The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Adrian on October 07, 2011, 03:24:55 AM
-
Hi there - I'm trying to find some accurate info about the use of Ethanol mix petrol. My 1984 airhead has Bing Constant Depression carbies and I'm worried about the effect of this fuel on the diaphragms. Ethanol mix fuel is becoming widely available here in Oz and in one state it's all you can buy. I have found conflicting info and of course the petrol companies say it's safe to use. However the bike press strongly recommend that it is NOT used in "plastic" petrol tanks. Where do I go to get an accurate answer. I currently use Premium Unleaded (98 octane) only because the bike runs really smoothly and more easily - particularly with a passenger onboard and when travelling thru the Adelaide Hills. I balance my carbies as soon as the bike starts to feel a little rough. Thanks for any help you can supply...
-
I have found conflicting info and of course the petrol companies say it's safe to use. However the bike press strongly recommend that it is NOT used in "plastic" petrol tanks. Where do I go to get an accurate answer.
I wish there was a definitive answer to this question. Most information seems biased one way or the other.
A few facts that can't be disputed -
Adding ethanol to fuel lowers the overall calorific value so maximum power output and fuel consumption suffers. Maybe not by much but it's a fact and it should be reflected in fuel prices. Governments seem to be plain dishonest about this.
Ethanol causes definite issues with plastic/fiberglass fuel tanks but they can be internally coated with something in a similar way to lining steel tanks.
Life of some rubber parts like fuel hose is shortened unless they are of a type rated for use with ethanol.
-
This is interesting because I've been told that because of the lower compression of our engines that higher octane is not necessary; all that will do is blacken the plugs with no apreciable increase in power. From your experience Adrian, this is not so.
I had the top ends of my motor done up recently & was told that I should drop in some lead replacement on every fill. I've just started doing that. (A capfull from a $20 bottle will last quite a few fills).
As an aside, I'm still running the motor in so nothing over 4000rpm so lot's of running in traffic.
Over 300km's it still only used 16.5 litres.
-
Hi Graeme - I must admit that the plugs are darker in colour (brown - black combo) but when the carbies are properly balanced they never go black. If you're getting 100k's plus per 5litres then thats comparable with my old girl. Around town I get about 18 - 20 k's a litre - up in the Adelaide Hills at higher speeds and a lot of up and down that consumption stays about the same even two up. On "flat" highways I get about 22 k's to the litre. These bikes are pretty consistant when they're properly tuned. But now I m confused. I've always used unleaded - the hand book says this is okay. I've just checked my Haynes workshop manual and that says unleaded is NOT okay. Oh well I'll be pulling the barrells off in the near future as part of the current sprucing up exercise so I guess I'll just have to check the valves etc for myself. Nice to hear from a fellow Aussie ....
-
This is interesting because I've been told that because of the lower compression of our engines that higher octane is not necessary
Not sure what compression your engine is or what octane your fuel is but the original European models with 9.2:1 compression bikes really prefer 98 RON fuel. I have to retard the ignition a little to get by on 95 RON fuel without pinging. The compression later dropped to 8.5:1 which would be fine on 95 RON octane. I think that compression change happened at different times for different markets.
I think the whole unleaded/valve seat recession debate was overdone at the time lead was phased out. There hasn't been problems to the extent that was forecast. My valve clearances don't seem to close up at all between checks. As long as that continues I'm not going to worry about it.
-
Thanks Barry - I'm thinking of replacing my fuel lines during this strip down sprucing up I'm doing at the moment. Here in Oz the fuel is significantly cheaper than standard - that is when you fill a 60+ litre tank on a car. By the way we pay about $1.34 here per litre. Thats about .85p in English money.
-
Regarding octane, the rule is simple: use the gas with the lowest octane that doesn't cause pinging. Anything higher than that is wasting money. (But if it makes you feel secure, there is no doubt that that has a certain value.)
Here in California, we've had nothing but E10 for years. I find that I get about 10% lower fuel mileage in all my bikes, compared to when I'm out of state and burning pure gasoline.
E10 is hard on fuel lines and plastic floats. It may also cause premature death to carb diaphragms -- bad news for those with the flattop Bings.
