# Craftsman Bushwacker 31cc won't start



## aktweb (Apr 23, 2005)

I have inherited a Craftsman Bushwacker 31cc model 316-790111.

I really needed a weed wacker, and my dad gave me this one, but of course it won't start (that is why I am writing here !).

Here is what I know...
- champion plug, looks ok, gets a spark when I take it out and ground it
- fuel seems to get be flowing
- carb screen does not look gummed up
- piston/cylinder a little scarred, but not too bad
- zama carb, have removed both side plates, not sure what I am looking for, but things looked ok

What does the on/off switch on this thing really do ?

I confidently told my wife, it is either spark, air, or fuel. But I have failed to make figure it out, ugg.

Any advice ? I am off to buy a new plug just to rule that out permanently.

- Thanks, Andrew


----------



## hankster (Jan 1, 1998)

Since the piston/cylinder is scarred you will have to do a compression test. It should be 90psi or above. In the vast majority of cases if the piston/cylinder is scarred at all the compression will be too low and it will not run.


----------



## bbnissan (Nov 7, 2004)

If the piston checks out ok, take a look at the diaphram and make sure it's still soft and pliable. If it is stiff, you will have alot of trouble getting the trimmer to start.


----------



## gmanpop (May 22, 2005)

*Maybe A Little Help*

My Dad also gave me a used Craftsman Bushwacker weed wacker which would barely start after many rope pulls but then would not accelerate. I tried everything to get it to run at full throttle. After many attempts, my Dad suggested I pull the muffler off and burn the carbon out of the filter inside the muffler. I didn't even know it had a screen filter in the muffler. But sure enough, I pulled the muffler off and the screen was clogged solid. I made a small fire out of sticks and put the screen in it. After the fire was out, I scrapped the dried crusted carbon out and then put it and the muffler back on the weed wacker and it ran like a champ. I Have used the weed wacker for 5 years since then and have had to clean the muffler filter out one other time. It might be worth you checking yours out.


----------

