Having Starter problem, among other things

ljms

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Hi All, This is going to be a long post, please bear with me. :)My Grandkids acquired a 2012 Bolens, model13w1762F065. This is a 38" lawnmower with a B&S 13.5hp. When they got it the deck was pretty much shot and they wanted it just to drive around and use as a tractor and just something to drive around the yard and mud around. They had it for quite some time when it started to be hard starting. They would jump start it but with the battery alone it would stop when it hit the top of the compression stroke and not turn over enough to start. I figured a bad battery, wrong. Same thing with a brand new battery. But this whole time it would turn over very fast when I removed the spark plug. So Google says valve adjustment. Did that twice along the way to just be sure I got it right. That didn't work So I thought perhaps a bad starter. So I took it to a starter repair shop and when he took it apart he said it shows absolutely no signs whatsoever of a bad starter. He said it looked like it was new, no burn marks , carbon dust or signs of a heated starter or windings. He said he could sell me a new one but he was absolutely sure the starter wasn't the problem. He told me to take a voltage reading at the starter when trying to start it.He says there should be very little drop in voltage. Well It showed 12.7 volts at the battery and 2.6 at the starter. So it seems like I am losing voltage somewhere. So I jumped the starter directly from the battery and it did the same thing, wouldn't crank pass the compression stroke.
I am really at a loss. I originally was going to by-pass the safety switches since the deck is no longer on it. Several Google searches point to the solenoid. So looking for the solenoid I found it in the most un-accessible areaup under the seat among all the rods and linkage. So I have removed it along with the wiring harness so I could check it out. Now I am convinced I need to get down to the bare bones wiring, just enough to start, run, and shut off when it supposed to. My question , Is there any hope of getting the wiring down to some thing more basic? I need a starting, charging, ignition, and carburetor solenoid. Is it possible or a waste of time? Thanks for your help and input.
LaVern
 

bertsmobile1

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The decompressor is not working
Take the rocker cover off remove the spark plug and do 2 full rotations of the engine.
watch the rockers.
You should see one of them open very slightly just before TDC on the compression stroke.
If this is not happeningand the valve lash is set correctly then the cam is shot and needs to be replaced.
However triple check you have adjusted the valves properly .
 

ljms

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Hi, Thanks for the info. I thought I did get the valves adjusted right, but..... Do you not bring the piston up to TDC with both rocker arms loose showing it is on TDC? Or where should the piston be when adjusting the valves? I watched a couple of videos and maybe that's where I went wrong. I thought TDC was where the adjustments were made. Speaking of settings, is .003 intake, .oo4 exhaust correct? Thanks again. Will appreciate any clarification.
LaVern
 

Scrubcadet10

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while most engine makers do have a recommended valve lash adjusting procedure, I've done it this way with never a problem.
Intake valve OPEN (intake spring depressed) adjust EXHAUST, exhaust valve open, (exhaust spring depressed) adjust intake.
 

bertsmobile1

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Yes.
For Briggs the factory recommendation is 1/4" past TDC on compression stroke ( both rockers loose )
I usually watch the valves and when the inlet closes you are the compression stroke.
Some times the valve lash can be huge or there can be crud holding a valve open so just relying on a loose rocker is not good enough
 

ljms

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Again thanks for all the input. One thing that has been addressed is the drop in voltage at the starter. Should there be such a sharp decrease. From 12.7 to 2.6 volts seems to be drastic, and in my mind points to a short somewhere in the wiring? Of course it could mean something completely different and if so please feel free to educate me.

Also how complicated is it to rewire the mower using only the bare necessities and eliminate all the switches that are no longer needed? Thanks again for your help, all input is greatly appreciated.
LaVern

P.S. I am not getting email notifications for these responses. I think I have my preferences set up to receive them but so far I have only seen these by coming back to the forum.
LJS
 

ljms

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I see now that I mis-typed in the above posting. I typed ,"One thing that has been addressed is the drop in voltage at the starter. " Should have read, "hasn't " been addressed yet. So I'll try again. Is a voltage drop of 12.7 to 2.6 volts normal? The way I measured it was clipping the positive lead of voltage meter on the terminal on the starter, and the negative lead to ground and watched the meter when I tried to crank it. I think that is what the starter repair guy said to do it. Again thanks for your jelp.
LaVern
 

Hammermechanicman

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To do a starter voltage drop test there are 2 tests, the positive and the ground. To test the positve you connect the voltmeter to the terminal on the starter and the positive BATTERY TERMINAL not the bolt or the ring connector. Crank the starter and note the voltage. Should be less than .4 volt. To check the ground you connect the meter to the frame of the starter and the negative BATTERY TERMINAL. Then crank the starter and check the voltage. Should be less than .2 volt. What you are checking is the condition of the high current connections between the battery and the starter. The higher the voltage reading the worse the connection is. The difference of expected readings is because there is usually a slightly higher voltage reading because of current going through the starting relay or solenoid.
 

ljms

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Thank you. So if I understand you correctly, I have a good connection and no loss of voltage? I guess it is all black magic because I thought, and as did the starter repairman, that the voltage at the starter terminal should be just slightly less than the voltage across the battery terminals. You are saying that the way I am checking it,the higher the voltage at the starter terminal the worse the connections?? Doesn't make sense to me. When the starter key is turned, it should be sending voltage to the terminal to activate the starter. The higher the voltage, the better? So I thought. I guess I've always been under the impression that voltage was measured between positive and negative, amperage was measured inline the way you describe. Ok, again thanks.
LaVern
 

keakar

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The decompressor is not working
Take the rocker cover off remove the spark plug and do 2 full rotations of the engine.
watch the rockers.
You should see one of them open very slightly just before TDC on the compression stroke.
If this is not happeningand the valve lash is set correctly then the cam is shot and needs to be replaced.
However triple check you have adjusted the valves properly .
this ^^^^^^

they have a compression release lever on the cam and they are well known to break and fall off, confirm its not bumping open the intake valve (a tiny little extra bump is all it is) so watch carefully for it as you rotate the engine by hand

when its not working the engine will stop dry at the top of the compression stroke because the starters are not strong enough to overcome it

the cam kits with everything you need to fix it are like $75
 
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