Outdoor Power Equipment and Small Engines - Craftsman LT2000 - Briggs 18 HP fires once and dies

I have a Craftsman LT2000 with a Briggs & Stratton 18 HP engine (model 31H777). While mowing the other day, I got bogged down in the mud and the engine died. Since then, I have been unable to get the mower to start.

It turns over when I turn the key in the ignition, but doesn't fire or only fires once. I tried pouring fuel directly into the carb and it fires but quickly dies. I replaced the fuel filter and dismantled and cleaned the carb, but still get the same result. The battery is good and I get 12 volts at the line connected to the fuel solenoid? under the carb bowl.

Hope someone has some thoughts on a fix. Thanks in advance.

Scott

Scott,

Can you put your fingers on the fuel solenoid and feel/hear it click when you turn the key switch on and off ?

Could be a piece of trash hanging it closed.....It could be bench tested out of the carb with jumper leads to assure it's fully opening/retracting.

Scott,

Can you put your fingers on the fuel solenoid and feel/hear it click when you turn the key switch on and off ?

Could be a piece of trash hanging it closed.....It could be bench tested out of the carb with jumper leads to assure it's fully opening/retracting.

I don't notice any clicking over the vibration of the engine spinning.

Well, I replaced the fuel solenoid and got what seems to be pretty weird results. When I initially replaced the solenoid, I used the bowl that was already on there, I tried it and it fired and ran for about a minute. I turned it off and went to put away my tools and noticed a leak. When attaching the solenoid, I thought the hole where you attach the solenoid might have been stripping. So I run get a new bowl, get it attached to the new solenoid and the carb, and when I try it, I get the same results as I was getting before replacing the solenoid. It turns over but won't fire (or maybe fires one time).

Any ideas?

Thanks,
Scott

One other note. In trying to think back about what might have been different between installing the new solenoid with the old bowl and again with the new one, I remembered that I dropped it when taking it off of the old bowl. How tough are these things? Could I have messed up the windings or something when I dropped it? Is there a way to test to see if it is working?

Scott,

I posted in my first reply this solenoid can be tested using jumper wires to a battery to see if it's retracting.

Are you sure you got the main jet good and clean ?

It sounds like the problem may not be fuel related,
although it seems to be the focus.

If you pour a dribble of fuel in the carb throat, it should run for several seconds before dying, and one could keep it running by dribbling fuel slowly, if your problem is fuel
related.

If you cannot keep it running that way, then you need to look elsewhere, like ignition, or valves

Firing once, makes me think something else.

Fish

I left the fuel solenoid connected to the wires and removed it from the bowl. I then hit the ignition to see if it retracted and I didn't notice any movement.

The mower didn't turn over very easily, so I thought the battery might be failing. I tested the voltage and got 11.9V. I also tried to test the voltage at the terminal that connects to the fuel solenoid and couldn't get much of anything (maybe 1V). Not sure if I was getting great connection. Should I be getting 12V there?

I also tested the voltage at the starter and wasn't getting much voltage there either.

Put your test meter back on the battery then hit the start position watching voltage drop, You could have a bad/dirty battery/frame ground connection or a blown strap in the battery.


Good Luck

I left the fuel solenoid connected to the wires and removed it from the bowl. I then hit the ignition to see if it retracted and I didn't notice any movement.

The mower didn't turn over very easily, so I thought the battery might be failing. I tested the voltage and got 11.9V. I also tried to test the voltage at the terminal that connects to the fuel solenoid and couldn't get much of anything (maybe 1V). Not sure if I was getting great connection. Should I be getting 12V there?

I also tested the voltage at the starter and wasn't getting much voltage there either.

Yes, there should be 12 volts at the solenoid. There should be 12 volts at the starter cable with the key turned to start with the cable disconnected from the starter. If you measure it with the cable connected and the engine turning, then it will be much less.

"The mower didn't turn over very easily,"

A common cause of this with 31 series 18 hp B&S engines is that they need the valves adjusted.

Walt Conner

When I tested the voltage at the battery when trying to start the mower, the voltage dropped to between 3V and 6V.

Can I try to jump start the mower off of my car battery? I saw a comment in another discussion saying not to jump it off your car battery without disconnecting something?

You can jump it with the car battery. It does sound like you might need to adjust the valves...among other things. Did you measure voltage at the starter cable like I mentioned?

I get 12V at the battery and 11.3 at the starter cable with it disconnected from the starter.

After reconnecting the cable to the starter, it won't even turn over. I get about half a turn.

So have you adjusted the valves?

Which valves should I adjust? and what's the procedure fro doing that?

Thx,
Scott

Check the battery voltage with the starter connected & trying to crank the engine. this is kinda like a load test on the battery under operating conditions. Sometimes a battery will show 12 volts when sitting, but under load It may not have the power you need.. Roger

You need to take a step back, and take a moment.

