Hard To Start My Mower

[Pappy]

motors/electronics on a small engine are not designed to take the amperage of a car system. This is also true of motorcycles. If you have to boost your battery, use a charger set to 10 amps.

If there is power available where the mower is stored, invest in a Battery Tender Jr. It is a float charger that will shut off when the battery is charged and turn back on when it senses the voltage is to low.

[phi1l]

I'm not mowing yet. I am trying to get it fixed now so my FIL can mow it and do other stuff.

That gets a double "You Suck"

[Kristofor]

By the way, that first post-mow beer of the season went down mighty good!

Wait, you're South of the line... Aren't you guys supposed to be drinking the beer while you mow?

[crokett]

Ok so.... found out one of my problems was the charger I had wasn't. So got a spiffy new float charger that at least said the battery was charged after several hours of charging. Still won't turn the engine over, although it tries. It does work when the engine is warmed up. Manual for the mower specs 190 CCA, my battery says it is 243. Is it possible that I just need a battery with more oomph on a mower that is 5 years old?

Anyway, I will work through this and see what I can figure out. If I want to test the starter, is the ground connection normally through the case directly to the frame? I only see one lead on it. I will try running a jumper cable direct from + post on the battery to the starter and see what happens.

[RAFlorida]

David, the 243 cold crank amp (CCA),

should be enough. If you can check your battery posts for the voltage while trying to start will tell you the shape of your battery. It was mentioned that it should not be less than 10 volts. Yeah, the started is ground through the chasis. Hope this helps.

[crokett]

Figuring out how to test will be interesting. right now I am thinking about clipping a lead to the starter and then one to ground and hooking the tester to those since there is a safety switch on the seat and it has to be down to start the mower.

[crokett]

Ok, first thing is the battery is delivering 12.25V across the terminals. Next, put a jumper cable red lead on the starter, other lead clipped to my tester. one black lead onto battery terminal,. other clipped to my tester. I tried going directly to ground rather than battery terminal but couldn't find a good ground anywhere on the frame. During cranking it read 7.5<>8.3A. Next turned ignition to on, put red lead on the battery, other red lead to starter terminal and after the sparks, same thing, engine would barely turn over. I am thinking starter motor problem? Although since a car battery with more CCA starts it I am also thinking battery.

[Jcrawf]

I had the same type of problem with the Briggs and Stratton engine on my Snapper mower. Turned out to be a valve problem. The compression release is controlled by the valves, and if they aren't set properly the starter is trying to turn an engine that has too much compression for the starter to handle. The starter will turn the engine a quarter or half turn, but no more. Mine is an OHV engine. If yours is the same, chances are good you need to set the valves. Here's the resource I used to learn how to set the valves:

http://www.youtube.com/watch?v=NjzX-PUjKmo

Good luck with it,
Jack

[crokett]

Thanks I will look into it. I believe the engine is an OHV engine, I do know it is a B&S. That is consistent with the symptoms - the starter will turn the motor, but just barely and then not very far. It would explain why jumping off the car battery works. Watching that video, he obviously knows what he is doing. When I do this I am really going to be fumbling. For example, what is a safe way to turn the engine over to move the valves? Engage the blades and turn them? Oh, and I will pull the spark plug when I do this, it needs to be changed anyway.

[Jcrawf]

My engine has a metal "screen" on top of it that rotates when the engine is running. I used a piece of 1X2X14 scrap with a couple of wood screws driven partially through it, at about 6" apart. The points of the screws engage holes in the screen. This setup allows the engine to be rotated easily.

To check for top dead center on the piston, I used a length of dowel (a pencil will do) through the spark plug hole.

Jack

[billwmeyer]

I don't think it is the battery. As I stated earlier, I have had this happen twice. One was valves, and the other was starter. My mower with the valve problem did not stay set and would vibrate out of adjustment. I even used locktite. I had no time to mess with it and bought a used mower for last year. I hope to get time to replace some parts this year on it.

If it was me I would remove the starter and have it tested. Good luck.

Bill

[crokett]

Bill I am gonna do that next. Auto Zone says the battery is good. I think it is either valves or starter. The Auto Zone guy said if it was valves I should get back firing. I occasionally do but I think the starter is easier to get to so will go for that next. I also think I will call MTD tomorrow and see what their tech support says.

[Jcrawf]

If the engine turns up nicely with the spark plug removed and the key turned to the start position, that pretty well eliminates the battery and starter as problems.
Jack

[crokett]

If the engine turns up nicely with the spark plug removed and the key turned to the start position, that pretty well eliminates the battery and starter as problems.
Jack

Do you mean pull the spark plug and try to start it and it should go to TDC? If it does then it is a valve problem? I am going to change the plug anyway.

[pelligrini]

Pulling the plug will let the pistons move fairly freely, without the compression. If it cranks well it might mean there is valve problem. It could also mean that the starter is too weak too.

I used to pull the plugs on my Camaro when doing valve tappet clearances on my old engine that had a solid lifter cam. The engine would turn pretty easily with the plugs pulled.

Have you changed the oil recently? I put a heavier viscosity oil in my mower than what Briggs & stratton recommended because I had it on hand at the house. It was much harder to pull start.