Did not expect this

[compo z1r]

I ran my LC on Avgas, not sure on the specs today but back in the early 90's it was high lead content 100 octane petrol, The LC loved it.

Still the same high lead put lead in ya pencil
Or 100 LL low lead
My mate runs it in his RC30 race bike and he has a light aircraft too and I’m only 3 miles from breighton air field a
Non of this filling station Shite E10

[moizeau]

It was the 100ll I used, apparently still far more lead content than the old 4 star.

[Al]

With the carbs all in bits i ordered 4 new 'O' rings to seal the float needle valves. Genuine Mikuni parts from Motocarb for a little over £11 delivered. http://www.motocarb.com/ There has been some intermittent dribbling (bike not me) and difficulty setting the fuel heights correctly for some time and two of the four float needle valves just fell out when the holding screws were removed so the 'O' ring seals wernt doing their job any longer.
All four came off the needle seats like 100 year old wood. Three are about ten years old and one was replaced two years ago with a complete new valve because the spring plunger had broken.
The three older ones were very perished and showing signs of fatigue.

Picked up five litres of Aspen 4 yesterday from a local lawnmower shop. Set about finding out what it is and how it compares to petrol.
Taking into account that i am no chemist, reading spec sheets and searching the internet appears to show that the specific gravity / density is similar but lower than vehicle petrol. ie. it is slightly lighter / less dense than vehicle petrol.
Note. There are different versions of Specific Gravity (API or otherwise) and the method for testing is not always quoted when notifying the SG
The bowl float: will ride higher in a more dense liquid (shut off sooner) and lower in a less dense one (shut off later). If changing between liquids with what is an essentially fixed (Temporary but of course adjustable) float height, a less dense liquid level would expect to be higher ie. override the float more easily. Its not a hugh amount, but the reason this has been of interest to me is because of the intermittent weeping and trying to track down the cause. I use the bike in all corners of the UK (ocassionally Europe) wherever i find myself and cant necessarily pick and choose what the ethanol content or RON will be.
When there was five star about (not the band) fuel contained many of the lighter fractions which are now being legislated out and forecourt petrol was less dense as a liquid for that reason. Fuel level heights quoted in manuals etc. for older vehicles would have be based on lighter / less dense liquid fuels. Perhaps more similar in ways to AVgas.
The upshot for me is: no i wont be setting my fuel levels at this moment using Aspen4 as was my plan ahead of putting standard pump fuel back in it for the season. I will have to wait.

AL

[rickm]

That's very interesting, thanks Al.
I'd never really considered that the SG of different fuels would vary enough to make a difference to the float height and fuel cut-off level.

[Al]

I doubt it does make a great deal of difference. There is about 1 or 1.5 % difference between the two as an average of the values quotes for SG in different loactions and taken at different temperatures, humidities, altitudes, methods etc etc etc.
I was trying to find a tiny explaination for a small problem and perhaps i should have moved back and looked more for the obvious.
If you put ethanol in the picture and its affinity for water, at 5% by volume and that part of water which is miscible in ethanol then it becomes a very different story!

AL

[moizeau]

Just a quick report back.
https://english.bardahl.fr/en-us/our-pr ... stabilizer
Been using this for a while now in all engines with carbs. It says compatible with E10 so that's what I've been using. Cheap (well not really atm) supermarket fuel.
No issues so far including the little diaphragm carbs on the chainsaw etc.

[warren3200gt]

Most of the treatments for road vehicles only works for 6 months even when used at the higher levels on the label.
I've swopped over to using treatments for marine engines as they work for twice the time period for much the same money.

They assume that road vehicles are used fairly frequently and as such longevity is not required.
Often boats don't get used for a year or more so it needs to work for at least a year.

[Al]

I put 25% 'Aspen 4' in my tank with a capful of ethanol killer and went to Snetterton for two days three weeks ago. Could not detect any downsides at all. No hesitation, stumbling, stalling, fuel leaks, lack of response or power etc etc etc. That said; i was a little distracted because two years ago to that week, i binned it in a big way there and ended up in hospital
I think the shelf life of 'Aspen 4' is 3 years so will have no hesitation running the tank and carbs out, and putting a half litre through them for this winters' layup.

AL

[moizeau]

The Bardahl reckons 2 years. It certainly did it through the winter, highlighted by the way the chainsaw and mowers started at the start of the season.

[Bps]

I have been using Star Tron in my fuel for last 6 years without any issues including on occasion E10 fuel where not able to get Esso and it’s not been started for several months.
I choose star tron as in USA it has good reports from boat owners and grass mowers where they don’t use them in winter period.
I think it claims to help stop water separation from ethanol and prevent gum up in carbs etc.
It is available in UK and suppliers can be found on Amazon.

[Mr Bump]

Hopefully not stating the obvious here, but this regime has worked for me:

I own 4 - 5 bike usually, newest at the moment is an '04, oldest was until recently a '77, usually all in use in the summer. What I do (and it is a faff admittedly) is use the bikes regularly so the fuel in the tank never gets too old, or drain the tank and carbs completely when the bike is parked up for the winter or longer, then use the drained fuel in a winter bike, lawnmower, camping stove, whatever.

This works for me (so far) and Ive never yet had any problems with carbs etc after Ive sorted them the first time (if necessary) and lined the tank (if necessary).

Is it worth considering how the water is getting in there? Do you pressure wash around the tank cap, transfer fuel from a can that has had condensation in it, store the bike in a place that goes through lots of temperature changes (like if you heat the garage in winter before you work in there) which might encourage condensation in the tank? My stuff lives in a well ventilated unheated garage that does get a damp wall in winter but the stable temps and airflow seem to keep condensation etc well under control.

Happy to admit I might have been lucky so far and that bacterial contamination looks horrible - I would be an unhappy chap if I found a carb full of it.

Ive seen similar cases at work on diesel that has sat in truck auxiliary fuel tanks for a long time. Maybe if you happen to pick up a germ it spreads through your fuel if it's left 'stagnant', and the diesel storage tank these tanks were filled from had the bug in it, but it didn't affect fleet cars etc that also ran off the same tank but used the fuel up quickly.

Olly