Starter – how to lubricate and help it last longer
by Had Robinson
1. Reducing the engine stop forces on the Top 80 starter
Inherent in the design of the Top 80 starter is that the pawls will engage the starter reel when the engine speed is below a few hundred RPM. This would not matter except that that the
pawls and starter reel take a beating. When the engine slows down almost to zero RPM, it will not have enough momentum to make it through top dead center. Instead of continuing in the
same direction, the engine reverses itself and grabs the starter reel at the same time, putting a terrific yank on it. As the starter begins to turn backwards, it is stopped by the action of
the cord. This yank puts a tremendous amount of extra wear on the entire mechanism. How is this fixed?
While we cannot stop the reverse yank at all times, we can cut it in half, more or less, by pulling the starter out a foot or two and THEN stopping the engine. As the engine dies (and
reverses), release the starter. The result is no more violent yanks.
This is a small task but over the life of the engine (and starter) it will make a difference.
2. Starter lubrication for the Top 80 & others
Every 50 hours (or as needed) perform this maintenance on the starter. If you have a Polini starter, see the Flash starter
page. Be extremely careful working with starter springs. Wear nitrile gloves and eye protection.
- Remove the entire starter from the engine. You may to remove other parts, like the seat, or the muffler assembly (Thor models). The pulley(s) unclips from the frame.
- Remove the rewind spring tension. All starter pulleys have a notch in the pulley for unwinding the spring. Pull the starter cord out a few inches until the notch is even with
hole that cord exits. Hold the pulley from rewinding. Use a hook to lift the cord out and up so that it falls into the notch in the pulley. Put tension on the cord with your
fingers so it stays in the notch as you let the pulley SLOWLY rotate. The pulley can turn a full rotation or more without having to disconnect the cord from the pull handle.
- Remove the center screw and carefully pull out the starter pulley (starter reel). If you do it correctly and carefully, the spring will remain inside the pulley.
CAREFULLY NOTE WHICH DIRECTION THE SPRING IS INSIDE THE PULLEY! The best way to do this is to take a photo with your cell phone. The spring can be
wound in either direction. Get it reversed and the starter does not work too well....
- The starter cord will be connected to the pulley and also to the starter housing. If needed, the cord can replaced at this time or after you clean and reinstall the spring. In
any case, wrap the cord around the pulley and note how many turns it takes to rewind the cord. You will need to know this later on.
- Remove the spring from the pulley. It is removed by slowly pulling out the outermost part of the spring first while using your thumb to hold the rest of it. Let the spring
unwind one revolution at a time NEVER all at once. Once it is free of the pulley, the spring will be about 70 cm/2 ft in diameter.
- Use a towel soaked in mineral spirits to thoroughly clean the spring. Remove every trace of grease and oil.
- Install the spring by hooking the outer part of the sprung to the outer notch in the pulley. Using your thumb and fingers, push the spring into the pulley cavity as you turn the
pulley with your hand. It takes two hands to do this. A thumb needs to be firmly pushing on the spring where it goes in the notch. Continue pushing and working the spring
into the cavity until the entire spring is inside.
- Lubricate the spring with about (10) drops of light machine oil. DO NOT USE AUTOMOTIVE ENGINE OIL! It is too heavy and contains detergents and
other additives. 3-1 Oil, Marvel Mystery Oil, Sewing machine oil, or ordinary Air Tool oil (Harbor Freight #68094) works the best. I use high quality spindle oil for commercial
sewing machines in my shop for all lubricating jobs.
- Once the spring is soaked with oil, you may need to use a cloth towel to wipe off the excess oil.
- Clean the threaded hole in the starter housing and the mounting screw with brake cleaner and air. THESE THREADS MUST BE ABSOLUTELY CLEAN SO THAT THE THREADLOCK FIRMLY HOLDS THE
MOUNTING SCREW! If this screw gets loose, the starter will be eaten by the flywheel and any other moving parts in that area = $$$.
- Use a SMALL amount of white lithium grease on the center post that the pulley rotates on. More is never better.
- Make sure the cord is in the notch in the starter pulley.
- Place the pulley on the post/shaft. The spring is designed to automatically "hook" the slot at the base of post/shaft as you slowly turn the pulley. Most pulleys have a small
hole where you can see this happening. You may need to use a small screwdriver to "coax" the spring into the slot.
- Once the pulley is fully seated on the shaft, put a drop of blue threadlock on the screw and carefully thread it into the post/shaft. You do not want to get any grease on the screw.
- Once the screw is tightened to the proper torque (about 2-3 Nm), tension the starter spring by rotating the pulley using the cord that comes up out of the notch. Most starters
require 3-5 complete rotations. If you know how many turns it takes to take up all of the cord, rotate the pulley that many turns. Line up the notch with the cord exit hole and
release the cord. You want just enough tension to fully return the pull handle to the starter housing. It cannot flop around.
- Test the starter by slowly pulling out the cord to the end. It should NOT bind. If it binds towards the end, you will have to take one turn off the spring.
- Fully test the starter by smartly pulling it fully in and out to the end. It should be smoooooth and stop only when the cord if fully extracted.
Consider maintenance of the starter a routine matter. They wear out, get clogged with dirt, and parts break. There is no getting around it. Any binding of the starter spring
must be addressed promptly.
Pilots who fly in dusty or sandy environments will quickly gum up the starter internals.
3. A better pulley
The OEM Viadana pulleys from Miniplane are of poor quality. A superior pulley is the Harken which is available everywhere in the world. Here are the
details on better pulleys for your Miniplane (see section B4). There is no comparison between the Viadana and the Harken.