Small Engines (Lawn Mowers, etc.): Scotts S2046H starting issue?, engine model type, weight oil

Question
QUESTION: I have a Scotts S2046H mower and the starter does not turn over the engine. If I remove a spark plug it will turn over. I have tested the battery, and tested the starter off engine. Battery is new and in great condition and the starter spins on the bench. I also hooked up a remote start switch and connected it to the starter on one end and the + side of the battery on the other end. The same thing happened, no start with both plugs in. I removed the valve covers and the rockers/valves move as they should. I am wondering if the starter is not up to the task of turning the engine with compression. I do not think it the issue is in the electrical system as the starter spins the engine with one or both plugs out. Any advice would be great before I buy a new starter.

Thanks,
Brad.

ANSWER: It is difficult to troubleshoot weak starters unless you have some special equipment.  A DC shunt will help check the current the starter is drawing while under load.

If you have a local electric motor shop near your location it would be worth calling them and checking to see how much they charge for checking the starter.  While I haven't found many bad starter I have taken a couple in to the local electric motor shop to have a few checked.

Send me the engine model, type and code number to see if your particular engine may be prone to other issues that would cause you problem.

Does your oil smell like gasoline and what weight oil are you using?  Will the starter turn the engine over if you rotate the engine by hand first?  Can you rotate the engine by hand?

Let me know.
Eric

---------- FOLLOW-UP ----------

QUESTION: Engine is a Brigs 20 horse 2 cylinder gas. Where do I find the engine code? The engine spins over by hand and I use 5W30 Mobile one with no fuel smell from the oil. I have had the starter checked and it is good. I went today and purchased a new starter to check and the same thing happened. It will start once in a while but still not very often.

I have pulled out the battery and putting it on a charger for reconditioning and then I will charge it to make sure it has enough amps. It tested good but I have the equipment so why not use it. I also installed a separate ground wire from the starter mount bolt to the negative on the battery. Just to see if the ground on the engine was dirty and not making a good ground contact. Nothing changed.

Thank you Eric for your time,
Brad.

ANSWER: The link below will help you locate the engine information:

http://engines.myfaqcenter.com/Answer.aspx?p_faqid=13

I have had weak battery cells cause problems like you described. Did the problem start suddenly or has the mower sat for a while?

It is possible to have a bad battery cable...had it happen once on an old mower.  

Below is a link describing how to check the voltage drop.  It's a good link but it may be eaiser and just as cheap the replace the positive battery cables.  

http://www.aa1car.com/library/voltage_drop_testing.htm

Check what you can and send me the engine information.  I want to see if there are any issues with the compression release on your engine.

Eric

---------- FOLLOW-UP ----------

QUESTION: I have over looked the easy stuff. I found out that my valves were out of adjustment. Too loose, so I reset the Clarence to .005 and she fires right up every time. The valves were staying closed to long causing to much compression and the starter did not have the torque to push past it. Now it is happy. Thank you Eric for the info.

Brad.

Answer
Keep an eye on the valves.  Once in a while some engine models will bend a push rod.  It's easy to check the push rods by rolling them on a piece of glass and see is they appear to wobble.  Straight push rods will not appear to wobble.  Of course, this is the "shade tree" check but it works well and is cheap and very quick as compared to buying V blocks and using a dial indicator.

Glad to hear you fixed the problem.  There are a few engine models suspectable to compression release problems, that's why I was looking for the engine model, type and code nubmer.  Don't worry about the compresseion release as it pretty rare they fail.

Eric