back firing through tailpipe

had a small rough idle on my 50 added mmo 5 oz to 10 gallons of gas 2 times now I cant hardly feel it idle now the old girl gets a treat every other tank this is a great product
 
I'll try a good dose of mmo. Couldn't get time to rebuild a carb yet, but that's next. Tough thing to chase down!
 
my 50 developed a somewhat rough idle no problem with ignition so I started using mmo in the gas after 2 tanks of gas I could hardly feel it idle and even seamed to have better performance since then the old girl gets 10 oz of mmo every other tank its a very good product that's been around a very long time
 
I use ATF in the fuel as it is more cost effective ( I am Cheap). I get it for a dollar and a half at the Dollar store.
 
GB SISSON said:
I'll try a good dose of mmo. Couldn't get time to rebuild a carb yet, but that's next. Tough thing to chase down!
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GB in your situation on exhaust pop on deceleration.

It might just be unspent gas in the exhaust igniting.

Hard to say, don't know. But just a guess of a rich setting. Maybe ignition. But it'd run real bad always.


Just a simple rule of thumb for me is pop out carb, lean (stuck/burnt intake valve)... pop out exhaust... rich mix (maybe a stuck ex valve, plugs?).



Granted timing, if not ruled out! So simple it's complex sometimes.



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slowforty said:
I use ATF in the fuel as it is more cost effective ( I am Cheap). I get it for a dollar and a half at the Dollar store.
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ATF will eat paint quickly. Not sure I'd want to run it through an running engine (carb and gaskets). But I don't know. MMO is not that expensive, you probably could just use some diesel fuel with a bit of 5w-30 mixed in too if you have it sitting in the shop.



I've never had to do it more then once in the spring, and a little in the gas. I don't ever run a lead additive.







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2 cycle oil as an additive can do the same thing. It is meant to burn, unlike motor oil. I feel my problem is raw gas in the exhaust igniting. It runs and idles quite nicely. Problem is with the dead of winter upon us and these very short days up north I have been spending any spare time wiring up a headlight/tail light circuit for this truck instead. Circuit breakers, relays, four cast-off extension cords and a fistfull of connectors surrounded by 8' of heat shrink tubing. Gonna be a bullet-proof set of halogen headlights in an old farm truck. 75 square miles of island back roads and no street lights. It's dark out there.
 
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