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did I blow it up?
#1
C
cjben
C
cjben
This is for a craftsman LT2000 with the intek 17.5 engine. I was cutting tall grass yesterday and hit a t shirt which of course got wrapped around the blades. Mower died instantly and will not restart. There is gas in the tank. I checked for spark,there is small spark when I ground the spark plug against the frame. I am not sure how big the spark should be for a small engine. It would not be enough to start a gas v8 from what I remember of my gear head days. When I put my finger over the spark plug hole and crank the engine over,I can feel air come out,so there is compression. I know it's a no no but I sprayed a little starting fluid in the carb and tried starting it just to see if it is a fuel problem. It only pops a couple times through the carb but didn't backfire or try to start. Before I start throwing money at it,is there any other troubleshooting things I can do? I have just about zero experience with small engines besides changing oil,air filters and spark plugs. Thanks for any help!!:wink:
#2
cpurvis
cpurvis
This ordinarily doesn't happen to indirect (belt) drive engines but a sudden stoppage of the engine can shear the flywheel key. If the flywheel slips on the crankshaft, the ignition timing is thrown out of whack.
If this is a vertical shaft engine, it shouldn't be too hard to check.
If this is a vertical shaft engine, it shouldn't be too hard to check.
#4
cpurvis
cpurvis
I can't give you exact details because I'm not familiar with your engine. In generic terms, you need to remove anything that obstructs your access to the flywheel/crankshaft junction. That is usually the blower housing which may have other things attached to it. Once there, you will see a keyway in both the flywheel and crankshaft. These keyways are held in alignment with a 'key', usually a Woodruff key. They must line up exactly, as this is what controls the ignition timing of the engine.
Not a particularly difficult job if you have the tools and know how to use them. But definitely more involved than, say, replacing blades or changing oil.
Not a particularly difficult job if you have the tools and know how to use them. But definitely more involved than, say, replacing blades or changing oil.
#5
T
Txbiker
T
Txbiker
Good advice with the key and the most likely culprit. You know when you blow one up. My 16h.p. intek grenaded on my LT 1000 2 weeks back. Loud pop splash of oil on the muffler puff of smoke then the rest of the oil on the ground.
#6
C
cjben
Ok. finally had time to work on it some today. The crankshaft and keyway in the flywheel are still lined up and haven't moved. The key is still there and not broken. What else could I check? How strong is the spark supposed to be? Obviously not a fuel problem or it should have fired off with the starting fluid. Just need other ideas of what to check.
C
cjben
Good advice with the key and the most likely culprit. You know when you blow one up. My 16h.p. intek grenaded on my LT 1000 2 weeks back. Loud pop splash of oil on the muffler puff of smoke then the rest of the oil on the ground.
Ok. finally had time to work on it some today. The crankshaft and keyway in the flywheel are still lined up and haven't moved. The key is still there and not broken. What else could I check? How strong is the spark supposed to be? Obviously not a fuel problem or it should have fired off with the starting fluid. Just need other ideas of what to check.
#7
cpurvis
cpurvis
As the engine was running at the time:
1. The spark was adequate to run the engine just prior to taking on the t-shirt. What could a sudden stop do to change that?
2. Fuel was being delivered in a combustible ratio prior to the sudden stop. What could a sudden stop do to change that?
3. There was adequate compression prior to the sudden stop. What could a sudden stop do to change that?
4. The ignition timing was correct prior to the sudden stop. What could a sudden stop do to change that?
I'm pretty sure the answer to the first two is "Nothing."
Since you still have compression, the answer to #3 is "Nothing."
That only leaves #4. A sudden stop can do plenty to change that, BUT...it usually doesn't happen to belt drive mowers. Unlike mowers that have the blade attached directly to the crankshaft, there is a cushioning effect caused by slippage of the belts.
Did you remove the flywheel and examine the key? That would be my next step because I can't see any reason to pursue #1, 2 or 3.
Of course, I could be wrong.
1. The spark was adequate to run the engine just prior to taking on the t-shirt. What could a sudden stop do to change that?
2. Fuel was being delivered in a combustible ratio prior to the sudden stop. What could a sudden stop do to change that?
3. There was adequate compression prior to the sudden stop. What could a sudden stop do to change that?
4. The ignition timing was correct prior to the sudden stop. What could a sudden stop do to change that?
I'm pretty sure the answer to the first two is "Nothing."
Since you still have compression, the answer to #3 is "Nothing."
That only leaves #4. A sudden stop can do plenty to change that, BUT...it usually doesn't happen to belt drive mowers. Unlike mowers that have the blade attached directly to the crankshaft, there is a cushioning effect caused by slippage of the belts.
Did you remove the flywheel and examine the key? That would be my next step because I can't see any reason to pursue #1, 2 or 3.
Of course, I could be wrong.
