Honda-SOHC
SOHC.co.uk Forums => Anorak's Corner => Topic started by: Johnwebley on July 03, 2020, 10:13:26 PM
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As the new petrol has added oxygen.
Do we need to enrich the mixture?
Guessing raise the needle one groove.
Maybe that is enough
Or hotter running plug.7 to an 8.
I would like comments from the clever guys.
Those far knowledgeable than me.
Thanks
Sent from my SM-A750FN using Tapatalk
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Doubt it, aparently bigger problem will be starting
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Doubt it, aparently bigger problem will be starting
I understood E10 is 10% biofuel,so in a litre 900cc is petrol,100cc is ethanol,
ethanol is oxygen rich,so it will help the burn,and already have 10% less petrol in the mixture
should we consider maybe increasing the main jet? and lifting the needle one slot ?
not to worried about the 500,but the 200 ,and my 125 RD twin both seem sencetive .
and it looks like we loose a few horses as well,
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The attached article from the latest Honda Owners Club magazine suggests that "older engines run better on ethanol blended fuels".
However there are other the issues to consider regarding rotting of some rubbers and plastics as well as the corrosive nature on metals if any moisture is present in the fuel system.
https://www.dropbox.com/s/kvwblhhg0mc9qxa/Ethanol%20Fuel%20Issues.pdf?dl=0
The article relates to a book: Classic Engines, Modern Fuel - The Problems, The Solutions. I was interested in getting a copy to help me get to sleep 😴 but it must be popular because it appears to be sold out in all the places I've looked.
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I am the Technical Editor for Complete Kitcar Magazine and a few years ago I researched and wrote an article n the problems and solutions for the E5 fuel which was just being introduced at the time. Obviously with the introduction of E10 fuel these problems will be exacerbated.
There will be a slight weakening effect due to the extra oxygen included in the fuel mix but at 10% ethanol the standard settings should still be OK. The bigger problems are the corrosive effects of the oxidation and hydration products of the ethanol on metals and the way it attacks the elastomers in the O rings and flexible fuel lines. These effects will be even worse in vehicles stored for longer periods of time.
The FHVBC, at around the same time, did some independent research into the commercial fuel additives supposed to combat the harmful effects of the ethanol on the metallic components. Not surprisingly many of them were completely ineffective but they did find a handful that worked. This information is still available on their website.
Personally I use Ethomix from Frost Restoration and I drain the fuel system before I lay my bike up for the winter. These additives only protect the metal parts so you also need to look for biofuel compatible rubber hoses too.
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As the new petrol has added oxygen.
Do we need to enrich the mixture?
Guessing raise the needle one groove.
Maybe that is enough
Or hotter running plug.7 to an 8.
I would like comments from the clever guys.
Those far knowledgeable than me.
Thanks
Sent from my SM-A750FN using Tapatalk
To comment on the mixture specifically;- Working with AFR (air fuel ratio) to hopefully give a concise view, petrol without the additional ethanol has a stoichiometric ratio (complete combustion of all fuel by ratio to air mix) of 14.7 to 1 , after which point there's too much air to match the fuel content. Most engines of the era we are concerned with don't run anywhere near that figure, more usually the standard jetting is more like 12.5 to 1 and richer than ideal.
E10 fuel has an equivalent of 14.04 to 1 taking into account the mix of components. The mixture if just left alone clearly now has a position closer to the stoichiometric value ( effectively making the combustion process leaner with this fuel).
A pragmatic approach is that the shift is just under 5%, and as the original factory jetting was running effectively too rich constantly, it's realistic to consider this as a desirable shift. It shouldn't, if the original setup is competent, give us any problems. But if you are concerned about it, a shift of one notch on the main jet needle could be assessed.
I though favour changing the spark plug heat range by going upwards one (ngk numbering) so 7 to 8. I don't do this because of conventional reasons of "running hotter" that is often inaccurate when used to suggest this.
