122 tooth gear rings have a "v" shape, whereas 149 tooth gear rings have a "u" shape. Be aware that just because your aircraft (or engine) is supposed to have a certain ring gear doesn't necessarily mean that it does. You should always confirm and order the correct starter to match. 

The D A M high temperature anti-seize formula is based on inert high temperature dry lubricants suspended in a naptha carrier with a few other low viscosity additives. The thick grease base in other anti-seize products on the market burn and char at exhaust temperatures leaving sticky hard deposits that actually contribute to the lock-up of exhaust joints. The D A M product carrier evaporates leaving only a film of dry lubricants in the joints that penetrates the pores of the stainless steel. 

High quality spray can paint has worked well when the prop has been cleaned and the metal primed effectively.

The McFarlane primer is available as a complete fuel primer assembly and knob assembly only, and replacement seals for the knob assembly are available. In many cases, where the old primer bore is still good, the McFarlane knob assembly can be used for a FAA-PMA approved quick fix for your existing primer.

Do you have aftermarket Monarch fuel tanks installed? We have received customer feedback stating that when Monarch or other aftermarket fuel tanks are installed, McFarlane’s fuel vent line does not fit. There is nothing we can do to solve that issue. McFarlane’s fuel vent lines fit well when OEM fuel tanks are installed. Please review the Installation Tips for McFarlane Fuel Vent Lines.

It's just a matter of removing the doors, pressing out the steel bushings and then pressing in the replacement parts. The kits include all necessary hardware including new bolts and spacers. Where the OEM sleeve part is flanged, the space is made up with a thin washer. Installation videos are available to demonstrate kit installation. 

The special heat treated elastomer in PROP GUARD absorbs the impact energy from the particle strike. In other words, PROP GUARD gives a little and spreads the energy when something hits it.

The compatibility question covers two issues: mixing one grade of AeroShell oil with another; and the effects on the engine of changing from one AeroShell grade to the other. If you typically run on AeroShell multigrade, and you find yourself in a place where only AeroShell single grades are available, you can safely add the AeroShell single grade to your engine. They are completely compatible. 

If you run on an AeroShell single grade during the summer, but want to switch over to AeroShell Oil W 15W-50 Multigrade for the winter, you can safely replace the straight weight with the multigrade at your regular drain interval. The idea that you have to stick with the type of oil you started with comes from the days of unusual chemistry when the resulting oils were incompatible. 

All approved SAE J-1899 (former MIL-L-22851) and SAE J-1966 (former MIL-L-6082) AeroShell oils are compatible. For example, if you have a high-time engine run on ashless dispersant oils and need to replace a cylinder, you can switch to a mineral oil for 50 hours or so to break in the new cylinder. The only time Shell recommends against switching is in a high-time engine run exclusively on straight mineral oil. Here, a switch to ashless dispersant oil can loosen deposits left behind by the mineral oil.

A good rule of thumb for changing piston engine oil is to change it every four months. Of course for every rule, there are at least two exceptions.

Exception #1: If you're able to fly frequently with proper oil temperature, you should adjust the four-month rule accordingly.  Change out your oil after 50 hours if you've flown the hours in less than four months.  If your engine doesn’t have an oil filter, change it after 25 hours. Always remember: the four-month rule is the most critical.

Exception #2: In recent years, the annual flight hours of many private planes have decreased.

And where there’s an idle plane, there’s rust.  When an airplane engine sits too long (especially in humid climates or if there is excess moisture in the oil because the oil temperature is too low), rust will form on many of the parts such as cams, lifters and cylinders. Then, once the plane has been started, the iron oxide will run through the entire engine oil system. 

While some of the larger pieces will filter out, many of the smaller pieces will remain in the oil and can act as grit on critical wear surfaces. If you don't plan on flying your aircraft for four months or more, be sure to use a storage or preservative oil to protect your engine.

There is a certain size rock that will break through the PROP GUARD and damage the propeller. When this happens, the damage to the propeller will be much less than if PROP GUARD had not been there, as much of the rock’s energy is absorbed by failing the PROP GUARD.

