My lawnmower just stopped starting the other day I replaced the battery and it didn’t help so I replaced the Starter Solenoid which also didn’t help . I ordered a new starter waiting for it to come in . The mower just clicks when I try to start it the starter spins but I noticed the starter gear is not retracting unless I manually spin the motor . I’m new to this so looking for any other ideas I could try or If it sounds like a bad starter ?
That is how it is supposed to work
1) acan you rotate the engine by hand ?
2) if yes above then remove spark plug & see if the engine spins
3) if yes above then check the valve lash & also check for decompression .
That is how it is supposed to work
1) Can you rotate the engine by hand ?
2) if yes above then remove spark plug & see if the engine spins
3) if yes above then check the valve lash & also check for decompression .
These engines are for valve clearance to get out adjustment causing the ACR (automatic compress release) to become inoperative. They also know for the ACR on the camshaft to fail so this why you must check for the ACR bump at TDC compression on the intake rocker once the clearances are set to spec. IN .003-.005 EX .005-.007
#5
Bc54
Ok this is beyond my skill level so I will have to find a repAir shop. I can spin it freely . Spins normally without spark plug . Without the spark plug I can hear it decompress when I spin the motor. Does this mean camshaft is ok ? Really hoping Valve just need adjusting so I can clear up my yard before snow hits
#6
StarTech
No it just air/fuel mix is escaping from the spark plug hole when the plug is removed.
#7
Bc54
Ok thank you I will stop throwing parts at and let a professional look at it
Set the valve lashes on both valves
Then watch the rockers moving as you rotate the engine by hand
You should see the valves open & close as the piston goes in & out .
If the cam lobes are OK then the the inlet should open , close & as the piston gets near the end of the stroke the inlet will open a tiny bit again, this is the automatic decompression happening .
If this does not happen then the cam is gone
Getting a cam done by a workshop ends up costing about 3/4 of a replacement engine so not a good idea
There are plenty of service manuals and quire a few videos on how to do the job.
#9
Bc54
Thank you going to attempt to fix it with a friend . If it’s a cam shaft couldn’t find anyone local who had a oem one available so will take a little longer to come in but figure it’s better to go with the oem one .
#10
shadetree#1
Just a hint:
Several you tube videos about how to first check and adjust the valve lash on that Single cylinder Briggs OHV Intek engine. (a picture is worth a thousand words)Watch more than one.
Note that the valve lash is adjusted when the engine's piston is 1/4 inch past TDC.
Also instead of immediately messing around adjusting the INTAKE valve lash (the ACR is on the INTAKE valve) if you find it too be more than .003-.005, if for example you find it to be .008, just locate a .005-006 feeler blade and slide it under the rocker to reduce the valve lash to .002-.003 (without loosening the adjustments)and hold the feeler blade under the rocker and try cranking the engine over with the spark plug re-installed, BUT leave the plug wire off so the engine does not start. If it still hangs on the compression stroke you then know you are just wasting time adjusting the valve lash to minimum specs. If you have to go to .001 lash or less to for the engine to crank the ACR is broken internally.
The ACR is not operating.
If it cranks over ok with the feeler inserted set the valve lash to specs and then install the valve cover and the spark plug and crank test. The engine will crank over little bit harder when spark is introduced.
I've seen some of them Briggs 31 and 33 series engines that the valve lash on the Intake had to be .002--003 for the ACR to operate when the engine is cold. They would compression lock at .005, especially on a cold engine on a very cold day. I suspect this is due to a worn ACR not opening the Intake valve open quite enough and the valve lash being just little bit more on a cold engine. I would have to set the INTAKE valve lash to a very snug .003 to get good ACR operation.
#11
StarTech
I always set OHV at the minimum clearance specs as they tend to open up due to wear. I also adjust using an alternate method
#12
shadetree#1
StarTech:
I always set OHV at the minimum clearance specs as they tend to open up due to wear. I also adjust using an alternate method
What is your alternate method?
#13
StarTech
One valve at a time that way I don't have hunt a measuring tool or remove the spark plug(s). Just sure the rocker being adjust is the one that the valve is fully closed. I know it is different but I am set in my ways from the auto industry.
#14
Bc54
Thank you for the advice. It was the camshaft. I was able to fix it today it wasn’t that bad