Look at the "cranking" problem first. Cure that, and all of the
others will likely be resolved as well.
A good battery will show at least 12.5- 12.7, it should read about the same everywhere else when the key is turned.
Look at the ground cable, and the positive battery cable.
You may just need a new battery, but a bad ground is a good bet.
Cure the "cranking" problem, and i am willing to bet the
others will be solved as well. Keep us posted with good
details.

Fish

To make sure that the valve adjust is not an issue, leave the spark plugs out until you get it to crank good.

Fish

I tried jump starting off of my car battery. I was able to get it to crank but it wouldn't fire. I poured a little gas in the carb and it fired once but then died.

hi everyone. new to the forum, but my question or problem is the same as this person, so I didn't want to start a new thread. I am a mechanical novice. I don't have a ton of experience with engines. Here is what I know. If I charge the battery, my 18.5 HP briggs and stratton (same craftsman tractor - LT2000) will start and run. However, it REALLY struggles to start. If I pull the spark plug, it spins much more freely. I am completely stumped at what could be causing this problem. What could be making the tractor struggle to turn over? Sometimes it fires just once, but mostly it just struggles to turn over.

Billy, Measure the voltage @ the battery when cranking from a clean positive post to a clean negative post on your freshly charged battery (on the posts, not the clamps), (I know,hard to do, make up some small jumper cables), then measure the voltage @ the starter when cranking & post the figures. This will tell us about the condition of the positive side crank circuit & the battery....Roger

Billy, Measure the voltage @ the battery when cranking from a clean positive post to a clean negative post on your freshly charged battery (on the posts, not the clamps), (I know,hard to do, make up some small jumper cables), then measure the voltage @ the starter when cranking & post the figures. This will tell us about the condition of the positive side crank circuit & the battery....Roger
I will have to get back to you on this as I dont even have the tools to do it. If it helps, the battery is brand new. What are you looking for?

The compression release is dependent on proper valve adjustment. If the valves are not properly set (have you set them in the past 2 years? If not, they need adjusting), then the compression release will not function properly and the engine will turn a little and stop on the comression stroke, or struggle through the compression stroke.

Put the engine 1/4 turn past TDC on the compression storke, pull the valve cover, set both valve clearances to .005, and go mow some grass.

The compression release is dependent on proper valve adjustment. If the valves are not properly set (have you set them in the past 2 years? If not, they need adjusting), then the compression release will not function properly and the engine will turn a little and stop on the comression stroke, or struggle through the compression stroke.

Put the engine 1/4 turn past TDC on the compression storke, pull the valve cover, set both valve clearances to .005, and go mow some grass.

sounds simple enough. is there a diagram of this procedure somewhere on the net?

http://faqs.custhelp.com/cgi-bin/faqs.cfg/php/enduser/std_adp.php?p_faqid=3441&p_created=1101860144

my valves are fine. it's got to be electrical. :blah:

Billy, Measure the voltage @ the battery when cranking from a clean positive post to a clean negative post on your freshly charged battery (on the posts, not the clamps), (I know,hard to do, make up some small jumper cables), then measure the voltage @ the starter when cranking & post the figures. This will tell us about the condition of the positive side crank circuit & the battery....Roger

I will look into this roger. I will need a friend of mine to give me a hand this weekend with it.

PS - there was some oil under the valve cover. is that major cause for concern?

So you're saying you checked the vlave clearances and you've adjsuted them in the past 2 years? Yet it spins fine with the plug out, but not in?

So you're saying you checked the vlave clearances and you've adjsuted them in the past 2 years? Yet it spins fine with the plug out, but not in?

I just adjusted them.

Something seems to be draining the battery. Now, it still struggles to spin a bit even with the battery fully charged, but I am thinking the starter or the ignition switch are draining the battery too... maybe the valves were part of the problem, but there definitely seems to be an electrical issue as well.

ok. I got it to start good, with no hesitation, but then after it ran and got warm, it fought me to start again after I stopped it. Then, if I wait a bit, it turns over with hesitation, but it turns enough to start. I adjusted both valves to .005 and it runs better, but still has a hard time starting.

I replaced the solenoid and that did nothing. It must be the starter.

Okay. For all you curious minds, it wasnt the starter. It was the armiture AND the flywheel. Both needed to be sanded real good to get a better magnetic connection. I got it running really good now. I readjusted the valves to make absolutely sure I had them right, and now she purrs like a kitten.

Thanks for everyone's help.

Glad you got it, and thanks for the update. Sounds like your valves just needed adjsutment. The armature and flywheel rust won't make it hard to crank.

Glad you got it, and thanks for the update. Sounds like your valves just needed adjsutment. The armature and flywheel rust won't make it hard to crank.

