Small Engine Problems? Ask an Engine Mechanic for Answers ASAP
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You will need a multi meter to start checking where the voltage has dropped off from. Are you able to get a hold of one of these? Also how did you check the battery. 3 years is about the life expectancy of a battery especially in the cold
A multi meter is very easy to use. If you borrow one just ask who ever you are borrowing it from how to set it to DC voltage. Once you find one get back to me and we can walk through testing each spot to see where your break is.
One quick thing you can check is behind the dashboard. A lot of these mowers have fuses in the ignition system. The fuse is usually located between the ignition switch and the starter solenoid. If you find the starter and trace the large wiring going to it you will find the solenoid. It will have the starter wire hooked to one side, and the positive battery cable hooked to the other side. The small wire in the middle of it runs up to the ignition. This is where you will find the fuse if you have one
John W here again with the Sears riding mower. No luck getting a meter so far.
I have looked at back of instrument panel. From left to right, I found 1) wiring cluster going into starter switch, 2) mowing deck lever with another cluster of wires, 3) steering column, 4) throttle cable, and 5) wires to DC Amperes guage. Nothing resembling a fuse was found.
The wire from starter switch goes to a grounding post. Another cable from there goes to the starter (looks like a 1# XXXXX). A couple of long screws appear to go through the starter from bottom to a mounting plate on the top side. Does starter need to be removed to check? Removal looks difficult for the screw nearest the engine - virtually no manueuvering room for needle nosed locking pliers, which is what I have to use.
You may not have a fuse, most do but there are a lot that don;t use one.
Do not remove the long screws that go through the starter, that will only take it apart and not remove it.
Can you get me the model number off your mower and the model number off your engine please, then I can see what you are looking at..
Engine: Briggs & Stratton- Family YBSXS.501VP
Hope this helps.
I took at your mower and you do have a fuse. If you follow the wires from the lights they will go into a harness. Off this harness the fuse should branch off. Here is a copy of your electrical diagram, you will see the fuse marked 26. I am also including a link to the breakdown with the parts listed with there names and part numbers
Link to breakdown
Found it and pulled it - the arced metal filament under plastic shroud between the prongs appears intact. Since it's only $2 or so, do you recommend replacing it?
Absolutely replace it and see if that fixes your problem. The prongs will be intact, but if the filament is arced then it has gone bad. You should be able to buy a package of these for $2 at any auto store. This is just a normal 20amp auto fuse
I'll get it tomorrow and let you know results. We have warm weather here all week, so may need to start mowing in places by the weekend.
Thanks and good night for now.
Another day - another mystery.
I took the fuse to a parts store to get a replacement and was told that there didn't appear to be anything wrong with the fuse I presented. The fuses I looked at had a somewhat differently formed filament between the posts. The arced filament in the fuse I pulled from the mower looks die cut, not melted.
Since you stated that your battery was good I scratched that off the list. Yes you can jump the tractor off your car. If your battery is good then you should not get much of a result, but since it is free and an easy check you may as well try it. Make sure all the cables are hooked up correctly.
I did try the jump start a few minutes ago. You're right - nothing doing. I'll continue the hunt for a meter in the morning.
Had a busy day and have church responsibilities tonight - will try again for the meter tomorrrow.
I now have a multi meter, and I have printed out the parts diagram and list for reference. I should be ready to resume the engine diagnosis in 30 minutes or so - it's supper time around here.
Thats great! Here is your homework;First set the meter to volts DC. Attach or hold the black wire to the negative terminal of the battery. Hold the red terminal to the positive terminal of the battery . You should see that it reads 12 volts (or a little higher, normal is 11.5 to 13.5 volts DC)
Next take the black lead and hold it to the frame of the tractor. The frame is connected to the negative terminal and should give you the same reading as the battery test. You will notice that if you touch a painted surface you will not get a reading, but if you touch bare metal you will get the reading you are looking for. This is true for all the tests we are about to perform. All tested surfaced need to be clean of paint, rust, corrosion and dirt.
Now that you know how this works let's get to testing the system. The black lead will always go to a good clean ground in all these tests.
Test one - follow the positive battery cable to the starter solenoid (#43 it looks upside down in the picture) and test for voltage. You should have 12 volts
Test two - there is another large stud with a large wire on the solenoid, this goes to the starter. For this test you need a helper. With your helper sitting on the mower, clutch in and blades off have them hold the key in the start position and check for voltage at the starter side of the solenoid, you should have 12 volts
Depending on what you find we will continue from there. I am including a picture of a typical starter solenoid for you to aid in finding it easier.
