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Lawn-boy will not start

#1

D

denwayanderson

Hello all,

I have a lawn boy push mower that will not start. I have changed out the cd pack and cleaned the carburetor inside and outside. I recently had a plug that was too long and I think it hit the piston, however, there does not seem to be any damage to the piston head as observed from the spark plug hole.

Any suggestions would be appreciated.


#2

Two-Stroke

Two-Stroke

What is the model number?

And what's a "cd pack"?


#3

Fireman 123

Fireman 123

denwayanderson said:
Hello all,

I have a lawn boy push mower that will not start. I have changed out the cd pack and cleaned the carburetor inside and outside. I recently had a plug that was too long and I think it hit the piston, however, there does not seem to be any damage to the piston head as observed from the spark plug hole.

Any suggestions would be appreciated.
Click to expand...

Have you verified if the new coil is throwing a spark? Is the clearance between the coil and flywheel set right? What does the compression feel like? I'm guessing it's a 2-stroke? While you're at it, pull the muffler and check the exhaust ports for any carbon build-up. Two things the 2-stroke engines need to run are compression, and clean exhaust flow. Thats how they pull their fuel. I hope I was of some help. Good luck


#4

D

denwayanderson

Yes, the coil is showing a spark through the spark plug. when I pull the starter rope I can actually hear the compression from the cylinder, but will not start. Yes, it is a 2 stroke engine(gas/oil). I have not checked the muffler, but I will check for carbon buildup. Thanks for your help


#5

D

denwayanderson

Two-Stroke said:
What is the model number?

And what's a "cd pack"?
Click to expand...
cd pack is the coil, plug wire combo

model number is 10545

Thanks


#6

Fireman 123

Fireman 123

denwayanderson said:
Yes, the coil is showing a spark through the spark plug. when I pull the starter rope I can actually hear the compression from the cylinder, but will not start. Yes, it is a 2 stroke engine(gas/oil). I have not checked the muffler, but I will check for carbon buildup. Thanks for your help
Click to expand...

Ok. Thanks for giving the model #. Check to see if the spring on the air vane governor is out of adjustment. The thumb-wheel it's attached to is where you set the throttle. Right to increase. Left to decrease. It will make a clicking sound when you do so. I would tighten it snug, and then back it off a couple clicks. At least I've found it works for me. Good luck


#7

Fireman 123

Fireman 123

Fireman 123 said:
Ok. Thanks for giving the model #. Check to see if the spring on the air vane governor is out of adjustment. The thumb-wheel it's attached to is where you set the throttle. Right to increase. Left to decrease. It will make a clicking sound when you do so. I would tighten it snug, and then back it off a couple clicks. At least I've found it works for me. Good luck
Click to expand...

Reason I say that is because after putting a new carb on my 8243 I pulled to my hearts desire with nothing until I found how to set the gov!


#8

Two-Stroke

Two-Stroke

Fireman 123 said:
Ok. Thanks for giving the model #. Check to see if the spring on the air vane governor is out of adjustment. The thumb-wheel it's attached to is where you set the throttle. Right to increase. Left to decrease. It will make a clicking sound when you do so. I would tighten it snug, and then back it off a couple clicks. At least I've found it works for me. Good luck
Click to expand...

That's a handy little fact. Thanks for posting that, Fireman123.

Getting back to the original question, I would try priming the engine by squirting a little gas/oil into the carb. It should fire and run briefly if everything is OK with the ignition system.

If it does fire the problem is in the fuel system.


#9

D

denwayanderson

How is the best way to pull the under deck muffler. I have tapped with rubber mallet and it will not give. if there a clip cholding the mulching flange to the crankshaft? I can not see one..

thanks

Dennis


#10

Fireman 123

Fireman 123

denwayanderson said:
How is the best way to pull the under deck muffler. I have tapped with rubber mallet and it will not give. if there a clip cholding the mulching flange to the crankshaft? I can not see one..

thanks

Dennis
Click to expand...

If you're talking about the blade adaptor, the best way I've found to remove it is by leaving the nut threaded onto the shaft and tapping it with a hammer while prizing on it. It will eventually give just be careful not to damage the threads or the adapter. After it's removed, you'll find 3 bolts holding the muffler to the engine/deck plate. After the muffler is removed you'll find the 3 exhaust ports.


