Small Engine Question

[crokett]

My riding mower won't turn over when starting. It is acting like the battery but both Auto Zone and Batteries Plus say it is good. Batteries Plus actually tested it under load. It is not the solenoid, I took a jumper cable direct from battery to starter. It will start if I jump it off a car, or at least it did last fall. So, I think I have it down to either starter or valves need adjustment (compression is too high).

I may try jumping off a car again, that might eliminate the starter. Is there another way to test the starter? I was planning to change the spark plug. If I remove it to eliminate compression and then it does turn over, does that point to a valve problem? I am told the brand/type engine I have is prone to them.

 

[scsmith42]

David, check the connection where your ground wire attaches to either the engine or the chassis; this could be the problem.

 

[Vetteman9956]

+1 on the ground, Cable were it attaches to the frame clean any corrosion off. Drain old fuel out of carb and tank and clean the spark plug if it turns over but won't start. 80% of the time this will cure the problem in the spring.

 

[Travis Porter]

The battery may be good, but is it charged and is it rated for the correct number of amps for your riding mower?

Which reminds me, I have to fix my riding mower......

 

[Dudelive]

The battery may be good, but is it charged and is it rated for the correct number of amps for your riding mower?

Which reminds me, I have to fix my riding mower......

+1 Here for me also.

As stated battery may be good but may not have the capacity to start the mower due to being too small for the mower you have.

Like was mentioned clean the cables good....be sure to remove the ground cable and clean the mounting points where it fastens. Clean the metal and cable end both till shiny then reattach and coat with grease (wheel bearing) and it will not corrode again. At the battery end of both cables use a wire brush being careful about your eyes (Goggles work good) clean till it is shiny on the cable and also the battery.

When trying to start it exactly what happens? What sounds do you hear and when and from where is the sound.

What type of mower is this? This will really help

Give a post back, I might be in your area and give you a hand this weekend.

Just holler

Dudelive

 

[thrt15nc]

I had a similar problem with a John Deere riding mower. Bought a new battery, nothing. For the life of me I couldn't figure it out. Frustrated I sat down on the mower and was staring at it ready to take it back when ............realized that the last time I used it, I had shut the motor off with the blade engaged. Flipped the handle to dis-engage the blade, turned the key and thank goodness the noise of the engine drowned out my cussing. I guess it's some kind of safety feature on mine.

Tom

 

[Mark Anderson]

another vote for checking and cleaning all conections. do that before going further.

1) hook up jumpers from batery to batery, try to start. if this works you either have a bad conection at batery or your batery is not putting out enough amps.

2) with jumpers still hooked up go to the solonoid and determine witch cable come from the batery, with a small wire jump from this side to where the small wire attaches make sure the lawn mower is NOT in gear and that the blades are disengaged!! if this makes the lawn mower turn over the problem is in either the ignition switch or in the safty switches (blade engage, transmition in newtral, seat)

3) with a second set of jumpers or by useing two screw drivers that you aren't to fond of jump between the two large post on the solenoid (see red text above). if sparks fly, your screw drives are fried and the lawn mower turns over your problem is the solinoid.

i have never heard of valves neeeding adjusting, cant see how that would even be done. however there is a slim posibilty (very slim) that there is a feature to retard the spark. this is seen more on two cycle outboards for boats. if the spark is fireing too early it will seem as though there is too much compretion...like it will jerk the rope out of your hand. i have never seen this adjustment on a four cylender small engine though.

 

[McRabbet]

Isn't there also a safety contact that must be made when you sit in the seat? If that wire is broken, wouldn't that defeat the starting circuit?

 

[Mark Anderson]

yup and i just remembered there is one on the cluch pedal too

 

[skysharks]

I had the same problem with my Mower last year. Went thru the same thought process that you seemed to have gone thru.
Batteries, cables, connections, solenoids, starter, will start if I jumped it off, etc.
Then I checked the valves. They were just a bit too tight.
I found an excellent video of how to set them on you tube,( I'll look for the link).
Set them as instructed and poof, worked perfectly.

 

[NCPete]

darn, you guys have reminded me that I needed to look at my riding mower.... and it won't start. After checking wiring to the switch, the switch, and various other failure prone spots I have found in three years of selling Poulan branded machines, none of the common things were the failure point - continuity checked out on everything as it should.... absent this thread, I could have ignored the problem for another few weeks!:realmad:

 

[vdubnut62]

First, it is impossible for a valve adjustment to raise the compression too high. A valve is just that,
a valve, is is either on or off, it's not a regulator. If the valves lack proper clearance (ie too tight) you will lose compression and it will turn over but be hard to start, or not start at all. After you check the ground, if you happen to have a clamp on fluke meter, or the equivalent, check the cable where it hooks to the starter. Over about a hundred amps is bad. I you went from battery direct to the starter, you have bypassed the solenoid, not eliminated it as a potential problem.
If you have a Briggs and Stratton in particular my vote is for a bad starter. If you have cranked on it for a while, the brush holders will melt, if it's older the bushings will wear letting the armature rub against the magnets or the brushes will have worn away.
My opinion and a couple bucks might get you a cup of coffee!
Ron

 

[Travis Porter]

yup and i just remembered there is one on the cluch pedal too

I had a Husqvarna rider several years ago that I could not get to turn over. I replaced EVERY safety switch on it, and still couldn't get it to run. I sold it to a friend dirt cheap. Turned out the wire on the hour meter was loose and all of the safety wires and switches run through that.

 

[skysharks]

What I was refering to, but did not elborate on, is that on some mowers there is a compression release. Some are tied into the valve while others are tied into the canshaft.
I don't know how they work, but on mine if the valves aren't set right the motor does not turn over correctly.
It would by jumping it off.
Once I set the valves which is pretty darn easy, she turned over and has worked great since.
SO it's not that the valves increase compression, as it is the activation of the compression release during starting.
HTH

 

[crokett]

I fixed it yesterday. Fix was to take it to my mechanic. :gar-Bi After putting a bigger battery in and having the same problem, I jumped it off the car. Car got it to turn over and start but it ran extremely rich, lots of black smoke and gas was spewing out of the exhaust. At that point I quit and figured I had either carb issues, bad rings or both. My mechanic said he drained the oil and got more gas than oil out of it. He took the carb apart and cleaned it out. His theory is carb was stuck open a little so some gas got in the crank case. I flooded it with all my attempts to start it and made things worse.

 

[Gotcha6]

Have him install a fuel shutoff between the tank and the filter if you have one. When you finish mowing, turn the fuel off. When you are finished for the season, do the same while it's running and let the engine die. This will drain the carburetor for the winter. Use a fuel stabilizer additive in the fall.