Fuel in my bike is from September 2022
Discussion
I was under the impression UK fuel lasts for at least a year before going off but the sources I've read say 6 months. I don't believe I added a fuel stabiliser to the tank (the tank is brimmed).
Due to circumstances I've barely been able to ride the bike since then, in fact I'm only getting it MOT'd today just to give it a run and make sure everything still works as it should but I likely won't even get enough miles in to use a whole tank.
Should I drain it or will it be OK if I add something like this:
https://www.amazon.co.uk/Genuine-Briggs-Stratton-A...
The bike is a Suzi C800 (C50 to the Americans) so it isn't a highly strung performance engine at all, but does use EFI
Due to circumstances I've barely been able to ride the bike since then, in fact I'm only getting it MOT'd today just to give it a run and make sure everything still works as it should but I likely won't even get enough miles in to use a whole tank.
Should I drain it or will it be OK if I add something like this:
https://www.amazon.co.uk/Genuine-Briggs-Stratton-A...
The bike is a Suzi C800 (C50 to the Americans) so it isn't a highly strung performance engine at all, but does use EFI
Tribal Chestnut said:
As long as it’s not a particularly old bike, I’d not be too worried.
2005 reg, but they still sell the same bike now with minimal improvements to the engine. I dont even think the new model has ABS/TC either. It's a basic V twin with lenient tolerances. Some of the rubbers are probably on their way out though, surely. Year old fuel will have definitely lost some octane and drawn in some water however as you brimed it hopefully not too much
At that age it's borderline, you might get away with it you might not
Personally I'd probably give it a go taking it easy if it starts playing up I'd drain three quarters of it - I typically stick it in my lawn mower which runs on anything
At that age it's borderline, you might get away with it you might not
Personally I'd probably give it a go taking it easy if it starts playing up I'd drain three quarters of it - I typically stick it in my lawn mower which runs on anything

With fuel injection it'll be fine, one of my cars went 18 months stood not being used with a full tank and was fine when I started using it.
If you do leave it for a long time, brim the tank with higher octane fuel (low ethanol or zero ethanol) so there's no room for condensation to form. And don't use stabiliser, it's only for low power engines with carbs, most of them don't even work anyway.
If you do leave it for a long time, brim the tank with higher octane fuel (low ethanol or zero ethanol) so there's no room for condensation to form. And don't use stabiliser, it's only for low power engines with carbs, most of them don't even work anyway.
I think you'll be OK too.
What fuel is it? If you have super of any brand its more likely to be OK.
If you have super Esso its almost certainly fine. I've also seen normal Esso has very low ethanol content.
If you have standard supermarket I might be tempted to drain it if I had garden tools I could use it in.
What fuel is it? If you have super of any brand its more likely to be OK.
If you have super Esso its almost certainly fine. I've also seen normal Esso has very low ethanol content.
If you have standard supermarket I might be tempted to drain it if I had garden tools I could use it in.
I've started bikes with 5 year old fuel before!
It will be "fine" but at the same time it's not going to run that well vs fresh fuel.
The modern stuff will start to go off from about a month old now....that doesn't mean it won't run, just it will increasingly not run as well.
Given the type of bike I wouldn't overly worry (it's hardly a highly strung sportsbike) but if you're not going to do enough miles to empty it then a year old fuel isn't desirable and is best syphoned off and used for the lawn mower. Then replace it with super.
It will be "fine" but at the same time it's not going to run that well vs fresh fuel.
The modern stuff will start to go off from about a month old now....that doesn't mean it won't run, just it will increasingly not run as well.
Given the type of bike I wouldn't overly worry (it's hardly a highly strung sportsbike) but if you're not going to do enough miles to empty it then a year old fuel isn't desirable and is best syphoned off and used for the lawn mower. Then replace it with super.
As everyone else has said, you will be fine, particularly if it was brimmed. I often leave my bikes sat for 6 months plus, not always with a full tank and the only time I ever had even the remotest idea there was an issue was 2 year old fuel in my zx6r which took a little longer to start when warm! Ran fine though!
My usual approach is to run older fuel down to about half way and then top up with fresh fuel, then just refill and run as usual. I always try to top off with low/no ethanol before putting away again.
Ultimately the problem isn't the fuel loosing "potency", its water collecting in the fuel through ethanol absorption, water is the enemy in fuel systems. Ethanol will pull moisture out of the air which in a sealed tank is a fixed amount, the more full the tank the less air and subsequently water available.
Finally worth noting as well that just because a fuel is marked as E5/10 etc doesn't mean it contains that much, its "up to" for ethanol content.
My usual approach is to run older fuel down to about half way and then top up with fresh fuel, then just refill and run as usual. I always try to top off with low/no ethanol before putting away again.
Ultimately the problem isn't the fuel loosing "potency", its water collecting in the fuel through ethanol absorption, water is the enemy in fuel systems. Ethanol will pull moisture out of the air which in a sealed tank is a fixed amount, the more full the tank the less air and subsequently water available.
Finally worth noting as well that just because a fuel is marked as E5/10 etc doesn't mean it contains that much, its "up to" for ethanol content.
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