Hey cheese, I am not going to get too argumentative over it because I really appreciate your help, but the tractor wouldn't turn over consistently until we sanded off the rust. Once we got it to start, we heard a tapping sound which told us that our first attempt at adjusting the valves wasn't quote right. Turned out the exhaust valve was a hair loose.

All I want people to know is, if you wash your tractor's engine, use air, not water. If it wont turn over, it could be the contact with the magnets slowing it down. The reason my battery was draining was because the magnets had to use so much energy to start, it would kill the chances of being able to restart it. If this is your symptom, make sure you dont have rust on the armiture and the flywheel.

Thanks everyone again.

Bill

I don't want to argue either, but I do want info here to be accurate, since these posts are archived and often used as reference for other folks with the same problem.

The flywheel and coil are generally already rusted on most small engines before they ever get bought by the consumer. They are bare metal and rust over rapidly, even when kept indoors. You say "The reason my battery was draining was because the magnets had to use so much energy to start, it would kill the chances of being able to restart it." This can't be, because the flywheel magnets don't use battery power, aren't connected to the battery, and aren't used to turn the engine. Your valves were the major contributing factor and probably the sole factor that caused the engine to be hard to crank.

The compression release opens one of the valves just slightly so that the engine can get past the compression stroke. The engine designers made it this way because the starter was not strong enough to crank the engine without a compression release. This compression release bumps the valve open just a few thousandths of an inch by putting a little extra lift on the camshaft lobe only during cranking. What if the valve is out of adjustment by just a few thousandths of an inch? Then the compression release doesn't work, because instead of opening the valve a little, it just closes the gap in between the roker arm and valve, since it has too much of a gap there. That means the compression release in rendered ineffective, and the starter can barely crank the engine like that.

I don't mind a debate or differing views as long as it is civil and productive, and is based on proveable fact rather than circumstance.;)

I don't mind a debate or differing views as long as it is civil and productive, and is based on proveable fact rather than circumstance.;)

And my proveable fact is that the engine didn't start until we removed the rust. The valves were NOT (in my case) the main contributing factor in getting the engine to start. And yes, you are correct that the the battery does not directly send electricity to the armiture, but it does send electricity to the solenoid and starter, which both have to work in getting the armiture the electricity it needs to get the flywheel moving.

My problem solving went like this:

Changed the spark plug (it had some residue on it and was old).
Changed the oil.
Adjusted the valves.
Changed the solenoid.
Cleaned the ground wire in the back by the battery.
Up to that point, nothing worked.
We removed and sanded the armiture and flywheel.
At that point, the engine cranked perfect every time.
We heard a tapping in the engine.
We readjusted the valves.
Engine runs smoother.

End conclusion? It was the magnetic connection (or lack thereof) that was causing more issue than the valves. My bet is (since I could get it to run after I charged the battery) that the valves should have never been touched, because when it ran prior to our first valve adjustment attempt, it did not have that tapping sound. I probably did more harm than good.

Why does everything have to always be about adjusting the valves? I am trying to tell you all what worked for me. This could be an easy solution to a lot of people's problems. It is worth a shot to try this first, BEFORE you go screwing with the valves. I just don't get why you are telling me what was more effective, when I was the one here working on the tractor. I know what we did and I know what worked. Your logic is not flawed, but for some reason it just doesn't apply to my case.

Just make sure you have TWO sets of feeler guages to correctly gap the armiture.

Everything doesn't have to be about the valves, but in your situation, the only thing you did that can affect how the engine turns is adjust the valves, change the solenoid, or clean the ground wire. The armature has absolutely nothing to do with the engine turning. The armature can be GONE and the engine will still crank. That's why I maintain sanding it didn't help the cranking over issue. There is no "magnetic connection" to be made, and no electricity required by the armature. The armature will work with no battery at all, and still fire the spark plug.

That is fact, unlike your theory about how the armature needs an some "magnetic connection" to "get the flywheel moving" somehow via the starter and solenoid. That's why I said "proveable fact". The theories you are providing are not how the engine works. The armature doesn't have anything to do with the engine cranking.

If adjusting the valves did more harm than good, you adjusted them wrong. Look at your owners manual and read about the importance of adjusting the valves on a regular basis, as part of routine maintainence. I get tons of them every year in my shop with the same problem. Seems like every few years, they get out of adjustment bady enough to disable the compression release.

Was the valve adjustment what made yours easier to crank? I don't know, it could be the cleaned ground cable or the new solenoid, but I do know it wasn't the sanding of the flywheel. Possibly in the process of sanding the flywheel you moved a wire or inadvertently did something else that fixed the problem, I don't know.

I am going to withdraw politely now, because too often I see these discussions turn bad and I fear that I sense frustration developing in your reply. I have no hard feelings or intend no disrespect. If you can prove with something other than circumstance (the fact that it truned after you sanded the flywheel) that the rust was causing the problem, I will cheerfully eat my words.

