Stihl Ms391 Upgrades

Stihl Ms391 Upgrades Guide

A high-performance pro saw with many amazing features is the Stihl MS 391. If you have concerns for your safety, this is a saw you can continue to use for years.

The saw can cut diagonally and handle large, thick trees. You must agree that the saw is a premium piece of equipment, yet there are a number of Stihl MS 391 problems you can experience. The Stihl MS 391 frequently experiences broken starting procedures, unexpected power outages, oil tank leak issues, air filter issues, and a few more you can experience from time to time.

Luckily, most of these are easy fixes. In our guide, you can find the key issues that won’t let your saw perform at its best and what you can do to continue using your chainsaw. By the end, you’ll know more about making Stihl MS 391 mods to get back to your yard work. (Read 6 Plant Saucer Alternatives)

stihl chainsaw

What Are Stihl MS391 Upgrades?

Stihl chainsaw muffler modifications are often at the top of everyone’s list as a chainsaw tune-up.

However, you can find many other options for gains on your modded saw. It doesn’t take many items to make these changes; timewise, you can do this in an hour or so.

Here, you can see all the important parts needed to mod and upgrade your Stihl MS391.

Ensure you understand the parts, items, and more options you have before tossing your saw on your worktable to strip it down and start to mod your saws components.

Much of what is here can be included in regular services to save money and keep your saw in prime condition.

Stihl MS391 Upgrades and Pro Saw Muffler Mod Steps

Upgrading your Stihl ms391 will almost convert it to a pro chainsaw. The best time to upgrade your chainsaw is in winter because it can be out of action most of the time.

Here is the process below: how to upgrade your Stihl ms391.

stihl to fix

MS391 Upgrades Essential Tools Needed

Here are six tools essential for the modification of Stihl ms391. You’ll find many are what you use for your chainsaw services apart from a file if you are sharpening the teeth.

  • Rag
  • Flathead Wrench
  • Screwdriver
  • Steel Bowl
  • Torx Bits
  • Steel service kit for ms391

1. Chainsaw Preparation

  1. Visit the hardware shop and purchase a steel service kit. (The service kit comes with a new fuel filter, spark plug, and air filter.)
  2. Make sure to warm up your saw before beginning the modification process. Then, by placing the chain on the ground, the brake is applied.
  3. To start the saw warming up, squeeze the trigger and try to push it down.
  4. It requires five to ten minutes of priming to get it going.

2. Open and Clean Your Stock Saw

Firstly, wear thick gloves for your safety. Take out the chain and the bar carefully. Then open the fuel tank and pour it into a steel bowl. Soak a rag in fuel and clean up the machine.

You can use grease to clean your chain for the best results. Ensure you clean all the small spaces found as they say the devil is in the detail.

3. Change Fuel Tank, Air Filter & Spark Plug

Grab the fuel tank and pull it out using a long needle nose plier. Replace the old gasoline filter with a new one after carefully taking it out. After that, use a fresh sealant to seal the fuel tank.

To remove the old spark plug, use the wrench. After removing the old air cleaner and replacing it with a fresh air filter and spark plug, turn the engine clockwise.

4. Change Carburetor

Limiter caps are in the carburetor. The removal of the Stihl MS 391 carburetor must come first. The plastic screws above the carburetor can be removed using a screwdriver.

Contrary to other parts, carburetors don’t require significant alteration. Only if you plan to modify the muffler for a powerful engine should you replace the old carburetor.

To manage the fuel and air for a better-running engine, carburetors must be tuned, and you may need an expert or a dealer to do this to your saws stock carb.

5. Upgrade With Muffler Mod

  1. Pull the caps and Stihl ms391 muffler bolts out of the bark box using a flat metal screwdriver.
  2. The muffler can then be unscrewed with a T27 Torx. Next, remove the gasket and muffler underneath it gently.
  3. Clean up the muffler region and use a Dremel tool to cut out the muffler steel after removing the Stihl MS 391 muffler. It will deliver better exhaust with this.
  4. Create three slits and use a screwdriver to push them down to create the vent. Next, put the Bark Box and Gasket for the Stihl ms391 on.
  5. The muffler should then be carefully installed and tightened.
  6. The Stihl MS391 two-port muffler can be used for ventilation in place of a single muffler. The chainsaw would have more options for power from this muffler mod and turning it into a pro saw.

6. More Options In Garden When You Modify Bar & Chain

  1. You need to look around the market for a large bar that perfectly suits the Stihl ms391 without changing the balancing ratio overall.
  2. Wider trees might be chopped in one motion with a larger bar. The next step after adjusting the bar is switching to a correct chain fit.
  3. Remove the large screw, then install a new chain. Make sure the rakers with sharp teeth are placed on top of the bar.
  4. Finally, tighten the large screw. Put the cover on and attach the tiny screws.
  5. Use a wrench in the tiny holes of the bar to raise the hanging chain. If the chain becomes blunt, use a chain sharpening.
  6. Place everything back where it belongs, then tidy up the mess. Finally, start it off on the ground to test the chainsaw before using it on the tree.

More Options To Deliver Fix and Services To Stihl MS391 Chainsaw

1. Stihl MS 391 Starting Problems

Several problems can make starting difficult. When there are concerns with three items, you frequently experience trouble starting. Spark, fuel, and compression are the common three.

Fix

Check ignition, fuel, and compression.

  1. Check for spark by grounding the plug against the cylinder head. Look for sparks. Coils and ignition modules might fail, so keep a backup spark plug in case.
  2. And gas? You can try the carb with fuel. Afterward, check fuel lines, carburetors, etc.
  3. Compression-wise? If you don’t have a tester, pull up the saw with its starter cord; if it spools out and falls, it has internal damage. Remove the muffler and check the cylinder side. You’re responsible if it’s bad.

2. Chain Doesn’t Engage Because of Dirty Air Filter

The air filter is an essential component of the chainsaw that keeps debris out of the engine. You’ll notice less power and worse cutting performance when it gets clogged. (Learn How To Connect Two Garden Hoses)

If you don’t use your chainsaw enough, dust buildup inside and out can worsen this problem. Therefore, it is crucial to routinely clean your tool’s air filter and all other exposed surfaces.

Fix

Replace your air filter at least once a year to keep everything running smoothly. If multiple people use the same machine, make sure they all know when it needs replacing.

3. Chainsaw Loses Power

The Stihl MS 391’s power could unexpectedly fail. It is impossible to say what you are doing right now, given how important this time is. The engine will abruptly shut off, and the chainsaw’s rotation will be halted. If you’re working on large-scale woodworking projects, this could result in severe mishaps.

Fix

There could be several causes behind the issue. First, verify whether you are using Mobil and old oil. If so, modify it. (Read Condensation On Propane Tank Guide)

Determine if there are any air leaks. If you did, you could pull the muffler out and have a more oversized piston. Make sure you address these issues.

Similar Posts