Thanks! I'm refueled, and have unpacked a new multi-meter. Forgive me for another novice's question. There are no instructions on package about plugging in the cords into the meter. There are three ports-
First port is marked DC 10A and circled in red;
Second port is marked COM and circled in black;
Third is marked BAT and circled again in red.
Combination of #1 & 2 is marked 10A/15 sec max each 15 min - unfused
Combination of 2 & 3 is marked 315mA fused CAT II 600v.
Please advise on correct ports to use.
Sorry for the late answer, had to clean the bathroom.
You will want to plug the black lead into the common port, this is your ground lead.
The Red lead can go in either depending on how you are using it. I believe that you will want to use the Bat port.
We are not measuring amps, so do not be concerned about the fuse unfused.
Double check that you are getting 12 volts at the lead when you test the battery
No problem, make sure the meter is set to V for volts and is in the DC range. There is also an AC range for voltage that will give you nothing. Set it to 20 Volts DC, the symbol should be a V with a straight not curved line after it
DCV 20 with the red lead in the BAt hole
See if this helps, scroll down a bit until you see the picture of the meter. Thats where they talk about testing DC volts
Using a multimeter
Thanks again, but still stumped. I had a 9V battery nearby, so switched the meter to the 9V setting but still got no reading from that battery. Back to the store I go...
I did bookmark the how-to article on the meter for future reference.
Temperature here was in the mid 70s today, and the grass is growing! Hang in there, spring is coming.
Alright let me know when you figure this out. I will be away for the weekend, but will try to check in to see how this is going.
Mid 70's! I am jealous, we hit 40 today, I am ready for spring!
Saturday evening at this writing. I got back to the parts store yesterday and got further help to get the meter to read. I wish they had some instructions for first time users on the package. Following are readings:
Pos cable, battery to solenoid: 12.41
Solenoid to starter cable: 0 - tested twice per your instructions.
Hopefully we're getting somewhere now. Thanks for your patience while I learn.
Good to hear. Now we need to see if your solenoid has gone bad or if you are not getting juice to the solenoid. There should be a third wire that is much smaller then the two main wires going to your solenoid. Using the same setup as before (seated on the tractor, PTO off clutch/brake depressed and the key switch turned to the on position)
test for voltage at this little wire. You should have 12 volts here also
Won't have time to get back to this effort today, but will tomorrow evening. I'll let you know then.
I found two smaller wires that are connected with clamp fasteners. A single white wire to starter and a pair of blacks to ignition. O readings on both. I checked the battery again to make sure meter was reading - it's down to 11.8.
Hmm the wire going to the starter is a little odd. The wires going to the ignition concern me. At least one of those wires should have 12 volts when you are seated, clutch in and key turned all the way to start. This is what activates the solenoid.
Lets Check the switches that stop power going from the start witch to the solenoid. There should be three of them. The one that normally goes bad is located under your seat. It is pressed in to make it work, do not bother testing this for power, it is simply a ground that shuts everything down. You want to check and make sure it is connected and that the plunger is being pushed in. If everything looks good then go ahead and disconnect it, then try to start the mower (your clutch will still have to be in and the PTO will have to be off) If that fails use a paper clip of a short piece of wire and pug them into the two slots so they act as a jumper.
Let me know what you find and we will move onto the other two switches.
I'll try to check this tomorrow and let you know. My evenings are booked until Thursday this week.
I checked the shut-off switch and did the paper clip bypass - nothing.
Would it be helpful to you if I sent you a photo of the solenoid and wiring? I'll check my email again around 6 PM central time - be away until then.
A photo of the solenoid and wiring may be helpful. They are all relatively the same but you never know, it can't hurt to see what we are looking at.
Since the seat switch checks out lets try the other two switches one at a time. Both will follow the same procedure as the seat switch. The first is the clutch switch. You will most likely have to lay on the ground and really get under the mower to find this one. The other is the PTO switch (if you have an electric PTO please disregard this) This should be located behind the dashboard. Both are ,marked number 16 on the diagram I provided earlier.
Here it is again just in case
I skipped out on going to this evening's meeting to try to get a little farther along on this effort. I took a couple of pictures, but couldn't get them to compress sufficiently to fit into this thread.
