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MG MG Y Type - Fuel

On my first run of the year and on the way to get petrol my YB stopped . I cleaned the fuel line filters and the carb bowl and got going again only to stop within a short distance . This behaviour continued but I eventually got back home having covered less than a mile in about 3 hours .
I now assumed that the fuel pump to be at fault and had to be replaced .
Some time later I thought I would add some fresh petrol . The car initially run very rough but soon cleared to run as sweet as normal .
So my problem was bad petrol .

I wonder if the metal pellet catalyst would have prevented this breakdown of the petrol ?
E Winters

Might not be bad fuel.With modern fuel most Y types need a heat shield between the carb and manifold and possible insulation or rerouting of the fuel pipe from in front of the battery box.
Paul
P M Grafham

Today's fuel has a manufacturers shelf life of around 6 WEEKS. It will still run after 6 weeks, but not as well. Marine shops sell a fuel stabilizer if you are planning storage beyond a couple of months.

Modern fuel has a vapouring/boiling point of 70 degrees (it is designed for closed system injected cars), so in our cars the volatiles are quickly lost through the fuel tank and float bowl vents.

The fuel is what it is - you just have to be aware of the issues using it in older cars and manage the problems.

Cheers

Tony
A L SLATTERY

So what about the metal pellets which are advertised as catalyst helping to prevent fuel problems
E Winters

My understanding is the pellets are alleged to reduce valve seat erosion - they have no effect on fuel volatility or shelf life.

You may have also had a sticking dashpot piston. It can take some time for the piston to move smoothly after sitting for some weeks - all depends on the oil you use in the dashpot & local climate.

You may also have had some dried fuel residue on the valves in the pump - so not delivering enough supply until cleaned away by the volatiles in the fresh fuel.

Cheers

Tony
A L SLATTERY

Lifted from MGCC Y Register's Facebook Page, their words and views copied and paste below, not my views but thought you may find it helpful.........

Snake Oil Salesmen. Copy of my letter to a magazine;-
Dear Editor,

I'm very sad to see that you have been taken in by an advert that has been around since the 1980s, perporting to be all things to all engines. On the inside back-cover of the January 2018 issue of 'Legion' we are told of the benefits of a very dubious product. This 'tin-balls' idea arose in the 1980s and was advertised in many car-motorcycle related magazines. So impressed was the 'Practical Classic' magazine in the 80s (still being sold) that they obtained an old Austin 1800 and put the product into its petrol tank. It was a disaster (valve seats burnt out in less than 300 miles). Back then the 'tin-balls' were supposed to protect the exhaust valve seats of old cast-iron engines when unleaded petrol arrived. It did not. (They claimed back then that the tin had protected the exhaust valve seats of the RR Merlin engines fitted to Spitfires sent to Russia in WW2. Alas, the RR Merlin engine is made of magnesium alloy with screwed in hardened steel valve seats that were designed to cope with incandescent gasses. They claimed the tin also raised the octane rating of the poor Russian fuel.) The product was sold as little metal balls in a plastic net bag to be dropped in the petrol tank. Later, once many car magazines had barred their adverts, it re-appeared as 'Black Cat', an in-line petrol fuel filter that acted by catalytic methods to imroved fuel economy and engine performance. When Ethanol was added to petrol they then claimed the tin would protect fuel systems from the effects of this powerful corrosive stuff, which ate the tin out of the solder that held float-chamber floats together. It did not. It has now re-appeared as 'TFC', metal pellets made from " rare earth metals" (tin, lead and zinc) as you see in the advert in the Legion magazine. Because few car-motorcycle-etc magazines will take their adverts, they are now targetting less technical outlets.