I view it as the small resultant changes in effective jetting run a cleaner combustion process, and so reduces the demand for trying to keep the plug tip hot enough to make sure it doesn't foul.
In other words, you can take advantage of the change if effective fuel ratio and run the combustion closer to optimum.
An advantage of running a higher heat range plug is that it's more resistant to any affects of detonation (loss of control of the burn phase) and reduces the overall risk to the engine of consequence associated with this.
I've been doing this with an old car engine for some years which we've used in France, and commonly on E10 without any problem. Closely related in metallurgical terms to these bikes ( all aluminium construction with pushed in steel barrels, two valve per cylinder, offset spark plug, 9.35 to 1 compression etc) and as some of the linked comments suggest, it does run more efficiently on this fuel. General setup has been good for measured emmisions too whether E10 or not.
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Personally I use Ethomix from Frost Restoration and I drain the fuel system before I lay my bike up for the winter. These additives only protect the metal parts so you also need to look for biofuel compatible rubber hoses too.
Interesting comments and I bow to both your and K2-K6’s knowledge and expertise.
I’ve ordered some Ethomix to give it a try. The description suggests that this is a good additive to combat the corrosive effects of Ethanol in fuel and it’s reassuring to know that it is endorsed by the FBHVC.
Do you know what biofuel compatible hose materials, apart from Viton, would be recommended and are readily available?
Ian
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To comment on the mixture specifically;- Working with AFR (air fuel ratio) to hopefully give a concise view, petrol without the additional ethanol has a stoichiometric ratio (complete combustion of all fuel by ratio to air mix) of 14.7 to 1 , after which point there's too much air to match the fuel content. Most engines of the era we are concerned with don't run anywhere near that figure, more usually the standard jetting is more like 12.5 to 1 and richer than ideal.
E10 fuel has an equivalent of 14.04 to 1 taking into account the mix of components. The mixture if just left alone clearly now has a position closer to the stoichiometric value ( effectively making the combustion process leaner with this fuel).
A pragmatic approach is that the shift is just under 5%, and as the original factory jetting was running effectively too rich constantly, it's realistic to consider this as a desirable shift. It shouldn't, if the original setup is competent, give us any problems. But if you are concerned about it, a shift of one notch on the main jet needle could be assessed.
I though favour changing the spark plug heat range by going upwards one (ngk numbering) so 7 to 8. I don't do this because of conventional reasons of "running hotter" that is often inaccurate when used to suggest this.
I view it as the small resultant changes in effective jetting run a cleaner combustion process, and so reduces the demand for trying to keep the plug tip hot enough to make sure it doesn't foul.
In other words, you can take advantage of the change if effective fuel ratio and run the combustion closer to optimum.
An advantage of running a higher heat range plug is that it's more resistant to any affects of detonation (loss of control of the burn phase) and reduces the overall risk to the engine of consequence associated with this.
I've been doing this with an old car engine for some years which we've used in France, and commonly on E10 without any problem. Closely related in metallurgical terms to these bikes ( all aluminium construction with pushed in steel barrels, two valve per cylinder, offset spark plug, 9.35 to 1 compression etc) and as some of the linked comments suggest, it does run more efficiently on this fuel. General setup has been good for measured emmisions too whether E10 or not.
An excellent explaination, thank you. My experiences echo this, I've toured Europe for years and used the E10 fuel as soon as it was introduced over there on my 40 year old bikes, with no detrimental effect to running. There is the obvious corrosion effects but the question was mixture/fueling.
The one thing I have found over the 35 years of running my old bikes, from when they were not my old bikes, they were new, is the fuel consumption has steadily gone up with miles (104,000 on one and 86,000 on another). This obviously means mixture has slowly got richer as carbs have worn, so the E10 fuel has definitely made them run better.
The rich mixture is so bad on one bike I am now changing carbs and refurbing the originals.
My point is, as above, I think most old bikes will have the same issue as mine, rich running, so E10 fuel will be ok.
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Do you know what biofuel compatible hose materials, apart from Viton, would be recommended and are readily available?
