Unleaded petrol

[MarkPhillips]

Hi everybody I ride a 1959 Red Hunter that by and large runs and starts very nicely for about 400 miles and then I start to get petrol starvation problems, first she ticks over erratically then starting takes 3 or 4 kicks to start then power starts to fade.
I fitted a brand new Amal carb and fuel tap this winter which both have micro fine filters and what’s happened twice now this year is they and the pilot jet get very slightly gummed up with petrol residue. It only takes a squirt of carb cleaner and it’s fine again but annoying.
I have been running E5 petrol and only filling the tank half full to make sure I use it up regularly trying to avoid stale fuel also a little drop of red ex.
I’ve cleaned the tank out twice with fresh petrol all nice and clean.
I’m assuming that it’s rubbish unleaded causing the problem, I have tried different stations, unfortunately both supermarket nothing else round here.
A bloke I know down the Tuesday night bike night swears by a drop of modern synthetic two stroke oil per tank in is BSA.
my question is does anyone have any recommendations for petrol additives.
Cheers Mark

[simon.holyfield]

What about trying the Aspen fuel they sell for lawn mowers? Changing the fuel should help you prove where the problem is coming from.

[JohnA]

I've put 50:1 two stroke mix in my TR7V several times when I haven't had any neat petrol. It is E10, used for chainsaws. The bike runs very well on it - noticeably better than when I've tried neat E10. Normally I use E5 and it is fine with that. I try to use branded petrol but don't always have the choice and I must admit, I've noticed no difference using supermarket petrol. Another possible point in favour of adding a drop of 2 stroke oil may be that it tends to minimise the formation of residue. I've discovered chainsaws that I've left with half a tank and haven't used for over a year, and expected them to need the carbs cleaning before they'd run. But they've started and run perfectly, so my assumption is that the 2 stroke oil might be why.

[RalphM]

Try Esso Supreme if you can get hold of it.

[Roger Gwynn]

I suspect that your tank has been lined with a resin coating to seal it some time ago when the coatings were not compatible with ethanol. The lining slowly dissolves and in my case gummed up the slide causing the throttle to stick open. Check inside the tank to see if there is a coating that is slightly sticky to the touch. The only recourse is to remove the old coating and replace with a new one or another tank. Draganfly can supply all the chemicals you need. Ariels are not really susceptible to problems with old fuel, I used fuel from my Ducati that wouldn't run at all, the Ariel said meh!

[MarkPhillips]

Hi thank you very much for your replies.
Yes I suspected the tank had been resin lined given its age but when I got the bike I put a hand full of 8mm nuts and 1/2 a pint of petrol and gave it a good old rattle then emptied it into a white bucket just a little rust that’s all. Had a Check for anything sticky but no. I will investigate further this winter.
I’ve come round to the idea of racing two stoke oil it’s not just lubricant but cleaner moister repellent it’s all that keeps a race bike going under extreme conditions.
I’m also looking at a lead substitute called valve master an additive for classic vehicles claims to stabilise ethanol amongst other things. This bike is just one big learning curve and lots of fun.
Cheers Mark

[RalphM]

If by racing 2t oil you mean Castrol R then you have possibly found your problem, it's fine in a race engine that is striped regularly and run on race fuel but makes a right mess of a road engine, I have seen a few were they added a little to the fuel for the smell and it wasn't a pretty sight.

[Mick D]

Hi

It might be worth fitting an additional in line filter, just for a while to see if it's actually 'dust' blocking your jet.

Regards Mick

[nevhunter]

Castor oil won't mix with Petrol without the aid of special mixants. It also oxidises and goes gummy. ANY modern 2 stroke oil will dissolve well and maybe do some good at cleaning the Combustion chamber. It will do more good in earlier Open Valve Motors where the Valve guide Lubrication is Marginal. Contrary to some beliefs Tetra ethyl Lead only Helps Exhaust valve seats to seal better as the very high temps there make it act as a flux which stops oxidation and lubricates. Nev

[markus.nikot]

In some of my Ariels, various old tank coatings have dissolved. They’re either rubbery or hard chunks, depending on the coating. The only solution, as Roger wrote, is to remove them and apply a modern, ethanol-resistant coating.
By the way, I run all my Ariels on E10 without any problems.