Petrol degradation to tar!

[Skylark]

Not quite a boaty subject...........please indulge me

My road bike has been off the road for 3 years. It's only a summer use toy and I've had 3 good sailing seasons (there, now it's boaty!). Or should I say "my outboard motor has been unused for 3 years"

The petrol in the tank has degraded and separated and it's left an almost tar like residue. The tap was completely blocked and nothing, other than scraping it, would touch it. Fresh petrol, WD40, thinners, nothing. It also has an acrid smell, not petrol like at all.

I've played with engines for most of my life and I've never witnessed anything as bad as this. For example, I have a 1950's Lister stationary engine and its fuel tank has lain undisturbed for 15 years or more and still smells of petrol.

My question to the learned forum is "can anything be done with the inside of the tank" Access, of course, is near impossible to the whole of the inside. Should I simply ignore it and leave it bathed in fresh?

Appreciate any similar experiences and advice?

 

[sarabande]

is the tank meal or eek plastic/grp ?

 

[Fire99]

Not quite a boaty subject...........please indulge me

My road bike has been off the road for 3 years. It's only a summer use toy and I've had 3 good sailing seasons (there, now it's boaty!). Or should I say "my outboard motor has been unused for 3 years"

The petrol in the tank has degraded and separated and it's left an almost tar like residue. The tap was completely blocked and nothing, other than scraping it, would touch it. Fresh petrol, WD40, thinners, nothing. It also has an acrid smell, not petrol like at all.

I've played with engines for most of my life and I've never witnessed anything as bad as this. For example, I have a 1950's Lister stationary engine and its fuel tank has lain undisturbed for 15 years or more and still smells of petrol.

My question to the learned forum is "can anything be done with the inside of the tank" Access, of course, is near impossible to the whole of the inside. Should I simply ignore it and leave it bathed in fresh?

Appreciate any similar experiences and advice?

Rule of thumb i've been told is to either drain the tank or leave the tank full to the brim, so there is no space for air and condensation.

Personally i'd disconnect the tank from the carbs and flush it through with paraffin.

 

[TNT]

tar

Its actually a wax compound that is left when petrol evaps, heat is a good way to remove it as it turns more fluidic when hot, if you can wangle it with SWIMBO a good hot dishwasher with the tank upsideshould remove just about all of it, failing that a diesel powered hot steam cleaner will also get it out. Never heard or seem anything that will break it down back to fluid but there may be something out there, maybe a acetone or similar??...........not sure but may be worth a try.

PS, just had to sell my ZXRB4, she said it was a bike or a boat and I could not have both.!!

 

[Fire99]

Whatever you do, I wouldn't leave it. If it gets into the carbs then you're into blocked jets etc and things start getting very messy.

Having owned more bikes than I care to count, it's a real possibility if you leave them unattended for some time.

 

[Courageous]

Seafoam (and no I don't have any connection with the manufacturer). It's now available thru ebay uk and is considerably more costly than the 7 USD wallmart charge but at this time it's our only way of getting it.

My VF1000R had sat unused for 24 years before I got it. Only 69 miles on the clock but wouldn't run. We stripped the carbs to clean, better but not quite there. Seafoamed it and voila! It's very very effective.

 

[little shack]

I've had a similar problem a few years back,old gsxr 750 stud several years I believe it's called varnish so i was told . I tried to clean over an extended period been too tight to pay for it doing but as yousay nothing would shift it the worst part is when i parked it up i didn't believe it would befor that lengh of time and didn't drain the carbes result £40 prof clean i don't no what he used either

 

[DownWest]

Just looked at a Solex moped. The plastic tank had a generous coating of toffee at the bottom. Not been used for 12+yrs. Fuel lines blocked,, only way to clean was with thin wire. I presume this was from the oil used in the 2T mix. Petrol had no effect, perhaps if left for a while (yrs) it might. Bearing in mind the fragility of old plastic, I was V. carefull.
I now need to worry about the K75, unused for 5yrs, in the garage.
A