The other thing to keep in mind about E10 is that ethanol is hygroscopic and will pull water out of the air. It also evaporates out of the gasoline more easily. This can leave water at the bottom of your tank. Since I ride my bikes year round, I don't worry about this too much, but if you put your bike up for the winter, try to use a gas stabilizer and fill the tank as high as is practicable; or else, empty it completely. By minimizing the headspace in the tank, you slow the evaporation and reduce the amount of humid air from which the ethanol can draw water.
One reads about the problems with the Ducati retro classic bikes that have plastic tanks, and also Norton fiberglass tanks. But the plastic tank on my R1100RS never had any problems. It seems to be very material specific.
-
I'm assuming this will be the case for California, as the fuel we get in Aridzona, is the blend used in California, but I've read that E15, 15% ethanol content fuel, is not too far off in the future .
-
Bob, there were a bunch of reports a few months ago about how the US EPA had approved E15 for sale to use in autos and light trucks beginning with the 2007 model year. They specifically said it was not approved for older vehicles and all motorcycles, ATVs and personal watercraft.
Of course, how many gas stations are going to stock E10 and E15? E15 is definitely something that will be in our future, and experience will tell, as it has with E10, what bits in our older bikes we need to watch.
-
It may also cause premature death to carb diaphragms -- bad news for those with the flattop Bings.
Darryl
Why only bad news for flat top Bings. I would have thought all OEM diaphragms were the same rubber type.
-
I change my rubber fuel lines every couple years, keep the carb float bowls dry when I'm not riding the bike for more than a week, and try to keep either fresh gas in the tank (if more than a month or so old I use it in the lawnmower) or if putting the bike up for winter months I use ethanol specific fuel stabilizer in the fuel tank, and run it through so that it gets into the carbs (drain carb bowls into snowblower gas tank afterwards). Sometimes I just take the bike fuel tanks off and bring them into the house (empty) where it dry for the winter.
-
Okay guys thanks for all the info its been interesting and informative .....
-
Here in the Phoenix, Aridzona area, we've had E10, or 10% ethanol content fuel since 1994, I personally have not seen any issues with the vehicles that I have due to ethanol in the fuel .
I work with a bunch of mechanics here at work, most do their own auto maintenance and I have not heard of any chronic problems with fuel system component degradation due to alcohol in the fuel supply .
If you have a marginal ignition system, you will most likely have problems in cooler weather (55F., 13C. and lower) with the first cold start of the day .
-
E15, great, haven't the green-weenies driven up food prices enough turning all that corn into gasahol? Now they want to skim off a few million more bushels that could have went into my corn-flakes!
-
Or into a little sourmash for a little more Jack Daniels finest !!!!!!!
-
Here in the Phoenix, Aridzona area, we've had E10, or 10% ethanol content fuel since 1994, I personally have not seen any issues with the vehicles that I have due to ethanol in the fuel .
Hi just wanted to clarify this with you. When you say "vehicles" I assume you mean your bikes. I'm happy to just use whatever is available so long as I can trust it not to damage my Beemer. Thanks.....
-
That's what we're saying - we haven't seen anything bad come of it besides higher gas prices, less power and worse gas mileage ...as if that's not enough.
-
I don't know if other countries other than the US, had MTBE (methyl-tertiary-butyl-ether) added to the fuel supply as an oxygenating agent in the mid '90's, but word was that it was going to destroy rubber fuel system components in older vehicles .
I have not heard anything about this either, MTBE has since been removed from use, as it was found in underground water samples, from leaking storage tanks at fuel stations, pipelines, etc......
I was born and raised in the Chicago area, 5% ethanol was added to the fuel back in the mid '70's and continued until I left there in '93, never saw a problem with fuel system rubber components failing prematurely .
Progress isn't it a wonderful thing !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D
-
Okay thanks guys - when the inevitable happens here I'll have confidence to use it .....
-
It may also cause premature death to carb diaphragms -- bad news for those with the flattop Bings.
Darryl
Why only bad news for flat top Bings. I would have thought all OEM diaphragms were the same rubber type.
Exactly so, but with the flat tops, the diaphragm is only available with a new slide.
-
E15, great, haven't the green-weenies driven up food prices enough turning all that corn into gasahol? Now they want to skim off a few million more bushels that could have went into my corn-flakes!
It's not the "green-weenies" -- they hate it too, for just that reason. You can thank ADM and all the legislators from the corn states, who love the subsidies and the resulting higher prices for corn.
-
Darryl's post about diaphragms does not apply to UK. I bought a pair for my flat tops from Motorworks recently. They installed on the slides with no trouble.