#11

D

denwayanderson

Hello all,

I checked the governor assembly and looks like the spring was out of the black part of the vane assembly. I placed the spring back in and rewould it , but still does not work. Is the spring a close knit unit or comes together with the vane assembly.

any help would be appreciated.

Dennis


#12

B

buzzcut

some times when you hit a object while mowing, or a to long sparkplug you may patially shear keyway on fly wheel you have spark but it is out of time because keyway and fly wheel are out of proper postion this is something you should try to look at it may be your problem. hope this helps been there !


#13

D

denwayanderson

To pull the flywheel will I need a mechanical puller to remove the flywheel and replace the keyway? Thanks for your input.

Dennis


#14

S

SouthTech

I would check compression before doing all that.... Easy test and tells you if all that other stuff is worth trying


#15

D

denwayanderson

SouthTech said:
I would check compression before doing all that.... Easy test and tells you if all that other stuff is worth trying
Click to expand...

What is best way check compression


#16

S

SouthTech

denwayanderson said:
What is best way check compression
Click to expand...


It痴 a tool that replaces the spark plug. Install it crank on it a few times then read the psi. If you don稚 want to invest in one some part houses will loan are rent one, just call around. For a lawn bow 110 -120psi is the lowest you want anything below 100 will be really hard to start if at all.

Here is an example/link of the tool I was referring to

COMPRESSION TESTER /


#17

D

denwayanderson

SouthTech said:
It痴 a tool that replaces the spark plug. Install it crank on it a few times then read the psi. If you don稚 want to invest in one some part houses will loan are rent one, just call around. For a lawn bow 110 -120psi is the lowest you want anything below 100 will be really hard to start if at all.

Here is an example/link of the tool I was referring to

COMPRESSION TESTER /
Click to expand...

I borrowed a compression tester tool from an auto mechanic, however, there is no compression registered, will the auto compressor tester work with a lawn mower, due to shank size that goes into bore of head. the cylinder head of mower requires short shank adapter and if I place the whole adapter it will hit the piston, so I had to loosen it just enough so the piston would not hit. Is this an adequate to test compression. unable to locate a shorter adapter. thanks


#18

S

SouthTech

denwayanderson said:
I borrowed a compression tester tool from an auto mechanic, however, there is no compression registered, will the auto compressor tester work with a lawn mower, due to shank size that goes into bore of head. the cylinder head of mower requires short shank adapter and if I place the whole adapter it will hit the piston, so I had to loosen it just enough so the piston would not hit. Is this an adequate to test compression. unable to locate a shorter adapter. thanks
Click to expand...

If you got 0 compressions I would say that the test was no good. The tool I was referring to usually just screws into the same whole the spark plug goes in. It should not come in contact with the piston. If this is what youæ±*e doing spray some soapy water around the threaded part of the adapter. If you have leak it will create bubbles and the test is no good. If you don稚 get bubbles and you fill the test is good then you have internal engine problems.


#19

A

a.palmer jr.

I'll probably start a fight here, but the carbon build-up is a good reason to use a good brand of synthetic 2 cycle oil. I run Klotz Techniplate at 32:1 in my Lawn Boys and have had no carbon. Yes, it's expensive but I hate tearing them down and finding a ruined piston because of carbon getting between the piston and cylinder wall. I've run Klotz in 2 cycle engines for several years and haven't had a oil related failure.


#20

E

earthworm

a.palmer jr. said:
I'll probably start a fight here, but the carbon build-up is a good reason to use a good brand of synthetic 2 cycle oil. I run Klotz Techniplate at 32:1 in my Lawn Boys and have had no carbon. Yes, it's expensive but I hate tearing them down and finding a ruined piston because of carbon getting between the piston and cylinder wall. I've run Klotz in 2 cycle engines for several years and haven't had a oil related failure.
Click to expand...

Good advice.
IMO, you can run a 50 to 1 when using a quality synthetic.
Are there any acceptable substitutes for the Klotz ?
I use the old "thumb in the hole " trick to check engine compression...this works OK, to an extent.


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