The carbon vanes inside the pump are sticking in rotor slots. Oil or solvent has entered the pump either from a bad oil seal in the engine case at the pump mounting area, or from pressure washing the engine with an oil-based solvent (spraying directly on the pump). The oil or solvent will work its way up into the pump through the drive end, mixing with graphite dust and turning into a paste like material.

A Dry Air Pump is just that: DRY. As the carbon rotor and vanes wear, they produce graphite dust which lubricates moving internal parts of the pump. When oil or solvent mixes with this graphite dust, it keeps vanes from moving freely in their slots and they stick. At low engine RPM, the vanes are recessed in their slots and create no vacuum, but as engine RPM increases, centrifugal force slings the vanes out, allowing them to grab air and create vacuum. Once a pump has become contaminated, its life expectancy is extremely short. The cause of pump contamination should be determined and corrected and the pump should be replaced as soon as possible. 

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.

Strut seal leaks and flat struts can be caused by roll or twist of the main O-ring seal. It is very frustrating to carefully check all the parts and surfaces and put a new seal kit in the strut only to find it flat again after a relatively short time. We have seen this happen when a film of MIL-5606 hydraulic fluid dries out on the exposed chrome strut shaft. MIL-5606 by nature has a tendency to get sticky as it is exposed to air and dirt and then dry.

Very slight dried oil films are sometimes hard to detect and they can get past the plastic wiper seal. When this happens the sticky strut has a tendency to grab the O-ring and roll or twist it when the strut slides in or out causing the seal to distort. A very small O-ring twist or distortion will cause a leak. This phenomena is aggravated by the low pressure that the Cessna strut is designed for. Wipe the chrome strut down with Stoddard solvent (mineral spirits) periodically to soften and remove any dried oil film, dirt, dust and bugs.

Use of a deep throated hand squeezer will make installation using one hand easier. Always adjust the rivet squeezer for the right rivet height when the squeezer is closed all the way. This gives you maximum squeezer leverage and ease of use.

Only when needed which is when the voltage reads below 13.28V. It depends on the battery model (the larger amp hour batteries will need less topping off than say the scooter battery) but if not in use or left in a vehicle, make sure you check the voltage and charge at least once a year. Due to lithium batteries extremely low self-discharge rate, less than 50% of its charge is lost over a 6 month period, so you may not have to charge your battery before the season starts! If the battery is 13.28V or higher, then all is good. If it is less than this, you need to charge it before engine start to ensure a long battery life.

It appears that Superior reverse engineered the 60882-type ring gear support assembly (for 122-tooth ring gears) when they manufactured and PMA certified Superior Ring Gear Support Assembly PN SL77579-1 Rev.11 (for 149-tooth ring gears). Unfortunately, when pairing those ring gear support assemblies with 149-tooth ring gears, the ring gear rests further aft than Lycoming specification and therefore tends to crash the front face of NL-type starters by a mere couple thousandths of an inch. Other starter models tend to stand back sufficiently from the ring gear, so the mismatch is not as problematic. Since the NL “hugs the line” defined by Lycoming, the mismatched ring gear and support assembly causes an interference condition.

The fuel selector valve works in unscreened fuel. Contaminated fuel can cause selector valve seal damage. When fueling from possibly contaminated fuel sources McFarlane recommends the use of a fuel filter, such as Mr. Funnel or another filtering device, to reduce trash in the fuel system.

There are two types of cloth that work well to prevent scratching on plastics.

The first is the synthetic micro fiber cloth. This soft supple fine matrix cloth will do an excellent job of protecting the acrylic surfaces. The down side of this cloth is that it is expensive and the wax and polymers used in plastic cleaners do not wash out well. The microfiber cloth will have to be thrown away when the wax and dirt buildup prevents a streak free surface.

The other cloth that works well is soft cotton cloth, with the best construction being T-shirt material. The fluffed soft cotton fibers have layers that isolate dust and dirt well from the cloth surface and they can be used many times. The cost is low enough that you can just throw them away when they get contaminated.