Really I guess it doesn't matter anyway...your engine is fixed, my point has been made as well as yours, so viewers can look, read, and decide what action to take based on their own judgement. I guess I'm just the type that when I know I'm right, I'll spare no expense to defend my position. Sometimes it's a blessing, sometimes it's a curse.

Everything doesn't have to be about the valves, but in your situation, the only thing you did that can affect how the engine turns is adjust the valves, change the solenoid, or clean the ground wire. The armature has absolutely nothing to do with the engine turning. The armature can be GONE and the engine will still crank. That's why I maintain sanding it didn't help the cranking over issue. There is no "magnetic connection" to be made, and no electricity required by the armature. The armature will work with no battery at all, and still fire the spark plug.

That is fact, unlike your theory about how the armature needs an some "magnetic connection" to "get the flywheel moving" somehow via the starter and solenoid. That's why I said "proveable fact". The theories you are providing are not how the engine works. The armature doesn't have anything to do with the engine cranking.

If adjusting the valves did more harm than good, you adjusted them wrong. Look at your owners manual and read about the importance of adjusting the valves on a regular basis, as part of routine maintainence. I get tons of them every year in my shop with the same problem. Seems like every few years, they get out of adjustment bady enough to disable the compression release.

Was the valve adjustment what made yours easier to crank? I don't know, it could be the cleaned ground cable or the new solenoid, but I do know it wasn't the sanding of the flywheel. Possibly in the process of sanding the flywheel you moved a wire or inadvertently did something else that fixed the problem, I don't know.

I am going to withdraw politely now, because too often I see these discussions turn bad and I fear that I sense frustration developing in your reply. I have no hard feelings or intend no disrespect. If you can prove with something other than circumstance (the fact that it truned after you sanded the flywheel) that the rust was causing the problem, I will cheerfully eat my words.

Really I guess it doesn't matter anyway...your engine is fixed, my point has been made as well as yours, so viewers can look, read, and decide what action to take based on their own judgement. I guess I'm just the type that when I know I'm right, I'll spare no expense to defend my position. Sometimes it's a blessing, sometimes it's a curse.

I have plenty of messageboard experience to know not to start thowing insults. It's classless.

All I know is what worked in my situation. Call it a theory, call it stupid, call it wrong. What happened, happened. The only thing that got my tractor to start freely with the spark plug in was sanding some thick rust off the armiture and the flywheel. You are correct that I don't necessarily know all there is to know about engines, or this engin in particular. Never claimed to. I am a novice. All I am trying to relay is what worked for me. It wasn't the valves, and the reason I believe that it wasn't the valves is because the tractor would start once, run extremely well, but then couldn't be restarted. The only 2 things that got that flywheel to spin freely was sand paper or removing the spark plug.

Maybe it was the amount of rust? I would spray the engine down almost religiously. I can't explain it. All I can do is tell you what happened, and tell you that I firmly believe it was not the adjustment of the valves. It's fine if that is normal maintenance, but in my case, I don't think it was completely necessary.

Ok...sounds like you're still cool then. I know how easily some folks flare up over a disagreement when they're online. (not that you're that type, but ya never know). I may come across bluntly, but when the train of thought gets rolling, I just type. No offense intended by it.

So, as long as we're still on friendly terms, let me ask...if the engine turned easily with the spark plug out, why would the rusty flywheel care if the plug was in or out? What changes when the plug is put in? Nothing except the compression factor. Now, with the plug installed, the engine can't blow the air out of the cylinder through the plug hole. It has to compress it. If the engine can't turn anymore because of this, it is because the compression is too great. (compression release not effective because of excessive valve clearances).

Think about this...the magnets on the outside of the flywheel serve only one purpose. They induce current in the coil windings and tell the coil when to fire by passing by the armature legs. They don't touch anything, just pass by. The armature is magnetic and can pick up the magnetic field whether it's rusty or not, just like a magnet will pick up a rusty nail as easily as a clean nail. The magnet and the coil armature are only related to the firing of the spark plug. The cranking over of the engine is done by the battery, solenoid, and starter, all of which are entirely independent of the magnets on the flywheel or the armature.

So, the only thing that changed by your removing or installing the plug was the engine's compression....and the only thing you did to the mower that would change compression is adjust the valves.

This horse is going to be un-recognizeable when we get done with it, lol!

Like I said, I can't explain it. All I know is that removing the rust got it to start. I hear what you are saying, and it makes complete sense, but something doesn't add up.

Like you said, who cares. It's working, and that's all that matters...

http://209.85.48.11/9139/55/emo/beer.gif

Scott,

Can you put your fingers on the fuel solenoid and feel/hear it click when you turn the key switch on and off ?

Could be a piece of trash hanging it closed.....It could be bench tested out of the carb with jumper leads to assure it's fully opening/retracting.

Sounds to me that you have a problem with a fuel pump.