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Murray Weedeater Won't Start

#1

S

solefate

Okay, so I have a 2013 M2500 Murray Weedeater 41ADZ01C758. I have cleaned carb, gaskets and jets look good. Have changed fuel mixture, and lines/primer bulb and such are fine. Have also replaced with known good spark plug. Guy said it was working fine one day with no troubles, and then just wouldn't start the next. Just for the experience, I decided to dismantle entire thing, to check spark plug line and the shutoff wire inside the unit. However, I am stuck at the clutch assembly. I cannot get the piece apart. Is there a screw in there or is it supposed to pop off? Also any other ideas are welcome :thumbsup:
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#2

I

ILENGINE

There is a torx head screw down inside the clutch. But before you get too far into this thing can you get us a compression reading.


#3

A

angellonewolf

If you have not got a compression tester it's not exact but put the weed eater on the ground with not holding it just lay it down and pull the cord not fast like your starting it just lift it up by the pull cord if when lifting up can pick up the unit by the pull cord then there is an amount of compression if it stays on the ground when pulling the compression not enught

P's I think reading the fourms you need a certain type of tester for small engines (this is from memery I'm sure someone will core me on this if I'm wrong)


#4

I

ILENGINE

Angellonewolf, any automotive compression tester can be used. There is nothing special about it for small engines. the only thing you may need to watch is some of the newer small engines use a 10mm spark plug thread as opposed to the normal 14mm thread.


#5

primerbulb120

primerbulb120

I would pull off the muffler and check for scoring on the piston and rings.


#6

A

angellonewolf

Ok just thought I seen it some where but did say some one will correct me lol


#7

S

solefate

ILENGINE said:
There is a torx head screw down inside the clutch. But before you get too far into this thing can you get us a compression reading.
Click to expand...

angellonewolf said:
If you have not got a compression tester it's not exact but put the weed eater on the ground with not holding it just lay it down and pull the cord not fast like your starting it just lift it up by the pull cord if when lifting up can pick up the unit by the pull cord then there is an amount of compression if it stays on the ground when pulling the compression not enught

P's I think reading the fourms you need a certain type of tester for small engines (this is from memery I'm sure someone will core me on this if I'm wrong)
Click to expand...

primerbulb120 said:
I would pull off the muffler and check for scoring on the piston and rings.
Click to expand...

All noted, going to see if I can't go and buy one today. Been planning on working on small engines a bit more so won't hurt for future problems. Also, if there is scoring, what would have gone wrong to cause it?


#8

B

bertsmobile1

angellonewolf said:
If you have not got a compression tester it's not exact but put the weed eater on the ground with not holding it just lay it down and pull the cord not fast like your starting it just lift it up by the pull cord if when lifting up can pick up the unit by the pull cord then there is an amount of compression if it stays on the ground when pulling the compression not enught

P's I think reading the fourms you need a certain type of tester for small engines (this is from memery I'm sure someone will core me on this if I'm wrong)
Click to expand...

The other thing you have to watch with small engines is how long the adapter is.
When you only have 21cc if it screws down further into the head than the spark plug then you end up with a higher reading than you should and if it is short you end up with a lower reading which is why the numbers are always bit rubbery and why a leak down, vaccuum and applied pressure tests are better than a strait compression reading.
However if you are monitoring an engine over time it does not matter what the actual numbers are what you are looking for in that case is the difference between then & now and it should always be done with the same meter.


#9

M

Mikel1

Does it have spark?


#10

S

solefate

bertsmobile1 said:
The other thing you have to watch with small engines is how long the adapter is.
When you only have 21cc if it screws down further into the head than the spark plug then you end up with a higher reading than you should and if it is short you end up with a lower reading which is why the numbers are always bit rubbery and why a leak down, vaccuum and applied pressure tests are better than a strait compression reading.
However if you are monitoring an engine over time it does not matter what the actual numbers are what you are looking for in that case is the difference between then & now and it should always be done with the same meter.
Click to expand...

Mikel1 said:
Does it have spark?
Click to expand...

Okay so, I ordered a tester, and I believe I ran across what berts was saying about being too short/too long. It only read around 50, but it read about the same on another known good weedeater. And yes it does have spark. The carb is good, it worked on the other weedeater. What I did notice however, is there is never any gas on the spark plug. Even after 20+ pulls/primes, the spark plug will be bone dry when removed. Is this something to do with the piston?


#11

I

ILENGINE

Just FYI, the murray trimmers are made my MTD and the reject compression on their products is 90 psi, Below that and you are done. Some of the newer 4 stroke trimmers do have compression release, so that may be a factor.


#12

S

solefate

ILENGINE said:
Just FYI, the murray trimmers are made my MTD and the reject compression on their products is 90 psi, Below that and you are done. Some of the newer 4 stroke trimmers do have compression release, so that may be a factor.
Click to expand...

Yeah, I figure it's just because I bought a cheap tester. I tested it on an echo trimmer that runs great and it only read 55.


#13

primerbulb120

primerbulb120

solefate said:
Even after 20+ pulls/primes, the spark plug will be bone dry when removed.
Click to expand...

Remove the spark plug, spray some starting fluid through the hole directly into the cylinder, put the spark plug back in and try to start it.


#14

S

solefate

primerbulb120 said:
Remove the spark plug, spray some starting fluid through the hole directly into the cylinder, put the spark plug back in and try to start it.
Click to expand...

No go. I found another murray to test, and this one has about 15 lower psi on it.


#15

primerbulb120

primerbulb120

Pull the muffler off and check for scoring. If the piston and rings look good, leave the muffler off and try to start it again with starting fluid sprayed directly in the cylinder.


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