Does ethanol in petrol make it harder to start bike

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Hooli
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Re: Does ethanol in petrol make it harder to start bike

Unread post by Hooli » Thu May 07, 2015 12:52 pm

Coxy wrote: As an example of shelf life of Leaded fuels about twenty odd years ago a group of WW2 Aviation enthusiasts got wind that during the WW2 campaign in the Aleutian Islands running between Alaska and the Japanese archipeligo a number of Curtiss P 40 Fighters were abandoned, after a few weeks work they actually flew these aircraft back to the mainland, with the chemist they took with them testing the Fuel and Oils left in the Aircraft since WW2 and after checking for water in the Fuel one of the Aircraft was test flown on WW2 vintage fuel with no issues whatsoever then flown to another of the Islands where they had a modern Airstrip and refuelled and flown back to the mainland.
Any links to that? sounds rather interesting.
Classics ain't built in Metric

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hondapartsman
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Re: Does ethanol in petrol make it harder to start bike

Unread post by hondapartsman » Mon May 25, 2015 5:30 pm

As a small aside on this since replacing the genuine seal on my fuel cap with the one I cut out or nitrile rubber my fuel consumption has gone from low 70's to low 80's. It's to early to say whether this could be down to that, but I never remember the bike being that fuel efficient. Could the better seal be reducing evaporation of fuel in the tank? Our son in law complains about the petrol smell in his garage, so I wonder if he's noticed it's less strong. I'll keep an eye on this and report further developments.
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Notsospeedy
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Re: Does ethanol in petrol make it harder to start bike

Unread post by Notsospeedy » Tue May 26, 2015 6:25 pm

Surely, if it starts OK first time and only has problem with subsequent hot starts, then it can't be the fuel. If it was it wouldn't start first time either.

It may be the mixture being too rich for a second start but if it started already then the fuel is OK.

If you don't stop it, how long does it run before stopping itself?


Malcolm

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phil_h
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Re: Does ethanol in petrol make it harder to start bike

Unread post by phil_h » Fri Jun 05, 2015 1:27 pm

Hmm, sounds just like my iron velocette !

1. The 'tepid' start problem is usually attributed to heat-soak into the carb, causing the fuel to vaporise very differently when the engine isn't really warm but the carb is... and the ethanol will vaporise the fastest !
My 'solution' is to use as little flooding/choke as poss so as not to flood it.

2. Magnetos can only drive plug gaps of 25 thou - in open air all bets are a waste of time, you can only tell that its got something.

3. Faulty condensers in mags will cause just what you're describing.

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hondapartsman
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Re: Does ethanol in petrol make it harder to start bike

Unread post by hondapartsman » Tue Jun 23, 2015 8:42 am

As I said I'd report further about my fuel consumption with the home made seal in I can say now that the last three tankfuls have been high 70's to mid 80's so I think.the seal has an effect. Hopefully it also reduces the water getting into the mix as well. I'm thinking of trying the same with my other bikes as well.
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I'm like my regular ride, old battered and bit leaky, but still going.
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hondapartsman
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Re: Does ethanol in petrol make it harder to start bike

Unread post by hondapartsman » Wed Aug 12, 2015 7:24 pm

I see another thread about 'modern' fuel. As an update on my mpg though, still 80 to 85, although my other RS seems to manage only 60 to 65, but I can't make out why. The main difference between the two is a new Motad on the one with the lower MPG versus the composite Motad downpipes and Micron Silencer on the higher MPG one, but the two have always been different. Carb set up is the same, same model, same everything as such and both seem to run just as well although the one with the higher MPG is always revving harder to get the same speed. Which makes no sense either.
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Coxy
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Re: Does ethanol in petrol make it harder to start bike

Unread post by Coxy » Wed May 11, 2016 12:30 pm

HPM sometimes a lower geared engine actually gets better fuel consumption because it does not operate under as much load and carries it's speed easier with less throttle opening even though it sounds like it is working harder that is not necessarily so.

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hondapartsman
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Re: Does ethanol in petrol make it harder to start bike

Unread post by hondapartsman » Sat May 14, 2016 9:30 am

Maybe so but they are identically geared so maybe the tacho just reads a little out on it, everything on the bikes except the exhausts, and a few odds and ends are the same. The higher MPG bike has old C50 style indicators on with pointy lenses, but I can't imagine they make any difference even if they are slightly more aerodynamic than the flat fronts on the other, it has slightly higher wider bars on too ( off a sohc 750F2 as I could get those free at the time) Anyway that's now off the road and soon be stripped down so I can get it all cleaned up and refurbed a bit ready for another ten years of workhorse duties. I need to get new centre stand brackets on and put the original engine back in, it'll be interesting to see how what MPG it gets when it hits the road again. It would be nice to get the other up to those mpg figures that's a difference of about one ride to work and back between the two.
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supersix
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Re: Does ethanol in petrol make it harder to start bike

Unread post by supersix » Tue Jun 07, 2016 7:46 pm

My A65L can be a right swine to start hot. I spoke to a guy on a bike run up in the Peak District last year about a nifty little heat deflector/ insulator mod between the barrel and carbs on his A65L and he reckoned it cured the problem. Due to my normal manic lifestyle I have as yet had no time to mod mine! I think that gang of classic bikers were from Cheshire so possibly someone else from the area could have seen and photographed the bike. I did but my iPhone went TU shortly after and I lost the pics! :(

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