If tin balls (or pellets) are so good, why do not the manufacturers of their engines not add them to their petrol tanks? Why go to the expense of machining cylinder heads and fitting hardened steel inserts in the exhausts if a tin ball will protect them for pence? Note I say pence. You can put similar 'tin balls' in your tank for about 50p, just cut up some solder from the garage. And why one needs to buy different amounts for engine sizes is amazing, as they say themselves the balls/pellets last forever. It is the fuel they claim to treat so it matters not if one gallon of 50 gallons pass over the tin balls, totally irrelevant to engine size.

Its an out and out con-trick. Save your money. I attended a Classic Car Spares Event at Stoneliegh some years ago, and a chap was selling these tin balls, claiming to prevent valve-seat-recession (unleaded fuel burning away the exhaust valve seat). He quoted the Russian story (the latest add says 'Hurricanes, not 'Spitfires' as they found out no Spitfires were sent to Russia) and I stood up and told him about the RR Merlin engine being of Magnesium alloy and the valve seats being of hardened steel. He had no reply and his audience drifted away. It seems the manufactrers of this Snake Oil franchise its sales out, so protecting themselves from the ASA.

If the product does work, I sincerely hope those using it have told their insurance companies of the 10% rise in their engines power output. This brings to the front just how these 'improvements' were measured, and by whom (specialist engineers or an amature?) The photos are of solder used for joining metal at low temperatures, and how to cut off a few bits to put in your tank for about 25-50p. Their profit margin must be fantastic.
R E Knight

The earlier post from December 2017 and then the above copied from post in January 2018...
Again lifted from MG Car Club's Y Register Facebook page... hope no Oil Salesmen are offended by their comments... Sure knowing the Y Register if they were called this particular comment they would be first to moan... or block comments LOL.

Richard

R E Knight

My view is that the old theory of storing your car over winter with a full tank to eliminate air from getting at the fuel etc is now a dud as the fuel goes off so quickly
Better off storing as empty as possible and refilling with fresh when driving time comes around-
2 months pulls my mate's hotty MGB up, any longer than that and it's on a rope to get it fired up to get to the bouser
Funnily some cars are more prone to it than others--a bit weird really
William Revit

You can download a DXF file for making/have a heat shield made by a machine shop from the Parts Drawing page now Ed.

Also consider adding an insulation block from a BMC Mini carburettor and getting longer bolts (be careful to match the thread of the existing bolts though!

Paul
Paul Barrow

Not actually Y type, but a Honda GX 200 on a generator that I am repairing for someone.
It has been standing for a few months unused and wouldn't start when needed. The photo shows the float chamber, gummed up solid with a Tar like substance difficult to remove. Carb scrapped. More significant was the inlet valve was also gummed partly open, and when attempting to start, the pushrod was bent, also now scrap!

The Honda manual recommends a fuel stabiliser be added to the fuel tank of any engine that is used infrequently (like this one) or be drained completely

Regards
David


D P Jones

I drained 2 gallons of fuel from a tank in to a bowl. Didn't have a funnel handy to transfer to a can so left it until next day - 24 hours later.
The fuel had gone from totally clear to completely cloudy (like a cloudy Cider). This was due to the Ethanol absorbing moisture from the air due to the large surface area. Hence, leaving half a tank of fuel for a period can absorb moisture. Combined with a long standing period, the fuel degrades quickly. This will cause gum in the tank and lines but also promote rusting.
P Downing

Before I store my Y for winter (4 to 6 months), I always syphon the tank as much as I can and add lots of fuel stabiliser to the tank in order to minimize gummy degradation of the remaining fuel.

Here in Canada, the only gasoline that doesn't incorporate the devil's Ethanol is Shell Super. It degrades slower and doesn't have bad side effects on rubber components associated with Ethanol. I'm sure that you have more gasoline companies (other than Shell) who offer good old time PURE gasoline in the USA.

I also have a heat shield, but avoiding vapor lock remains a bit touchy in early spring when gas stations still have some «winter mix» gasoline (more volatile) left over and the temperature gets very warm.
Gilles Bachand

This thread was discussed between 02/07/2018 and 10/07/2018

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