Dk50 HSt Blowing blue smoke

coobie · Jul 15, 2014

liberty2701 said:
Dealer called and said fuel looked ok. They said smoke cleared up some. They are waiting on an additive from Kioti to put in the fuel. Fuel already has Pri d and Howes in it so not sure if this is going to help. We shall see.

Good luck to you.Hope it all works out well.

sdef · Jul 15, 2014

liberty2701 said:
Dealer called and said fuel looked ok. They said smoke cleared up some. They are waiting on an additive from Kioti to put in the fuel. Fuel already has Pri d and Howes in it so not sure if this is going to help. We shall see.

So if the fuel looked okay- I assume they tested it, I have to wonder what kind of additive they would be trying? Personally, I have little faith in additives (snake oil in most cases), above what the refineries or distributors put in there, other than a known fuel stabilizer like what you already have and something like Opti-lube.

liberty2701 · Jul 15, 2014

This is what they told me. I asked about actually testing it and he said no we just inspected it visually. He said it looks good.

MinnesotaEric · Jul 15, 2014

ritcheyvs said:
As a point of information, defective valve guides and valve guide seals rarely produce serious smoke in Diesel engines. Without a throttle to restrict air flow during the intake stroke, Diesels create very little vacuum in the cylinder so they can't to suck much oil down the valve stem. Gasoline engines, on the other hand, typically idle with 30 inches of vacuum in the intake manifold and that can suck any available oil down the valve stem and into the cylinder.

Valve guides can cause smoke too in low vacuum application if they are screwed up enough, but you're point id valid and i should have better explained my meaning. It occurs to me that I'm all automotive and we have emissions systems that should prevent raw, atomized fuel from coming out the tailpipe, which does color my experience.

FWIW, a gasser engine that isn't forced induction at 2000 ft above sea level should pull between 17" to 21" of vacuum (more vacuum the more cylinders are added because of the smooth flow of air velocity). For every additional 1,000 feet above sea level, you'll drop around 1" of vacuum. You might be able to pull up to 5" more of vacuum of you briefly rev the engine.

ritcheyvs · Jul 15, 2014

sdef said:
So that explains why performance diesels (tractor pulls, etc.) have black smoke pouring out of the stacks. I would have thought too rich of a mixture would have cost some power.

Gasoline engines run very close to stochiometric so the fuel-air mixture is nearly ideal for ignition. This means that the amount of air AND the amount to fuel must be regulated in a synchronized way. Diesels, on the other hand normally run very lean; the air is not restricted or limited at all but the amount of injected fuel is controlled.

If you inject excess fuel (not enough air to fully burn the fuel), the engine will make more power up to the point where the heat produced by burning the excess fuel is lass than the heat required to vaporize it. At that point, the only way to get more power is to add more air, e.g. supercharge. Supercharged gasoline engines are normally less efficient than normally aspirated engines, after all, the supercharger makes no difference until after the throttle is wide open. Diesels (with no throttle) are always wide open and turbocharged Diesels are often more efficient than normally aspirated Diesels.

liberty2701 · Jul 18, 2014

The verdict is bad diesel. The mechanic could not believe it. He figured it was going to be a bad injector or something. The diesel looked exactly the same as the diesel they used. No water and clear. I am shocked considering how the diesel was stored and the additives that were used. The bright side is it gives me faith in the tractor. The bad side is that I cannot rely on stored diesel when I need it. I have never had a fuel related problem either gas or diesel. I always take the precautions needed to keep it fresh. I would like to send a sample of the bad diesel to a lab to get it tested for my own curiousity. I cannot use the test swaps since they are for un-dyed diesel. Any suugestions on a lab?

murphy1244 · Jul 18, 2014

Pour it thru a Mr. Funnel and see what you get.

liberty2701 · Jul 18, 2014

Fuel already went through a sediment/water filter.

sdef · Jul 18, 2014

murphy1244 said:
Pour it thru a Mr. Funnel and see what you get.

Agreed. I have all of their different sizes use these for all of my stored fuel when poured out.

I use Blackstone labs for all of my oils testing. I do not know if they also do fuels.

The bad diesel makes a lot of sense. One can't just look at fuel ans tell if its bad, except maybe if it is terrible.