How To Repair your Recoil Starter

by Steve Pond

Pull-starters used to be temperamental and were stigmatized by experienced nitro nuts as being performance robbing and unreliable. Thanks to the huge "explosion" of nitro RTRs, pull-starters are more reliable than ever, and there’s nothing more economical or convenient. Pull-starters still need maintenance though. This article is dedicated to maintenance and repair techniques for your pull-starter.

The components of a pull-starter typically include the housing, starter cord, spool, recoil spring, one-way bearing and starter shaft. The parts configuration and the installation order may change, but these are the essential elements. Individual details vary, but the typical pull-starter contains these six components: • Housing • Pull-cord • Spool • Recoil spring • One-way bearing • Starter shaft

Anatomy of a pull-starter When you pull on the T-handle that’s attached to the end of the starter cord, the spool on which the starter cord is coiled starts to spin. The one-way bearing in the center of the spool locks on to the starter shaft to turn it. The starter shaft is indexed to the engine’s crankshaft, which cycles the piston through the cylinder to fire up the engine (assuming the glow plug is glowing and there’s fuel in the system). After the engine starts, the starter shaft spins freely in the one-way bearing. The one-way bearing is key. For a pull-starter to operate properly, the one-way bearing needs to lock on to the starter shaft to facilitate starting, and then it must allow the starter shaft to spin freely after the engine has started. The latter isn’t usually a problem, but it’s common for a worn one-way bearing to slip on the starter shaft and make starting erratic or even impossible.

A worn starter shaft is as much to blame for a slipping starter as a worn one-way bearing. You should plan to replace both the starter shaft and the one-way bearing to restore reliable pull-starter operation. Slipping starter A bad one-way bearing usually reveals itself by slipping on the starter shaft. This is when you pull on the starter cord, and if the one-way bearing grabs at all, it often isn’t enough to start the engine. This can usually be cured by replacing the one-way bearing, but the replacement bearing never seems to last as long. The starter shaft is often the root of the problem because some are not made of properly hardened steel. This causes the starter-shaft diameter to wear down more quickly, and that causes the one-way bearing to slip. It’s best to replace the starter shaft when you replace the one-way bearing; that way, you’ll get at least as much life out of the new parts as you did out of the original. When a pull-starter comes apart like this in your hand, the best solution may be to buy a replacement. Installing the spool with an attached recoil spring usually requires indexing one end of the spring to the housing. Tread lightly here, as the spring can easily work its way out of the spool before it’s fully seated in the housing. If it does, you’ll have to start all over again. Rewinding a recoil spring may require that you wind it by hand or around the bottom of the starter spool. Either way, this is the most trying part of pull-starter maintenance. You must maintain a firm grip on the spring to prevent it from uncoiling violently. Always protect your eyes when doing this type of work because there’s no telling where the spring will go if it gets away from you. Some starter designs require that you coil the spring before you install it in the housing. Get a firm grip on the coiled spring with a pair of needle-nose pliers and then place it in the housing. In some starters, the recoil spring can be installed inside a recess in the spool. Rewinding the spring with this arrangement is easier than in others, but it can still be challenging. There may be holes in the spool that you can slide a hex wrench through to hold a tightly wound recoil spring in place while you line it up to be installed in the housing. This is the most unstable method, but sometimes, it’s the only option besides replacement. Sticking recoil action If the starter doesn’t recoil properly, it could be one of two things: there may be dirt or debris in the starter housing that prevents the spool from recoiling the cord, or the recoil spring has broken or pulled free from the housing or spool. If it’s the former, a little maintenance will clear it up. If it’s the latter, you will have to repair or replace the pull-starter. Repair or Replace? There are certain situations in which it just makes sense to buy a new pull-starter. What appears to be a simple fix might not be that simple. After you’ve opened the pull-starter housing to replace the starter cord or fix/replace the recoil spring, you may wish you had just gone for the new recoil unit. But if a repair is your only option, here are a couple of pointers on how to fix these two most challenging parts of a pull-starter. Rewinding the recoil spring Removing the spool from the pull-starter will tell you whether a new recoil spring is needed. The problem is that the recoil spring tends to burst out of the housing and becomes a tangled mess. Whether you need a new spring or not, you’ll have to wind the recoil spring onto the spool so you can put everything back where it belongs. This will test your patience like nothing else, but it can be done. Tightly wind the recoil spring around the hub on the spool until the spring is relatively tight. There’s usually a pair of aligned holes in the spool through which you can insert a skinny tool such as a hex wrench. This holds the end of the wound recoil spring in place while you install the spool in the housing. This requires a delicate touch because the recoil spring can burst into a tangled mess again without much provocation. Be prepared to try this about half a dozen times; if you can do it during the first couple of tries, you’re above average. The other way to install a recoil spring is to neatly coil it inside the pull-starter housing, then place the spool over the spring. This isn’t always possible because it’s often difficult to align the recoil spring with the spool, but if you can make it work, this technique is sometimes easier than winding the spring on the spool. Wind a few turns of cord onto the spool, then pull the cord and hold it while you wind a few more turns of cord onto the spool. Repeat this process until the spring recoils the full length of the starter cord but not more than that. Both methods may sound simple, but if you make one wrong move, that cobra of a recoil spring will uncoil itself faster than you can say “#@&$%!”

