How long will petrol last in the tank??...

..before it goes all rancid and starts breaking stuff ??

I've only been out once in the last 3 weeks and didn't know whether that was a problem or not (apart from being super boring ).

Any idea's ??

Any other problems that could occur through lack of use ???

na its fine, i have left the SV before for a couple of month and it started fine and ran fine

You could always add some fuel stabiliser ...stops it going thick and also keeps moisture out ...be sure to run the engine for a while once you have added it to get it in the carbs/injectors ..I use Hondas own brand.

i read somewhere that petrol these days isnt as long lasting as it use to be ie the old 2/4 star.apparentley after 4/6weeks is when its suppose to start deteriorating,which is why some people reccomend fuel stabilizer if its gonna be stood for a while.although in saying this i know people who just leave it as it is and it seems fine so really its down to what you think.

From my race car days, the biggest problem we had with old fuel, would be reduced octain levels. This is not a problem in it's self, but in high compression engines it can lead to poor performance (Less hourse power), Should last around 6-8 months in the tank max, If it is older than this then it will damage your engine, blocked Carbs/injectors. Stabalisers and octain enhancers all help. If you are going to leave a bike stood for more than 5 months I woudld drain the tank.

Just go and fill your tank before you put it away for Winter, it will be fine

Originally Posted by sv-robo

... after 4/6weeks is when its suppose to start deteriorating,.

And of that how long has it been in the petrol stations tank already??

Fuel will 'work' that is greater than 6 months old, even a year, but at tat point you start getting other problems like gummed carbs (if the bike hasn't been run).

As stated fuel is best in its first month, but I wouldn't worry too much after 3. Presuming your tank is 1/2 full, just top it up with nice fresh 'super' unleaded to bring the octane back.

That said I have issues with getting 'fresh' super (I don't think the turnover is as quick as normal, so it could have been sat in the tanks for months already???), so if it were me I'd just top it up with normal unsplendid.

A bigger problem is probably carb gumming/sticking and getting damp in the tank ... that'll make it go rusty inside ... open the lid and spray WD40 in there

Originally Posted by dickis01

From my race car days, the biggest problem we had with old fuel, would be reduced octain levels. This is not a problem in it's self, but in high compression engines it can lead to poor performance (Less hourse power), ....

That is not entirely true ... octane isn't there just for power, it is to stop pre-ignition (pinking) on a race engine they run super high compression, therefore they are at greater risk of pre-ignition. Pre-ignition can kill an engine BAD ... from burnt out valves, to holed pistons, to bottom end failure ...

My bike race engine would only run high octane fuel (still pump fuel - but 'super' only) ... I evidently bought a bad batch once and within 1 days use (~20 mins) it had burnt the valves out ... as I had bought the fuel (Optimax) at great expense from a petrol station the day before, so I can only put that down to it having sat in the petrol stations tank going 'stale' before I bought it ... lower octane ... rogered valves ... big repair bill (had only just had the engine rebuilt!!) and loss of power for the weekend affecting my results ..

Hence my previous statement about trying to find 'good' (fresh) super ..

The CBR6 had been standing for a year or so before I started it up again. Luckily it fired second press of the button and revs/ticks over cleanly, but I've seen the horrors of what broken down fuel does to a set of 600 Diversion carbs. It took 2 whole days to clean them out.

I'll be filling the tank up with fresh fuel soon to dilute down the stuff that's in there and then adding stabiliser to the mix. If you're thinking of doing the same, don't forget to run the bike for about 10 minutes to get some of the stabilised fuel into the carbs or injectors.

Originally Posted by Blue_SV650S

My bike race engine would only run high octane fuel (still pump fuel - but 'super' only) ... I evidently bought a bad batch once and within 1 days use (~20 mins) it had burnt the valves out ... as I had bought the fuel (Optimax) at great expense from a petrol station the day before, so I can only put that down to it having sat in the petrol stations tank going 'stale' before I bought it ... lower octane ... rogered valves ... big repair bill (had only just had the engine rebuilt!!) and loss of power for the weekend affecting my results ..
..

There are only about 5 or 6 BP stations in the UK that supply extra high octane super unleaded fuel - I can't remember how high the grade is. We always use it in Danny's ZX10R race bike because the rules allow for any freely available pump fuel and also because we have one of the suppliers just down the road in Milton Keynes. It ain't cheap, but Danny notices the difference in power if we have to use normal super-unleaded.