The closest thing I could find to #16 on the wiring diagram is a 6-pronged pull apart connection with two of the ports apparently inactive. The snake from under the seat feeds into the connector. From there a pair each of red and black wires goes out - the red to the top of the starter; the black ones into the front of the motor somewhere. If this is the right place, I don't know where to apply meter prongs.
We are not looking for voltage anymore, these switches act as grounds that stop your engine from starting. We need to find the two switches that tell the engine that the Blades are in the off position and the clutch is depressed (the blade switch is behind the dash, just follow the engagement lever, this one is tricky to find. The lever actuates the switch) the clutch pedal does the same. Follow the clutch lever and it's linkage until you see the switch it activates, then test both like you did for the seat switch
Wednesday AM - I did push down on the blade switch plunger. Motor did get voltage to crank but apparently not enough to start. Battery still tests at around 11.7 volts. I tried to trace the clutch linkage but could find no switch. I may have time to try one more round around 6 PM central before church this evening. One other thing - you lost me on the PTO abbreviation- is that the blade switch?
Horray!!!! you found your problem!
The blade switch plunger is not being pushed in far enough with the lever that actuates the blade, so the engine thinks your blades are on when in fact they are not. 11.7 volts is good, but it is actually amperage that pushes the engine over when started.
Here is an easy way to check this and get your engine started. Depress your clutch and lock it in place with the parking brake lever. Set up your truck the way you did before to jump start it. The only thing we are going to do differently is to have you hold the plunger for the blades when you start it. This should give you the extra push the engine needs.
Once started the only way for you to keep it running is to remove the jumpers and sit on the seat. You are going to have to find out why that lever is not pushing on the plunger to get your engine running.
PTO = Power take off, this is what ever attachment that the engine is running besides the tractor, so yes in your case it is the blades
Thanks for the encouragement - might need some more, though. I put the cables on the mower for about 20 minutes, but got only a moan and a half-a-turn, then nothing more. Battery is up to 12.32 volts after the jump.
That's all the time I have for this evening - time to get ready for church. I can't skip this meeting - I'm the Bible teacher.
I'll check the mail again when I get in.
When you try jumping the tractor, leave the truck running, there is no need to try to charge the battery. With it running you should have it start. Make sure the terminals on the jumper cables are clean and making good contact battery. You may want to try placing the negative cable onto a good clean non painted metal part of the engine, this way you know you are getting a good ground to the starter and not having to pass through the battery and all the wiring.
A moan and a half a turn is much further then we were 2 weeks ago! We'll get there
Wednesday evening - back after church.
The truck motor was running all the time I was jumping off the tractor. I tried it again moments ago, but nothing happened, even with black cable on neutral ground underneath. I then disconnected the cables and sat down on the mower. I was able to reach around and push down the plunger while turning the key with clutch in and got another moan and half-a-turn but no more.
I'll pursue further instructions tomorrow.
OK we know the blade switch is the culprit for the engine not turning at all.
Lets troubleshoot the rest of the engine. Go ahead and remove the spark plug, tape up the spark plug wire end with tape so that it does not spark by mistake. Now with the plunger for the blades pushed in try to turn the engine over and see what it does. It should turn the engine over very easily. Pay attention to the spark plug hole and see if anything like gas or oil squirts out of it (the main reason for taping the spark plug wire up, we don;t want to create an explosion outside of the engine) If you still get the same results let's isolate the battery. On your starter solenoid the first post that we tested (coming from the battery) hook your positive cable from your jumper wires up to this post and the negative to a ground on the engine (spark plug back in) and see what happens. We are getting closer!
Back on the lawn mower this evening. I removed the spark plug and taped the wire. The motor did turn over easily as you said. I didn't have an assistant handy this time, so couldn't look into spark plug hole- too tight a spot to get my head into anyway without taking the hood off the hinges. I am happy to report there was no explosion! FYI: while I have the plug out, I cleaned it with carb cleaner - threads were quite dirty and black, but tip was white.
No explosions are a good thing! You really did not have to look directly into the spark plug hole, if anything like oil or gas had come out then you would have seen it hit the hood. If your plug was as dirty as you say you should probably replace it.
