# Another darn Craftsman 31CC Weed Trimmer question



## tp121 (Apr 24, 2006)

I have read a few posts related to this trimmer model here- I too had a line come loose/tear off my 31 cc weed trimmer.

When I took the line off, I decided to replace everything. Primer bulb, and hoses. Of course, I forgot how the lines were run. 

I bought a rebuild kit from Lowes made by MTD, which has all the lines, and a new primer bulb.

I have 2 lines out of the tank..one is a return, one is the filter/supply line.
I have 2 nipples on the carb..one is at the top and is a straight line, the other is on the bottom, and is an elbow/90 degree fitting. The carb has a metal plate with 4/6 screws on the left side, and a plate with one big screw on the right side (looking from the back)

I have hooked this thing up numerous ways, and not only can I not get it to feed gas, but it looks like there is air in the lines.

I'm hoping someone can help me- if not I am just gonna bite the bullet and drop 200 bucks on another new one. Thats how frustrated I am with not being able to get this thing to run.

Help me?


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## VIR3NT (Jan 14, 2006)

dont go buy a new one, this is one of the most simple problems.
When you say you got a new primer bulb did you get a whole new carb? If not i suggest geting carb cleaner and tearing it down and soaking it. Making sure the nipples are clear of any obstructions. 

Where the hoses go:
Intake (w/ filter) goes on the 90 degree spot (probably)
- to be sure of this attach the intake tube to the straight nipple and pump the bulb with no line on the 90 degree nipple and see if it squirts out gas. If it does attach your other tube to it (or vice versa).

If its a new carb you never know how it is tuned. Turn the hi/lo jet screws in all the way and then back them out about 1.5 - 2 turns. This will get you started to make more fine tuning adjustments. Make sure you know which screw is which. Tune the hi and lo jets the same at first. dont worry about your idle screw for now. don't mess with the fastening screws either, the hi/lo jets should have springs between the head and the carb.
Good luck


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## tp121 (Apr 24, 2006)

Thank you for the reply.

I didn't get a new carb, becuase this one was running fine before I replaced the hoses.

I also can't figure out why it looks as if there is air in the lines?

Also, the long nipple off the primer bulb goes to the return/vent line in tank, and the short nipple goes to the line going to the top nipple on carb?


Any ideas?


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## VIR3NT (Jan 14, 2006)

There is natrually a little bit of air in the lines, just as long as there is not more than small bubbles. If you want to reduce the amount of air in the lines make sure the filter is submerged in the gas in the tank.

As for short/long nippeles, i dont know the individiual carb. However, try my tip about pumping the primer bulb with only one hose on it, if nothing comes out, put the line on the other spot and pump it. if it spits out gas put the return line on it and you're setup correctly.
The return line is usually the clear one and the intake is usually the black line with the filter on the end. However, the clear/black thing isn't always true.

If you can, take a picture of the carb the way you have it setup, It'll help me understand what you're looking at.


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## tp121 (Apr 24, 2006)

I will try and get a pic tonight if possible.

Can't thank you enough for all your help. I was ready to just trash it in the dump. Seriously.

Stupid, I know..but I can only take so much frustration. My time is worth something at some point.

Thank you again!


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## hankster (Jan 1, 1998)

What model is it? I can then double check when I go into work.


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