One Way to Treat a One Way Successful starting requires the starter’s components to be intact and functioning properly, but it’s the one-way bearing that’s often the most critical; if the one-way doesn’t lock on to the starter shaft, you’ll go nowhere. Oil doesn’t usually harm a one-way bearing, but it may cause a bad one-way to slip. The only time oil is a bad thing for a one-way is when it attracts dirt and you don’t clean it. It’s a good practice to clean the starter assembly at least a few times during the season; clean it more frequently if you use the car or truck in a very sandy or dusty environment. Here’s what to do: • Take the starter housing out of the engine. Make certain the spool doesn’t come out of the housing; if it does, the recoil spring will explode, and you’ll have to rewind it (the most annoying repair in the history of RC). • Clean the housing, spool, one-way bearing and starter shaft with a nitro spray cleaner. • When everything in the housing is dry, place a few drops of oil inside the one-way bearing and on the starter shaft, and reinstall the starting housing. This maintenance will help prevent the shaft and the one-way bearing from being damaged by excess dirt. The aforementioned cleaning can also help to cure a slipping one-way that has been saturated with oil from the fuel. The fix is usually temporary, however, because the root of the problem lies elsewhere.		Cleaning the pull-starter components, especially the one-way bearing and starter shaft, helps to minimize slipping of a worn starter assembly.
		Just a drop or two of clean oil is all that’s needed to lubricate the one-way bearing inside the pull-starter.

Whether it happens over time or because of a rewinding attempt, a loose starter cord is easy to fix. Fixing a Loose Starter Cord Have you ever seen a pull-starter that doesn’t recoil enough to pull the cord taut and keep the starter handle in place? This is usually because the starter has repeatedly been pulled out too far and, over time, that fatigues the recoil spring. To fix the droop, just pull an inch or two of cord out of the top of the handle (to restore spring tension) and tie a new knot. You’ll be hating life if that knot unties itself and the cord disappears into the housing, so make it a tight knot and put a drop of CA on it to make sure it stays tied. If you don’t like the idea of shortening the starter cord, you’ll have to open up the starter to make the fix. Pull the starter handle until there’s tension on the recoil spring. Then hold the spool with your thumb and gently work the starter cord back onto the spool through the gap between the starter housing and spool. Repeat this process until you can release your thumb from the spool and the tension on the recoil spring will hold the starter handle upright.

Pull a length of starter cord from the o housing, and then hold the spool firmly in place with your thumb so it can’t recoil. Then fish out the slack from inside the housing. Next, fish out the cord around the spool without letting the spool recoil just yet. Repeat until there’s adequate tension on the starter cord when it’s recoiled. Above: After you’ve completely reassembled the starter, install any retainers to keep the spool in place. After you’ve done this once, you won’t want to do it again anytime soon. Above Right: A properly assembled pull-starter will recoil long enough to keep the starter handle stationary, but it wo't have so much tension that the spring binds as the starter cord is drawn out of the housing. TRy it out before installing it on the engine, but be careful not to let the spool jump from the housing. You can also fix a loose starter cord while the starter is still installed on the engine. Pull a length of cord from the starter, cut off a section of cord to shorten it, and then tie a new knot. Be sure to tie a temporary second knot below to prevent the cord from recoiling into the housing because once that happens, you’ll have to start over.

Original Page

Source :

Banners are for your personal interest, so use them and  you will also support this website 

 Les bannières sont pour votre usage personnel, utilisez-les et vous supportez ce site par la même occasion