Petrol in a bike how long is it good for?

[McCabe-Thiele (Ted)]

I recently had an issue with old petrol (SUL) causing a misfire in our Merc - it had half a tank of fuel that was left over from October 2020 when I last filled it up to the brim. Luckily I have managed to save the old petrol after adding some Octane reviver from Halfords- once I am close to reserve I will put new fuel in the tank - (the misfire then went within a mile or so of driving).

I did a bit of internet research where advice varies for petrol stored in a vehicle quoting an optimum shelf life of between 3 weeks -
6months.

This got me thinking about winter storage & what do folk here do if their bikes are only ridden in the summer months - my worry would be that if the tank is drained over winter then there is a risk of tank rusting?

Any comments / advice / observations welcome.

[Nurse Julie]

Drain tank and swill round inside with diesel, this stops the rust by leaving an oily coating. Before that, run bike, whilst running turn fuel tap off, bike will eventually stop running, carbs are now empty. If you want to be super sure, put some Redex in the tank with the existing fuel, do as above, the carb internals will also be very protected. Fill tank with fresh fuel in the spring and away you go.

[SumpMagnet]

Modern petrol is awful stuff for keeping.

The ethanol evaporates off, whilst also attracting moisture from the air....so it basically ruins itself, then goes to work on your tank to rust it out.

If a bike is in daily use, it'll be fine, but if you are laying it up for winter, you don;t want any fuel anywhere. Plus, of course, you'll want to buy some fresh in the spring.

[ka-ja]

For a long storage, I use the drain plugs to empty the carbs. rather than just run them dry, I have seen the "rot" that long term that modern petrol residues can cause, even to alloy and brass in some cases.

[K2-K6]

Ted, I don't routinely fill up cars if not intending need for journey, also happy to run them right down to zero-ish to use fuel and refresh as convenient to general use with family travelling.
We've local filling stations/supermarkets with very high turnover which may help with fuel dating and their tank storage for condition etc, don't use anything special in the way of grades to avoid E either.

We've a 1991 V8 petrol with injection system that I'm running with 1% castor oil continuously since E10 has been around, no problem experienced with that and perception of no water attraction with this (I've static samples sitting in jars to assess mix effects and dropout)  also don't mind carrying a can to run tank out to clear or run risky range with contingency.  This one is plastic tank but system is clean as a whistle (I can get into top of tank for inspection to see if there's anything in there) but generally all good.  Cap is sealed on this one with carbon filter and air/emmisions containment fitted.

Perception, I'll emphasize that, is that E fuel is more stable with oil added in low ratio, castor smells nice too.

[Laverda Dave]

Ted, I don't routinely fill up cars if not intending need for journey, also happy to run them right down to zero-ish to use fuel and refresh as convenient to general use with family travelling.
We've local filling stations/supermarkets with very high turnover which may help with fuel dating and their tank storage for condition etc, don't use anything special in the way of grades to avoid E either.

We've a 1991 V8 petrol with injection system that I'm running with 1% castor oil continuously since E10 has been around, no problem experienced with that and perception of no water attraction with this (I've static samples sitting in jars to assess mix effects and dropout)  also don't mind carrying a can to run tank out to clear or run risky range with contingency.  This one is plastic tank but system is clean as a whistle (I can get into top of tank for inspection to see if there's anything in there) but generally all good.  Cap is sealed on this one with carbon filter and air/emmisions containment fitted.

Perception, I'll emphasize that, is that E fuel is more stable with oil added in low ratio, castor smells nice too.

The 1% castor oil sounds like one of those Edd China top-tips Nigel, I'm going to try that in my bikes. Where do you buy the castor from these days, I used to buy mine on a Thursday night at Wimbledon Speedway but haven't seen it around for years even at Kempton Park.

[McCabe-Thiele (Ted)]

It's on e bay under cosmetics.

[K2-K6]

Dave, the supply I've used is this https://www.amazon.co.uk/Castor-Oil-litres-Pure-Pressed/dp/B06WVD519M/ref=asc_df_B06WVD519M/?tag=googshopuk-21&linkCode=df0&hvadid=344355771029&hvpos=&hvnetw=g&hvrand=11054008386220214821&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9045909&hvtargid=pla-685207637751&psc=1as just a pure castor oil.

