Badzuk

Sounds to me like the mixture of diesel to air is wrong. Way too much diesel or not enough air. I now replace my burner nozzles every year because they wear our and start spraying more fuel as they wear. I would start by checking the fuel pressure, it should be set 120-150 psi for best atomization. After that open your airbands up until the smoke clears up. if you can't clean up the smoke then you have too much fuel. I have backed fuel pressure down to 100 psi, but don't recommend going any lower. You're better off swapping in a smaller nozzle.

I run a 18 hp Vanguard motor on that pump, runs it very well.

Please stay away from optima batteries. They used to be good 10 years ago, but they have changed their manufacturing and materials, and now they fail rapidly. A group of us are into off-roading and have heavily modified and even custom vehicles with winches and tend to be hard on batteries. Optimas used to be the standard, but now we have a pile of 'em sitting in the corner, and several of them have been swapped out under warranty. They just don't last much past 2 years. We have used red and yellow tops. Look into Odyssey Batteries, If your going to spend the $$ on a good one theses are about the best at the moment. Sears Platinum batteries are rebadged Odyssey.

Sounds like the spring you lost is part of the check valve built into the output of the unloader. It will not function properly without the check valve, it will cycle alot in bypass. The check valve keeps the pressure in the hose instead of letting it bleed back into the unloader.

I would remove it, it you leave it on you risk sucking air in through the damaged diaphragm and causing more problems than picking up a plug.

One more thing I have done with all my burners is wired in a manual ON switch that automatically bypasses the flow switch and thermostat (if equipped). That way it is easier to test for a problem with the burner without having to run the machine and have water hooked up.

I've gone both ways with this, I've just started using a temperature controller again on some of my machines, more as a high limit cut off than being able to adjust the temperature. I've adjusted my burners by using the proper sized nozzle to limit the max water temperature to about 170-180 at full water flow/burner constantly on. That way when the flow switch gets stuck (always in the on position) as long as they keep spraying they can finish the job. Not ideal, but it has worked in a pinch. My latest project uses a digital PID temperature control unit. So far this has worked really well, but I've only had it in the field for about 6 months. It even has an adjustable alarm output, so you can hook up a horn strobe to it to notify of an overheat scenario before steam hits the gun. The controller has a digital temperature readout that shows current water temp as well as the target water temp. It can switch both solenoid relays and solid state relays, but I was not able to make the SSR's work properly, I had too much voltage drop across them. (possibly due to inferior relays, I bought inexpensive to testy my theory)

Not sure of your exact setup, your a little vague on the details, but it sounds to me like your CAD eye is bad. When the cad eye doesn't sense a flame it will trip the reset and shut down your burner. $10 part, or it may just be covered in soot and need to be cleaned.

From my understanding this is not entirely correct. Most pressure regulated unloaders are designed to work with about a 5% bypass to help cushion the unloader and keep everything working within spec. If you have it set to not bypass any water under use then the unloader becomes incredibly inaccurate at regulating working pressure. It sounds to me like you have a problem in a couple of areas. First if you have a 4000psi pump don't let your pressure spike above that, it is hard on equipment and unsafe. Second if you are running the proper size tip for your machine and can only see 2900 psi working pressure then either your unloader is set improperly or in need of rebuilding or your pump is due for a rebuild. With the wide pressure variations you describe ind your post I would start with the unloader. (again assuming no leaks in in the hoses and no air leaks in the supply AND proper sized nozzels in good condition) If you are not comfortable trouble shooting your machine please take it to a reputable shop, 4000psi is dangerous, and I would hate for someone to get hurt due to ignorance.

I just use 30wt non detergent oil and change it a couple times a year. Haven't had any problems yet. I do have one of my old pumps that needs bearings replaced, but that was due to it being run with water in the oil and a general lack of maintenance. (This was the same guy that called me out to repair his machine that wouldn't start and run worth a crap. Turns out it was out of oil and the low level switch kept it from starting. I was not impressed.) Now I check my machines myself on a regular schedule instead of relying on my help to do it. I haven't had any issues with pumps getting warm. They can run all night and you can lay your hand on them.

Viton o-rings are 7x more expensive, but I'm considering buying some to see if they hold up any better behind the turbo tips. It seems that the vibration from the turbo tips is rapidly eating o-rings, but I really don't think Viton would hold up better, but I'm probably going to give them a try. I found that I have much fewer pump and unloader problems when I keep a good supply of o-rings in each truck. It is amazing how much extra wear and tear a leaky o-ring puts on a machine...

I just buy bulk Buna-n o-rings from Grainger. 100 pcs for about $3. Part # 1KEZ9 for 3/8" and 1KEZ7 for 1/4"

Thanks for the help. Has anyone completely rewired their machine? Some of the previous fixes on these machines have really left a lot to be desired. I would like to make a new control box with a few indicator lights (main power, flow switch on, thermostat on, burner on) and some fuses to protect everything. Maybe even include a test switch to bypass the controls to test the burner. I'm thinking a terminal strip to make it simpler to replace the flow switch and thermostat. Currently I have an on/off switch and a flow switch, no lights, fuses, or thermostat. There is a relay in the circuit. Or does someone make a control box similar to this that I can install? Thanks again...

Thanks for the replies, I appreciate the help. The burner is after the unloader, so the bypass water is not moving through the coil at all. Once the flow is stopped the water in the coil doesn't flow. I have 5 machines that I run, 3 are Alkota, one is an old north star, and one is an electric drive unit. All my machines run the General pump (4GPM 3500psi), and all but the electric unit use a 13 hp Honda motor. All units have diesel fired burners, and the north star is the only one that is vertical. I've only been managing the hood cleaning division for the past year, and our "mechanic" does some interesting work when repairs are needed, so I've recently took over most of the repair work so that it can be fixed right and not cobbled together. I need to bring these machines back up to par, I can't have one of my guys getting hurt because we removed a safety valve or something stupid like that. What is the correct plumbing for these machines? What safety measures/items need to be in place? It looks like most of the safety valves have been removed as they failed (scary). Currently water flows as follows Pump, Unloader, Flow Switch, Burner, then out to the hose and gun. I would like to install a thermostat and high pressure relief valve, but what else should I be looking at.

Thanks in advance for any Help you can give... One of my machines has a vertical burner on it. The issue I have is that once the water flow is stopped (and the burner is shut down) the temperature of the water in the coil continues to rise. The burner does a good job of raising the water temp about 90-100 degrees, and maintains that as long as the water flows. Once you release the trigger, the pump goes into bypass and the burner shuts down, but the temp continues to climb. When I tested it yesterday I had a temp reading of 230 within 5 minutes of the pump in bypass. It seems that the water continues to absorb the heat from the coils and burner. Any Help or ideas?