Ian
[/quote
Personally I use this.
https://www.ebay.co.uk/itm/100-BIO-Fuel-Hose-Petrol-Pipe-Ethanol-Butanol-Methanol-Diesel-Cohline-R9-R6-R10/251182149018?hash=item3a7b9f6d9a:g:PNkAAMXQn11RffRU]
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Personally I avoid regular fuel like the plague.... premium fuel for your classic is the easiest way to avoid 10% ethanol.....for the time being at least.
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I have just had to replace the fuel lines on my 550, they have lasted just over 2 and a half years. That is around 1200 miles.
The lines had disintegrated into a slimy sticky mess with chunks breaking off. This is bog standard fuel line bought from local motor factors.
I’ve used it dozens of times over the years on classic cars and bikes without any issues at all.
Also I always turn my fuel tap off about 1/4 mile from my house. I’ve got it down to a fine art now so the bike dies as I get into the drive, so there should not be any fuel sitting in the lines but they have still gone bad.
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Very odd...modern fuel line should withstand modern fuel.... :o
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Personally I avoid regular fuel like the plague.... premium fuel for your classic is the easiest way to avoid 10% ethanol.....for the time being at least.
Fully agree. Ethanol fuel is Hygroscopic and will lead to internal corrosion of old steel fuel tanks. I assume modern fuel tanks have corrosion proof finish, perhaps zinc to avoid this issue with ethanol.
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Here's a link to a list of compatible materials.
https://s41.photobucket.com/user/gtmdriver/media/Biofuel%20Safe%20Materials_zpsychuz2sf.jpg.html
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Brass and Aluminium listed as not suitable?
So as well as fuel lines, rubber and plastic parts failing the carbs themselves may take a hammering?
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Personally I avoid regular fuel like the plague.... premium fuel for your classic is the easiest way to avoid 10% ethanol.....for the time being at least.
Me I only buy Super Unleaded as I always do until they fiddle with that as well. Apparently there is a loss of economy using E10 so it seems an odd way to reduce emissions.
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Ethanol has a higher octane rating than petrol, it burns cooler and completely, as it is an 'oxygenate' (the fuel contains oxygen molecules.). It also has a lower energy content, around 30% less than petrol, and it should make an engine run more smoothly, but slower and do fewer mpg.
Good for destroying rubber components in the fuel system, especially old bikes!
Ethanol is cheaper to produce than petrol, but we never see reduce prices at the pump!
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As far as fuel hose goes I find that the only stuff that seems to be ethanol proof is the genuine Honda stuff that DS sells.
It's also the correct inside diameter of 5.5mm for our bikes and has the right wall thickness to prevent kinking when routing around the carbs etc.
It's not cheap though.
https://www.davidsilverspares.com/950015500160M
The same stuff is standard fitment on my Honda lawn tractor, which I suppose is intended to be ethanol proof for todays fuel.
Hope this helps
Regards
Skoti
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All the pipe we buy from Planet Silicone holds up very well to modern fuels and its really cheap from them. We have also been upgrading all O rings in the carbs to Viton for a long time now and no problems there either.
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Hi Julie,
thanks for posting the tip regarding cheaper fuel hose and carb viton 0 rings.
I previously tried 6mm silicone/neoprene based hose from Louis Motorrad (which wasn't cheap) but is was supposed to be ethanol proof.
After a couple of years it turned rock hard and I had to cut it off the fuel tap fitting with a stanley knife.
Turned out that it was only rated for use up to temps of 100°c. I've noticed it's no longer stocked by Louis.
Do you have a supplier for the correct size viton 0 rings for the float bowl drain plugs?
regards
Skoti
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Hi Skoti. I hold stock of Viton O rings for the drain plugs, but if you are wanting them for your 750 F2 I'm not sure if they are the same size as all the other drain plugs. Do you know the size? PM me if you wish.
Should have said, if its a F1, I have definitely got stock of the correct size.