I'd like to try the jumper cables hooked up with the positive going to the battery side of the solenoid and the negative cable going to an engine ground. If this does not work then I think we are going to get more involved and we'll try to set your valves. It sounds like the decompression part of your engine (used for starting) is sticking not allowing the starter to completely turn the engine over. When this happens you will try to crank the engine and it will turn over to a point where it just stops and will not push the engine any further. I can walk you through this as it is not very hard to do, but you will need a set of feeler gauges (they are just thin strips of metal marked in various thickness's)
Plug is back in with wire connected. Just a click and slight turn this time.
Ok it looks like we are going to have to adjust your valves, you are going to need a feeler gauge, and some simple hand tools (ratchet, and maybe an allen wrench) to remove the cover and adjust them. Do you have these items?
For my reference your engine model is a 31C707-0230-E1
I do not have feeler guages. I called my brother-in-law's number - still no answer - so I guess I'll buy them with the new spark plug tomorrow. I do ahve a couple of sets of Allen wrenches. Will a socket or crescent wrench work in place of the ratchet?
Will do - that looks like as far as we can get this evening.
The bunches of clover are nearly a foot high in places now.
No problem, I want to see this running as much as you do.
For your information, I try to always answer even if there is no useful information just to clear my board, otherwise I may miss something important from you thinking it was a previous answer
By the time we are done, you are going to be able to help all your friends and parishioners out with their tractors!. No worries on the patience I am into this as much as you are
Friday evening -
I have new spark plug and set of feeler guages, and ready to resume on the mower repair project. Supper will work into the mix somewhere, but otherwise I will try to follow up and respond to your directives as quickly as possible.
Alright, here we go!
You can leave the spark plug out for the time being. Find the Overhead valve cover and remove it. There will be four bolts holding it on, one at each corner and the cover should be marked OHV. It will be very close to where the spark plug is. Once that is removed I want you to turn the engine over by hand (not with the starter) Watch the valves, as you turn it they will open and close (down is open up is closed). We want them both in the closed position. When you get to that point insert a pencil in the spark plug hole (it should not go in very far) Turn the engine slowly and watch the pencil. We want the pencil to be as far out of the hole as possible, go too far and it will start to go back into the hole.
Once you have this done both rocker arms (the things that push on the springs) should be a little loose.
Let me know when you get there and I will give you the next few steps
I've been refueled, and have performed the steps requested. Both rocker arms look parallel to the front cover of engine at this point.
Sorry it took me a few minutes.
Good they should be slightly loose at this point. Using your pencil insert it into the spark plug hole and mark where it sits. Now measure one quarter of an inch up the pencil and make another mark. Now insert the pencil and turn the engine in the same way it normally turns until the 2nd mark on your pencil is where the first one used to be. Now we are ready to adjust the valves. You will need your .005 feeler guage for this. Where we are feeling with these is between the rocker arm and the nub of the valve that is coming out of the spring. Your feeler should slide between the two with slight resistance, not binding, but not loose. You will need to check this several times to make sure you get it right. The allen head screw in the center of the nut that holds the rocker arm in is a locking screw, just back it out a few turns. Then adjust the valve with the larger nut in the center of the rocker arm. Once you are satisfied with it then lock the allen screw back down while holding the nut very still
Double check everything one more time and then reassemble the cover and insert the plug and start that baby up!
I got down to the rocker arms OK. I was only able to get the feeler guage into one side of valve nub (3 o clock position looking down from above). The rest of the way around feels too tight to slide the guage in.
My allen wrenches wouldn't fit the locking nuts - looks more like a star nut from what I can see. A locking wrench loosened both nuts. The bottom arm was looser than the top. I have them both snug now, but can't get the feeler guage to slide in all the way around, as I mentioned.
I broke the gasket in one place getting the cover off. Is a new replacement necessary before I put the covers back on?
You have an engine that does not use allen wrenches on that screw, these star shaped screws are called Torx head screws. You will need to get a hold of a torx screwdriver set. (looks like your tool collection is growing!) That screw should be either a T20, T25, or T27 sized Torx head. This is the only way to adjust them correctly. With one being too tight that may be our problem.
As far as the gasket goes you can reuse it for testing purposes, it will leak oil, but not enough to worry about before the engine is running. Once it is up and running you will want to replace it. The part number for that gasket is Briggs and Stratton part # XXXXX Any good small engine shop should be able to get it for you.