Not being used for primary lubricant (for that you'd need a proprietary motor specification) but as mitigation in E fuels. I most definitely don't believe in "miracle" products in this field and don't believe this can do that. To make it clear, soft material incompatibility like rubber and seals etc being vulnerable is not something that can be accommodated with an additive in my view, making that aspect something to consider separately.  But with separation from storage and ability to reduce potential metal corrosion within fuel systems, then this tentatively appears to offer performance advantage.
Castor has extensively been used in alcohol fuel with methanol and has no problem mixing with this and petrol. My static samples held for some period of time seem really stable.

And so, some potential to consider but I'd encourage others to make their own evaluation to assess this seperate to my observations.  Adding 10ml per litre of petrol will give a start ratio of 100/1 making it easy to try it. Even at 15ml giving 75/1 it can't be seen smoking, but with enhanced smell.

Definitely something to consider for those interested.

[McCabe-Thiele (Ted)]

Could Castrol R be used as an alternative ?

I used to put it in my Petrol back in the 1960's just for the aroma!

.https://www.ebay.co.uk/itm/164815605316?chn=ps&norover=1&mkevt=1&mkrid=7101533165274578&mkcid=2&itemid=164815605316&targetid=4585169652812021&device=c&mktype=&googleloc=&poi=&campaignid=412354547&mkgroupid=1305120599331881&rlsatarget=pla-4585169652812021&abcId=9300541&merchantid=87779&msclkid=d1cc6372cf691cd57ad101aff048ae61

[K2-K6]

Could Castrol R be used as an alternative ?

I used to put it in my Petrol back in the 1960's just for the aroma!

.https://www.ebay.co.uk/itm/164815605316?chn=ps&norover=1&mkevt=1&mkrid=7101533165274578&mkcid=2&itemid=164815605316&targetid=4585169652812021&device=c&mktype=&googleloc=&poi=&campaignid=412354547&mkgroupid=1305120599331881&rlsatarget=pla-4585169652812021&abcId=9300541&merchantid=87779&msclkid=d1cc6372cf691cd57ad101aff048ae61

Yes Ted, it's the same base oil in that product.

Castrol is effectively named after "castor oil" by contraction of the two words. History of "Castrol" is the company started as CC Wakefield  making oil products for machinery, research led them to using castor oil as base to build motor oils because of it's most substantial characteristic (it's structure is really hard to break down under pressure, making it a very resilient lubricant with high shear properties) being ideal to keep moving components from wearing each other during use. Ultimately so successful that CC Wakefield was rebranded as Castrol.

The R in the name of "Castrol R" is not as many suspect meant to denote Racing, but of it's origin in "Ricinus" oil (also the potential origin of Ricin poison) which brings that R to the party. Poisons in other beans are arsenic in broad beans and kidney beans too, the subversive little boogers 

The castrol R product will contain other elements to make it specific to engine lubrication, components to control ph, zddp etc likely. Cost is much more than cosmetic plain castor and those components are not needed for this topic I believe. It's more that at 1% addition it's effectively 10% ish of ethanol content in E 10 fuel and so may have a significant binding effect with the E component to reduce it's attraction of water. Speculative yes, but seems to offer potential.

[Oddjob]

They used to use Castor oil in WW1 aircraft, however the fumes used to give the pilots the shits , so much so that after a lot of missions they had to hose out the cockpit.

Think of people behind you sucking in all that diluted castor oil, do you really want to make them shit themselves? 

[mike the bike]

I went on a 130 mile round trip on the 400.  Going over the mountain,  it  lacked power to the extent that I put off an overtake.  Not like me at all,  I overtake most things.  I'm wondering if it's that E10 shite I filled up with.
Had anyone else used E10 and ground it lacking in power?

[taysidedragon]

They used to use Castor oil in WW1 aircraft, however the fumes used to give the pilots the shits , so much so that after a lot of missions they had to hose out the cockpit.

Think of people behind you sucking in all that diluted castor oil, do you really want to make them shit themselves? 

A lot of the early WW1 aircraft had rotary engines which flung out neat oil and the airflow blew it straight backwards into the pilot's face. A much bigger problem than burning castor oil at 100 to 1. The clowns sitting in metal boxes with filtered air won't even notice. 😁

[Oddjob]

At least they were regular. 

[K2-K6]

https://youtu.be/fs3a5qT3k18