Chainsaw Primer Bulb Temporary Fix

Need to use your chainsaw but cannot buy a primer bulb right away?

Don’t know how to repair the existing one?

Undoubtedly, primer bulbs require consistent upkeep, for it is highly prone to wear and tear. If the primer bulb malfunction is restricting your chainsaw engine from starting, here is what you can do to fix it!

Simple Steps to Fix a Chainsaw Primer Bulb for Emergencies

Generally, the primer bulb is located in line with the carburetor. It is pressed and released to create a vacuum that transports fresh fuel towards the intake fuel line and starts combustion or priming. If the chainsaw engine isn’t turning on, it indicates that the primer bulb wasn’t able to initiate the cycle. Follow these steps for problem identification:

  • See if the fuel tank is out of gas, fill it up before proceeding further.
  • Now, press the primer bulb, see if it is filling up with gas. Did nothing happen? Move to the next step!
  • Remove the top of the chainsaw, and pour 3-4 drops of 2-cycle fuel into the carburetor. If it runs that means the compression is working fine.
  • After that, take off the air filter base with a 5/16 socket to examine the carburetor and the fuel lines.
  • Loose nuts on both sides and take off the cover. You may see a broken fuel line there (the most common problem). The fuel line goes into the fuel tank through the fuel filter, so, it’s quite important element in completing the priming cycle you see.
  • To put the new fuel lines in, it’s better to remove the carburetor. Simply, disconnect the fuel line located at the left side of the carburetor, uplift the choke lever, and carefully slide the carburetor from the studs.
  • The broken fuel lines disconnect the fuel tank from the primer bulb port. To resume its functionality, remove the primer bulb port along with the fuel lines, and clean the fuel tank thoroughly, let all the debris shed off by keeping the chainsaw aside.
  • After cleaning, keep the chainsaw in the normal position, and start putting in the new fuel lines. Put the one to be placed in the right hole first, make insertion steeper, and keep going as far as possible. Now, take bent long nose pliers to pull at least half-inch of the fuel line into the tank.
  • Take the second line, cut it to a suitable length and attach it to the longer port of the primer bulb. (Remove the primer bulb first, if it’s clipped, unclip it. Otherwise, open up screws on both sides)
  • Now, put the fuel line in the fuel filter (using the same technique as for the return line) and pull the line out of the fuel tank as much as you can. Once it’s completely out, cut it straight, put a fuel filter in the end and insert it back into the tank.
  • Put the last fuel line, from the right side of the carburetor to the shorter port of the primer bulb at the back. Place the carburetor back. Replace the air filter, and cover up the chainsaw.

Put some gas in the fuel tank. Press the primer bulb multiple times, see if it fills up the gas. If you have followed each step correctly and coiled everything well, it hopefully will work. Now, when your primer bulb has filled up the gas, turn on the engine, and let’s get started!

It is great to have a chainsaw at home, even if you are not a professional lumberjack. You can do your woodwork all at home without much headache. However, often your chainsaw may come to a halt and not work. Repairing it from a mechanic will cost you time and money. Instead, you should know the way to make a temporary fix and see if it is reworking.

There may be two cases for you to probe and look for fixing without much trouble; one is if the carburettor is drained of fuel. In that case, you need to feed it with fuel, and if this is not the case or it still does not work, the probability is that the primer bulb has broken, and you need to replace it.

Fixing the primer bulb:

There are three steps to the process. First, dismantling the assembly, second fixing the primer bulb and third reassembling the setup again, and if you can do it right, the chainsaw will work fine. Here is the know-how.


Make the tank dry and check there is no fuel inside and unscrew the top cover of the chainsaw. This will help you take out the saw from the body. Unscrew the side and get off the starter assembly. Next, take off the air filter socket and the air filter. Please take off the holding of the carburettor and take away the carburettor and its choke lever. The primer fuel line is to be removed from the carburettor next. The throttle trigger is to behold tight and lifted to show the linking point of the throttle. The link has to be pulled off and disconnected. Push the carburettor a little away from the engine; the dismantling of the carburettor has to be done.

 Taking out the primer bulb:

The primer bulb has to be removed from the carburettor.  Putting a screwdriver in the holder of the primer bulb and pressing it will make the bulb come out. Then, with a plier with elongated tongs, the fuel lines must be taken out from the primer bulb. There will be two fuel lines.

Fixing the primer bulb.

Detect the intake and the return ports of the primer bulb. Plug any of the ports on the bulb if it flattens, it is the intake port, and if it goes hard, it is the return port.

Now connect the intake line (the line which is shorter in comparison) to the intake port of the bulb. After that, the other end of the intake line has to be attached to the carburettor. Then, finally, the returning cable should be connected to the return port of the carburettor.

 Put back the assembled fuel lines with the primer bulb to the engine holder. Press to put it in the right place of the engine holder.

Reassembling the Chainsaw:

Follow the reverse steps you have dismantled. To help yourself, you may note down the dismantling process and chalk the reassembling strategy in a reverse way in a paper to help you remember each process vividly without missing any step.


Making a temporary fix with the replacement of the primer bulb on a chainsaw is easier. Most of the time, it saves the hassles of taking it for repair and saves you dollars. Above that is the satisfaction that you have repaired it of your own. So why wait for someone else to fix your chainsaw when you can do it? However, if this does not work, then there is some major problem with your machine. It would help if you then thought of taking it for a repair.

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