I'll go shopping for the screw driver set and gasket tomorrow. I want to clean this area with carb cleaner when I have daylight. It's black and grimy on the outside, but the metal cover over the rocker arms was clean as new on the inside.
Looks like we're through for this evening.
Hope to have an update for you when you get back. I am gratified that so far I've spent more on tools than parts!
Take care! Sounds like you're in that part of the country where they pronounce it "kayah." Around here they say "keer."
Haha, yes I am in southern NH, a little too close to Mass
I'll be back in touch with you tomorrow. Take care Sir.
Hope everything went well going to RI and back. In years past, I have traveled the east coast from Orlando to Philadelphia. I have visited NH ever so briefly, crossing over the Connecticut River from Brattleboro, Vermont during one trip so I could say I've been to New Hampshire. Only RI and Maine remain among my unvisited states east of the Mississippi River. Other than the spectacular fall colors, my other lasting memory of New England is all the toll bridges!
Now back to the mower. I got the valves adjusted, and have new spark plug and air filter installed. I called a man in our church who tinkers with cars and appliances to check my work before I got the covers put back on. After inspection and re-assembly, all I got was a buzz and a clicking noise below the carburetor, even with a jump from a vehicle. He did some other checking for spark, or lack thereof, and came to the conclusion that the starter is bad. He helped me get it removed, and pointed out to me the wear on the top of the teeth on the little fly wheel. He suspected that the wheel has not been making good contact with the engine's flywheel and suggested I take the starter to a rebuilder in town who has his confidence. I have never had any starting problems with the mower before it quit. The starter on my truck suddenly quit earlier this winter, but I was able to get it started again by tapping on the starter while my son turned the key. We live in the country, and that saved us a towing bill to get the vehicle to a shop in town. That trick didn't work on the mower, however.
Even though we still don't have a successful resolution, I want to give you fair compensation for all your time the last few weeks. I've learned a lot, and haven't been out a lot of expense. I'm trying to save money where we can to survive these days. We have a lot of medical expenses for my wife who is not in good health. I'm not familiar with this system other than clicking the "accept answer" button for a problem solved. Let me know what to do from here.
Long day today! I left at 7am and am now just getting home.
Did you bench test the starter? Meaning put the jumper cables right on it. Neg would go on the body (ground) and positive would go to the terminal. As soon as you touch the second cable the starter should jump right to life. These little starters do not usually get rebuilt with the exception of the starter gear up top that you spoke about.
I am not convinced that this is your problem, but it is worth having it checked out. A little wear on the teeth is not a big deal if the starter is turning the way it should be.
When you feel that you have been satisfied all you need to do is click the accept button. The deposit that you placed when you opened this question will then be released and I will be compensated.
It's been a long day for me this time, but a successful one.
I took the starter to the auto parts store where I visited previously. It tested bad for them. I then took it to the rebuilder's shop across town, where it tested good. Obviously more comprehensive testing that involved the testing and results you described. The technician took the starter apart, and reported that the brushes looked fine, and the worn teeth issue didn't amount to anything. He told me to bring the battery in for testing under load, which I did later in the day. The multi-meter showed it had been losing charge during all the testing, and was now completely dead. I got it traded in for a new one for $25 + tax. I had a funeral to attend this afternoon, and a family get-together this evening to celebrate my mother-in-law's 80th birthday. Between the two events, I had enough time to swing by the house to reconnect the starter and drop in the new battery. With the aid of a little starter fluid, the mower started and I took a celebratory spin around the yard to cut a couple of passes of clover. Two days of rain are predicted now, but the yard will get mowed by this weekend!
Many thanks again for your patient coaching and enabling me to save a big chunk of $$ to put on a $760+ dentist's bill for my wife to get a tooth capped- can't find a cheaper way to get that done!
God bless you as you dig out yet again while I mow.
John, I couldn't be happier to hear that you are up and running! Great job and it was a pleasure to work with you. Normally these questions go back and forth 2-3 times before a result is found. We hit 41! I am in no way complaining, I get a charge out of finding a result to a hard problem
Goos news on my end as well. No snow! All we got was rain on the coast and now the snow is melting!
If you ever need help again please do not hesitate to ask.
Return final greetings and appreciation. There is a local one-of-my-kind I met once who would be a good friend with whom to make acquaintance some time during your lifetime... Pastor David Howe in Hudson. We specialize in matters of the heart, soul and spirit!
Yours very truly,