Carbon fouling is indicated by dry, fluffy, sooty deposits. The plug is operating too cold to burn off combustion deposits. This may be fuel related or ignition related. Fuel related causes include rich fuel mixture, faulty carburetor adjustment, excessive idling or improper idle mixture. Ignition causes could be related to a worn spark plug ignition lead, improper magneto timing or running too cold of a spark plug.

Oil analyses can help you discover engine problems before they turn into major failures. But the analysis information gained is only as good as the sampling procedure. Also, a single test is not enough to reveal trends and significant changes and can only tell you if there is already a serious problem like a scuffed piston. Take oil samples properly. For best results, take the sample about midway through the draining of hot oil from your sump. 

A sample pulled off at the beginning or end of the oil change may appear dirtier than it really is. Sample the oil the same way every time. An improperly taken sample can lead to some seriously inaccurate conclusions about engine malfunctions. Rely on a series of consistent tests over time. You’re looking for significant changes or trends over time, not absolute values.

People want to label the results of a single test as good or bad, but the system doesn’t usually work that way. Say you’re buying a used aircraft. Don’t rely on just one very good result of just one report – it could have come from a 5- or 10-hour sample. Relatively constant numbers from the last six oil changes are a far better indicator that the engine is in good condition. Your record of regular oil changes and analyses is also helpful when selling an aircraft. 

Be consistent. If you change your oil at 50 hours, and then at 25 hours the next time, the first sample may show twice the wear metals. (Expect higher wear metals during break-in or following some maintenance procedures such as a cylinder replacement.) Finally, always remember that oil analysis should be part of a good maintenance programme, not a replacement for one.

There are no bill backs on a core return that is a current series 4300 or 6300 Slick Magneto. 

Typically Tempest spark plug resistors will stay between 1000 and 1500 Ohms throughout their life. Tempest specifies that the plug resistor should never be below 500 Ohms or above 5000 Ohms. We offer a lifetime guarantee on our fired-in resistor.

If a battery does not seem to charge or perform as well as it once did, it may be for one or more of the following issues:

• There may be a problem with the charging system. While the charging system is in operation, it will begin putting out approximately 13.8 -14.6 volts.
• The vehicle electrical system may have a short circuit or current drain
• The terminals on the battery are not properly tightened
• There may be a problem with the battery itself so if you have verified that it is not a parasitic drain, and the battery is losing power within 1-7 days, then contact EarthX. Do not continue to attempt to charge or use a battery that will not hold a charge as it might indicated cell failure and continued use can cause cell rupture, smoke and even fire.

Both short and tall filters are approved for most engine applications. Determining which height filter to use all depends on the space you have inside the engine cowling. We suggest going with the taller of the approved oil filters if you have the space.

Note: Tempest’s replacement recommendation is the same for both short and tall filters.

Yes, using a cooling shroud whether on a 200 series or 400 series dry air pump can reduce pump temperatures by as much as 10%. For more information, go to Vacuum Pump Cooling Kit.

Yes, you should rotate your spark plugs every 100 hours. This will help even out electrode wear caused by constant polarity and capacitance after-fire. Place them in a Tempest spark plug tray (P/N T240) and follow the rotation guide supplied on every Tempest spark plug box.

Yes, low oil temperature can lead to excessive rusting and corrosion of critical engine parts. When an aircraft sits on the ramp or in a hangar, the engine heats up during the day and cools again at night. While the engine is cooling, some of the moisture in the air condenses on the engine walls and drops into the oil. 

This can form rust on internal engine components. The moisture can also react with by-products of combustion in the oil,forming acids which can lead to corrosion. The best way to remove this water is for the engine to boil it off during flight. Studies have shown that the temperature of your engine oil increases about 50°F as it circulates through the engine.

Therefore, unless the oil temperature reaches 170°F to 180°F during flight, the engine will not boil off the water that has accumulated in the crankcase. The result: rust and corrosion.

Note that an excessively high oil temperature will also cause problems. Here are some tips to help avoid oil temperature problems:

Check your oil temperature gauge for accuracy. It should read about 212°F when the sensor is placed in boiling water.

Monitor the oil temperature during flight. It should be about 180°F even in winter. If it is lower, you may need a winterization kit. Otherwise, check with your mechanic to see what is causing the excessively low oil temperature.

The unique additive feature in anticorrosion/antiwear AeroShell® Oil W 15W-50 can also help control problems caused by rust and corrosion.

The ETX-Series of batteries have over discharge protection and is designed to prevent a continuous active drain on the battery to the point of damaging the battery, such as leaving your key in the on position, master switch on your aircraft, or parasitic draw as examples.  If your battery is reading 0V, or near 0V, then this protection might be activated.

To determine the actual voltage of the battery, remove the negative battery cable and measure the voltage at the terminals with a voltmeter.  If less than 8V, it will not accept a charge.  Once a lithium battery is approximately 8V, it can be permanently damaged and the EarthX BMS is designed to not allow the recharging of the battery as this is no longer safe to do and can be dangerous and cause cell rupture.  Never force a charge into the battery. This is not a battery defect, nor a failed battery, but instead the protection working as it is designed.

