol'Timer

    Hi Pico

    Many people think that if they put the highest-octane fuel they can find into their engine, that they will have a fuel economy benefit or a more powerful motor cycle. If you have a high compression engine and you use a high-octane fuel, yes the motor will perform as it is designed.
    However, this not true if you use high-octane fuel in a low to medium compression engine.
    I will try to explain why without making it too complicated.
    The higher the octane rating of the fuel the harder the fuel air mixture is to ignite.
    The lower the octane rating of the fuel the easier the fuel air mixture is to ignite.
    A common misconception is that power output or fuel mileage can be improved by burning higher-octane fuel than a particular engine was designed for. The power output of an engine depends in part on the energy density of its fuel, but similar fuels with different octane ratings have similar density. Since switching to a higher-octane fuel does not add any more hydrocarbon content or oxygen, the engine cannot produce more power.
    However, burning fuel with a lower octane rating than required by the engine often reduces power output and efficiency one way or another. If the engine begins to detonate, that reduces power and efficiency for the reasons stated above and if allowed to continue will damage the piston and other engine components.
    If you are using a low octane fuel in a high performance engine you would notice that the engine was detonating (knocking or pinging) so bad at low revs or under load that it would feel like it has lost power. The engine was not performing at its designed parameters and was not igniting the fuel at the correct timing because the fuel could ignite too early.
    If the knocking was allowed to continue, the piston would fail first and the bearings would soon fail.
    The power output of an engine is mostly determined by the configuration of the combustion chamber, the compression ratio, valve timing, ignition timing and the amount of fuel and air that can be sent to the chamber to be ignited. There are other power gains to be made by reducing friction etc but they are in highly tuned engines.
    The density and ability of the fuel to burn completely when it is ignited is another contributing factor to the power output.
    A perfect combination of all the above will give the most power for a given capacity. The more air, fuel and then high compression of that mixture will produce the biggest force to push the piston down through its cycle and get high horsepower.
    The size of the engine crankshaft reciprocating mass, firing order and pistons will dictate the Torque output of an engine.
    Many high-performance engines are designed to operate with a high maximum compression, and thus demand high-octane premium petrol.

    A high performance sports motor cycle will have a much higher compression ratio compared to a motor cycle that is produced just for commuting.
    In all cases, the engine will perform at its highest output if the fuel air mixture can be ignited slightly before the piston reaches the top of the compression stroke. The resultant ignition of the fuel air mixture and expansion of the gases is what forces the piston down and creates the power output.
    A higher compression engine requires a much higher octane rating of the fuel to prevent the fuel air mixture igniting too early and working against the rising piston.
    A low compression engine will need fuel that will ignite more easily as there is less compression of the fuel and air to assist the ignition. Too higher an octane rating may prevent all the fuel to ignite and burn therefore you lose power plus unburnt fuel it discharged so you lose engine efficiency and money ‼
    If you ride at higher elevations, the atmosphere is thinner. Therefore, the amount of air volume and air pressure drawn into the combustion chamber will be reduced. Depending on how high up you are, the power output of the engine will be significantly reduced the higher you are. You need less fuel delivered to the combustion chamber to match the lower air volume and pressure. Because of the lower combustion chamber pressure, lower octane fuel is required if you were to permanently be at this high altitude.
    My knowledge of engine building is because I competed in road racing motor cycles for many years so I was forever looking to build high performance engines to get that edge over the competitors.
    I raced a Z9 Kawasaki in the late seventies. That particular bike came out with a compression ratio of around 8.5 to 1. Which is very low by today’s standards.
    at first, I ran that motor cycle on leaded fuel with an octane ratio of 98. I thought, as most young people who were racing at that time that high octane must mean more power.
    I soon learn I was wrong after I burnt holes in a number of pistons due to the lower compression ratio and the overly high-octane fuel. We retarded the ignition timing to stop the detonation but that just resulted in lower power.
    I worked that motor over and we raised the compression to 11.1 to 1. I was then able to use 105 octane racing fuel with a decent increase in power.
    I now own a 2009 CBR1000RR and a 2008 Yamaha R1. Both have a compression ratio of around 12.3 to 1 so you can see the huge difference in compression. I try to use 95 octane fuel in my sports bikes.
    I use 91 in my lawn mowers and my DZ 400 RM.

    Therefore, the answer to your question is.
    There is no benefit at all and some disadvantages if you run high-octane fuel in a low to medium compression motor.
    My advice to you is, you should run the lowest octane rated fuel that the motor cycle manufacturer has recommended.
    Look at the specification chart for your particular motor cycle and note the compression ratio. Always keep this figure in mind when you think about octane. The higher the ratio number the higher octane you need.
  12. trevbart

    trevbart Ol'Timer

    Cheers Brian, another very informative post ! Thanks for taking the time to explain in such detail.

    PICO-PICO Ol'Timer

    Brian, I am absolutely flabbergasted about the depth of your explanation and the ease with which you impart all this knowledge.

    David , I think the two posts of Brian ought to be prominently double pinned as


    PICO-PICO Ol'Timer

    Brian I owe you a fair share of the equivalent of the discounted value of my future higher petrol expenses. :D :)
    which certainly would have been substantial.

    I am running now on 91 + GASOHOL since about 1000km , certainly no power loss, I would say on the mountain even it bit more zappy. No strange behavior whatsoever.

    Compression 10.2:1 , however I checked this only after I did the riding.
    I don't bother about milage etc, just about riding fun.

    So when will you collect your debt??

    Cheers Pico
  15. brian66

    brian66 Ol'Timer

    I am glad to hear your bike is running just as you want and you believe you can save a few Baht on fuel costs to spend on other things.
    My advice helped you make that decision but the compelling reason that you now know about what fuel to use is because of the GT rider web site. Without this site, we would be restricted in our access to, or even void of answers to simple questions, such as when we are wondering if we are using or doing something with our bikes that could be unnecessary.
    I joined GT rider because I was impressed with the knowledge of people who wrote in and offered advice on so many things to do with riding and bikes in general.
    I have become and avid reader of GT Rider and I open and check the site many times every day of the week now.
    Some of the tips and advice in the posts of GR rider have been very helpful to me also.
  16. svenivan

    svenivan New Member

    Thank you Brian, very good information that will save me and other people money and make our bikes running better!

    :eek: :eek: :eek:
  17. monsterman

    monsterman Ol'Timer

    Pico, Brian is correct if your bike requires 91 and runs well on it ,using 95 will be a waste of money, but try running a bike that requires 95 on 91 and then the difference will be felt.

Share This Page