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2019/10/15 08:28:24
Rick

John Deere Riding Mower Intermittent Start

I have a JD riding mower with an intermittent starting issue. I replaced the battery and starter and still have the same issue. I will start sometimes but not all the time. I have 12V to the starter. The starter will engage but will not turn the engine over. 
14 comments Leave a comment
AVB
Without knowing which engine you have I say that the OHV valves are needing adjusting. Note if a Kohler engine it may have hydraulic lifters which are self adjusting but there is also Kohler engine with regular valve train that require regular valve clearance adjustments. Every 50 - 100 hrs.
 
On OHV engine with adjustable valves, most have an ACR (automatic compression release) system which becomes disable if the valve clearance(s) are too great. This is mistaken by DYIers as a bad starter when it is just too compression at start up; therefore, they buy a new starter when it is not the problem.
 
Now there are other valve train problems that also can cause problem but valve clearances are a common problem.
 
2019/10/15 08:54:32
Rick
Thank you, it has a Briggs & Stratton OHV engine
2019/10/15 09:14:39
kshansen
Rick
Thank you, it has a Briggs & Stratton OHV engine


So as AVB says start with setting the valves! If you need spec's just post the model number of the motor and I'm sure someone will give them to you.
 
Hate to admit it that amany years ago I thought the riding mower we had at work had a bad starter and after installing a new on found problem was still there. Then I learned from some online site like this on how important valve settings were on these OHV engines. Quick resetting of valves and old starter worked like new.
 
And I spent 40+ years rebuilding large diesel engines!
2019/10/16 08:55:11
AVB
kshansen
And I spent 40+ years rebuilding large diesel engines!

Yes each basic engine design has there own set of rules. I have worked on basically 4 cycles until 10+ years ago when I started working on 2 cycles. A whole different set of test procedures involved but since my brother was working on the 4 cycles, and I basically was the parts procurement specialist and bookkeeper I had plenty of time to focus on learning the two cycle system.
 
I basically got a whole full size pickup truck load of old rejects from a local shop and proceeded to learn how to repair them. I start out taking all day to get one to work and now most are diagnose and repaired within a couple hours or less; depending how far I got to break them down. Even then I sold half of the repaired rejects which paid for the parts and some of the test tools.
 
My brother gave up after 1-1/2 yrs and wasted 6K as he was hardheaded about buying parts locally and going hog wild on unnecessary tools purchases. Only the 2 cycle side of business was supporting itself at the time. He left me in a mess as my name was on the business license and he had several uncompleted jobs which he already got prepaid for; therefore, I was responsible for the uncompleted repairs. When I closed the books he had only $650 in profit which I wrote him a check for and I rename the business and continue operating. I had kept the 2 cycle part separately from his operation so that profit wasn't part of the payment.
 
Several customers were mad about me completing the work since they knew I was the 2 cycle tech and was not my brother doing the work. Oh well that was 9 yrs ago and now the business is self supporting though it needs to a higher volume of business so it can support me. The business has currently a little over 5K in profit so far this year. Still a shoestring business but improving each year. It didn't help that I had to move my operations.
 
Now I am teaching myself ATV repairs. Boy are they compacted. So much that needs to come off just to get to a carburetor.
2019/10/16 09:52:01
Rick
Thanks All, I did a quick check last night and pulled the spark plugs out and it cranked every time.
2019/10/16 10:04:14
kshansen
Rick
Thanks All, I did a quick check last night and pulled the spark plugs out and it cranked every time.


So did you find the valves out of adjustment? Or something else that was the problem?
2019/10/16 14:19:54
AVB
What gather from the post he simply pull the plugs and tested. I hoping it is just a valve adjustment and not the 793880 camshaft ACR that is broken.
2019/10/16 15:12:01
Rick
I will pull the valve covers this weekend hopefully and check the valve clearance.
2019/10/16 16:20:20
kshansen
AVB
What gather from the post he simply pull the plugs and tested. I hoping it is just a valve adjustment and not the 793880 camshaft ACR that is broken.

 
I was thinking that what was being said but wanted a bit more detail.
Agree a valve adjustment is cheap and easy compared to a replaced camshaft!
 
2019/10/16 19:11:30
Rick
OK, adjusted the valves and still no start. Is there a way to find out if the ACR is broke without taking the engine apart?
2019/10/21 10:29:21
AVB
Yes. With the rocker cover off watch the rockers as you turn the engine through a couple revolutions. With both valves closed as you as near TDC one the rockers should move a little cracking open most likely the intake valve. This would be the ACR bump. If not present and valve are adjusted properly then the ACR on the camshaft is broken.
2019/10/21 10:55:43
Rick
I adjusted the valves again on Saturday. I adjusted the intake valves with the exhaust valves open and the exhaust valves with the intakes open. the engine cranked right over. will this harm anything adjusting them this way versus the TDC way?
2019/10/28 08:48:48
AVB
No, It is my preferred way of doing it as I have always done my valve adjustment this way. It just that Briggs thinks it faster their way.
2019/10/28 10:29:23
Rick
Great, thank you for the help.
2019/10/28 11:46:12

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