The rate of discharge depends on how many amp hours the battery has (less Ah = faster discharge) and the ambient temperature (warmer = faster discharge).  When the EarthX battery is about 95% drained, the BMS over discharge protection will disconnect the battery from the active drain so that you do not continue to discharge the battery to the point of damaging it. You know this has happened when you put a voltmeter on the battery installed in the vehicle and it reads close to 0V. We allow this much discharge of the battery to provide you the most energy possible if the drain is intentional, ie: your alternator fails in flight, and you are powering your electronics with the battery. The battery will continue to drain, at a much slower rate, with time as this is impossible to stop batteries from self-discharging.  Even “brand new” batteries left in a box will drain and if not recharged and maintained, will be permanently damaged.

It is very important to recharge the battery immediately if it has been drained.  The longer the battery remains discharged will shorten the overall life span and increases the chance of permanent damage.

Depending on the amp hour of the battery and the environmental temperature will dictate how much time can pass before it is permanently damaged.  Example, the ETX12A is a 4Ah battery and should be recharged within a week whereas the ETX900 is a 15.6Ah battery and should be recharged within a month of finding it in this state.

Most of the time, it means you need to charge the battery as it is at a low charge level but it could mean several things. First thing you need to do it put a voltmeter on the battery, if the voltage is less than 13.28V, the LED light will flash to let you know to charge the battery. If the voltage is above 13.28V and flashing, then you could have a weak cell /a cell out of balance/or defective cell and you need to contact EarthX for a warranty coverage if it is less than 2 years old. The LED will also flash if the voltage is too high, above 14.6V. If the light is solid and remains on for more than 10 minutes, then it is an indication of a BMS electronics problem and contact EarthX.

Diaphragm fuel pumps should be replaced or overhauled:

1. At engine TBO or after ten years in service, whichever occurs first. Replace on condition if leaks develop or performance drops for example.
2. Refer to Lycoming Mandatory Service Bulletin 240W for information regarding engine TBO.

No. As with any battery being charged it is best not to do this in the event of a faulty charger. Follow these safety tip for charging ANY type of battery.

• Never leave the battery or the vehicle unattended when recharging it.
• When charging a battery, place it on a non-flammable, and remove any flammable items nearby.
• Unplug chargers from the battery or vehicle always after the battery reaches full charge.
• Disconnect chargers when not in use.

We can only speak for Tempest overhauled pumps as we have no control over the quality of other overhaul shops. Before Tempest®/Aero Accessories, LLC offered an overhauled pump, they spent more than a year in research and testing to determine what was required to produce a quality overhauled pump that would last as long as a new pump producing the vacuum or pressure required for aircraft application. In 1984 Tempest®/Aero Accessories, LLC had its overhaul process specification approved by the FAA and began offering quality overhauled vacuum pumps to general aviation. Tempest takes great pride in their state of the art overhaul facility, and produce the best overhauled pump on the market today. Over the years they have acquired FAA-PMA’s for all component parts of the Dry Air Pumps, and have supplied replacement parts to all overhaulers worldwide.

D A M window cleaner is a mixture of non-toxic wax, polymers, and a mild detergent with the slightest trace of alcohol. It is an irritant to the eyes if it has direct contact.  

No. Most of the metallurgy in the valve train of aircraft engines was designed to be operated on leaded fuels. Even 80/87 engines were designed for fuels with 0.5 gram per gallon lead.  Experience has shown that the lead level in aviation gasoline is especially critical during break-in. So, if you’re breaking in a new or an overhauled engine, make sure you use a leaded 80/87 or 100/130 low lead aviation gasoline for at least the first 50 hours of operation. Some fuel suppliers sell an unleaded 80/87, so make sure you're getting leaded gasoline for breaking in your engine.

The old adage that one should never change oil types was based on problems with some oils with very “unusual” technology that were in the marketplace over 50 years ago. Present oils are compatible. So many pilots use AeroShell Oil W 15W-50 multigrade in the winter months and then switch to AeroShell Oil W 100 or AeroShell Oil W 100 PLUS single grade in the summer months. You may see small changes in oil temperature or oil consumption with this change, but it will not hurt your engine.

Yes, this is normal. A lithium battery can and will accept a much higher charging current than an equal size lead acid battery. If your battery is not fully charged, your alternator can potentially output a current equal to or slightly above the alternator’s rating for a few minutes to top the battery off. Your fuse, breaker, or current limiting device should be sized approximately 20% above the alternator rating. Example, if you have a 40 amp alternator, use a fuse, breaker, current limiter set to 48 amps (or 50 amps).

A common cause for this problem is fuel starvation due to improper installation of the fuel pump. Make sure that the fuel lines are not crossed; that is, the inlet line should be connected to the inlet side of the pump (marked “IN” on the top of the port) and the outlet line should be attached to the fuel pump outlet port. Fuel should be present at the inlet side of the fuel pump.

Improper installation of the fuel pump may result in a misalignment of the operating lever with the operating plunger in the accessory case. If so, there will be no movement of the lever and no pumping motion to provide fuel flow. If misalignment is found upon removal of the pump, the lever is probably damaged or broken. If misalignment of the operating lever has occurred, it will require inspection and repair by a qualified technician.

1. Check your hoses to make certain that they are not collapsed or kinked.
2. Replace the system filter(s). A dirty or clogged filter will cause the pump to work significantly harder than normal and could cause premature failure.
3. Make sure that you have the correct pump installed on your aircraft.
4. Make sure that no oil contamination is entering the pump.