John Deere D100 Starting Issue

[andrewe1121]

Hey guys,

I have a special needs guy in my neighborhood that cuts grass for a living. He has a John Deere D100 with the John Deere branded 19hp engine. He purchased it from a guy that buys old mowers and fixes them up for resale. It appears there were some modifications made to the mower, which appears to include the removal of some parts (that will be part of another forum question if I can’t figure out the cutting deck).

Recently the mower started having cranking issues. He was using a jump pack to crank the mower each time, and was told by someone that the solenoid was bad. A new solenoid was purchased and installed, and a new battery was also installed. However, the problem persists. This is when I came into the picture and started helping him.
I tested the battery with a multimeter, which shows the battery at around 11.5 volts. I removed the starter, and used jumper cables running from the mower battery to bench test it. I got no movement from the starter when I did this. I then attached his jump pack to the battery, along with the jumper cables, and ran the bench test again. The starter functioned at this point. I’m not a mechanic, so I’m not sure if the starter is functioning properly, or at a reduced rate.
Does anyone have any suggestions for what I should do next to further diagnose the problem?

Thanks!

-Andy

 

[StarTech]

Being a Briggs 310000 series engine first check valve clearances and the intake valve rocker is being bumped as the approaches TDC compression stroke. IF not there after valve adjustment then the ACR on the camshaft is broken and the camshaft would need replacing.

 

[andrewe1121]

Being a Briggs 310000 series engine first check valve clearances and the intake valve rocker is being bumped as the approaches TDC compression stroke. IF not there after valve adjustment then the ACR on the camshaft is broken and the camshaft would need replacing.

Thanks for the response. The engine cranks fine with the jump pack attached to the battery. Do you know of any web links for checking and adjusting valve clearance, or should I buy a repair manual for the engine? He doesn’t have enough money to pay a shop, so I’m trying to fix it at my house.

 

[Rivets]

With some searching you can find a free manual online in pdf form.

 

[hlw49]

You need to test the battery with a load tester take it to a parts house and have them do a load test on it. 11.5 volts is not a charged battery. Checked all the electrical connections from the battery to the solenoid and starter also check the ground cable connections. When you get it running again check the voltage at the battery with your multimeter and you should get over 12.75 volts. If not you have a charging system problem.

 

[bertsmobile1]

Measure the voltage from the starter + to ground with the engine cranking ( or trying to ) with the battery alone and with the battery + jump pack.
Chances are he has a bad connection on one of the battery straps .

I like to bypass the mowers battery cables one at a time using jumpers from the battery to a good ground & from the battery to the starter & starter solenoid .

If it cranks fine when jumped & dosn't without the jumpers ( booster to some ) then the battery cables are the problem.
JD likes to bolt the ground to one of the engine bolts and the nut has a habit of coming loose so you do not get a good enough contact to crank.
The battery pack could just be supplying enough power to overcome the bad connections.

 

[StarTech]

Yes the battery could be weak IE dropped a single cell. Being only at 11.5v is not a complete cell failure more like it is just low on charge from attempting to crank the engine. The starter pulls over 80 amps when the engine's valves are adjusted properly but pulls a lot more when they are not. This can pull down an used battery rather quickly.

And the Briggs single cylinder OHV are bad about needing the valves adjusted on a regular basis. It is also common that to have the ACR to fail. This is something that be checked on these engines whenever they come in into my shop for starting problems. Also a leak down test is advised as the 310000/330000 are prone to blowing the head gasket between the cylinder and the push rod galley. And this is best done while the rocker rocker is off so you can listen at the push rod galley for this problem. IF the gasket is as describe above the air escaping will louder at the galley vs at the oil fill tube. I seen many of these engines destroyed due to lost of oil caused by this.

I know this is lot to understand and do for a non mechanic but it things like this needs to be checked if nothing else to be done as preventative maintenance.

Here is the service manual for this engine that I found online.

Briggs Single Cylinder OHV Service Manual

 

[andrewe1121]

Yes the battery could be weak IE dropped a single cell. Being only at 11.5v is not a complete cell failure more like it is just low on charge from attempting to crank the engine. The starter pulls over 80 amps when the engine's valves are adjusted properly but pulls a lot more when they are not. This can pull down an used battery rather quickly.

And the Briggs single cylinder OHV are bad about needing the valves adjusted on a regular basis. It is also common that to have the ACR to fail. This is something that be checked on these engines whenever they come in into my shop for starting problems. Also a leak down test is advised as the 310000/330000 are prone to blowing the head gasket between the cylinder and the push rod galley. And this is best done while the rocker rocker is off so you can listen at the push rod galley for this problem. IF the gasket is as describe above the air escaping will louder at the galley vs at the oil fill tube. I seen many of these engines destroyed due to lost of oil caused by this.

I know this is lot to understand and do for a non mechanic but it things like this needs to be checked if nothing else to be done as preventative maintenance.

Here is the service manual for this engine that I found online.

Briggs Single Cylinder OHV Service Manual

Wow. Thanks for all the info and that service manual. I’m really starting to think it’s either the valves or the ACR like you suggested. I was baffled by the electrical issue, because all connections are good, it has a new solenoid and battery, and the starter almost jumped off the ground when I bench tested it. Again, I’m not a mechanic, so it never crossed my mind that an internal engine issue could be causing the problem because it appears to run fine once it’s cranked. Y’all have given me enough info now that I think we can get the issue resolved. Thanks!

 

[MyGrassHasCrabs]

OP - I had the same symptoms - my Scott's JD would turnover but not start unless I connected a jump battery. I took the valve cover off and adjusted the valves - you can find youtube videos on how to do this - it's not hard but you have to be precise and have a torx screwdriver bit that fits. Once I adjusted the intake and exhaust valves it started right up, no jumper cables, just battery. Good luck!

 

[StarTech]

Should be a T20, Torque to 75 in/lbs.