#8
C
cjben
Here is something I forgot I did when I hit the shirt: Like a dummy I tried to start it right after I hit the shirt. The engine turned over real slow of course because the shirt was wrapped around the blades. Could this have caused a problem? I think I have a compression gauge from my shade tree mechanic days. Would that work for a mower engine? Is there any fuses I could have blown trying to start it under stress? I will take the flywheel off and check the keyway to be sure,but it doesn't look like it has been moved at all. Thanks for your help so far!!
C
cjben
As the engine was running at the time:
1. The spark was adequate to run the engine just prior to taking on the t-shirt. What could a sudden stop do to change that?
2. Fuel was being delivered in a combustible ratio prior to the sudden stop. What could a sudden stop do to change that?
3. There was adequate compression prior to the sudden stop. What could a sudden stop do to change that?
4. The ignition timing was correct prior to the sudden stop. What could a sudden stop do to change that?
I'm pretty sure the answer to the first two is "Nothing."
Since you still have compression, the answer to #3 is "Nothing."
That only leaves #4. A sudden stop can do plenty to change that, BUT...it usually doesn't happen to belt drive mowers. Unlike mowers that have the blade attached directly to the crankshaft, there is a cushioning effect caused by slippage of the belts.
Did you remove the flywheel and examine the key? That would be my next step because I can't see any reason to pursue #1, 2 or 3.
Of course, I could be wrong.
Here is something I forgot I did when I hit the shirt: Like a dummy I tried to start it right after I hit the shirt. The engine turned over real slow of course because the shirt was wrapped around the blades. Could this have caused a problem? I think I have a compression gauge from my shade tree mechanic days. Would that work for a mower engine? Is there any fuses I could have blown trying to start it under stress? I will take the flywheel off and check the keyway to be sure,but it doesn't look like it has been moved at all. Thanks for your help so far!!
#9
cpurvis
cpurvis
I'm not sure how you could have cranked the engine with the blades engaged. That isn't supposed to happen, but if it did, you didn't hurt anything.
A compression gage just measures pressure; it doesn't know what kind of engine it's attached to. I don't think that's an issue but go ahead and check it if you like.
If the starter spins the engine, I don't think you have a fuse problem. Unless I'm mistaken, the Briggs engine needs no external source of electricity to run. All it needs is electricity to spin the engine.
A compression gage just measures pressure; it doesn't know what kind of engine it's attached to. I don't think that's an issue but go ahead and check it if you like.
If the starter spins the engine, I don't think you have a fuse problem. Unless I'm mistaken, the Briggs engine needs no external source of electricity to run. All it needs is electricity to spin the engine.
#10
S
spacecowboy
S
spacecowboy
What does "won't restart" mean?
Does it crank?
Is there a click when you push the button or turn the key?
Or, when you attempt to start does it do nothing? Meaning it does nothing there is no audio sound? It does not crank or make any sound?
You'll need to forget the tshirt and act like its a brand new problem.
So 1st determine whether it is a gas issue or an electrical issue? Then troubleshoot from there.
But change the spark plug 1st and shoot some gas or starter fluid into the carburetor and see if it starts.
Look for the obvious first.
Is the connection to the battery alright?
Does it have gas in the tank?
Is your PTO engaged?
Do you have to sit on the seat to start?
Is the spark plug wire fully seated?
Does it require that your clutch/brake is depressed fully?
Eliminate all obvious and operational errors 1st.
I don't think you blew it up. I don't think you did anything to it other than running over the tee shirt and binding the blade to stop the engine. I think the problem is a very simple and obvious one that's hiding right in front of you.
Good luck!
Does it crank?
Is there a click when you push the button or turn the key?
Or, when you attempt to start does it do nothing? Meaning it does nothing there is no audio sound? It does not crank or make any sound?
You'll need to forget the tshirt and act like its a brand new problem.
So 1st determine whether it is a gas issue or an electrical issue? Then troubleshoot from there.
But change the spark plug 1st and shoot some gas or starter fluid into the carburetor and see if it starts.
Look for the obvious first.
Is the connection to the battery alright?
Does it have gas in the tank?
Is your PTO engaged?
Do you have to sit on the seat to start?
Is the spark plug wire fully seated?
Does it require that your clutch/brake is depressed fully?
Eliminate all obvious and operational errors 1st.
I don't think you blew it up. I don't think you did anything to it other than running over the tee shirt and binding the blade to stop the engine. I think the problem is a very simple and obvious one that's hiding right in front of you.
Good luck!
#11
C
cjben
ok,here is what I did today. pulled the valve cover and turned the engine over by hand. valves move,so I know one of them isn't broke. Did a compression test and got a zero reading,but not real sure my gauge actually works,been 15 years since I've used it. I did notice when I was cranking the engine with the key while doing the compression test,there was A TON of oil blowby coming out of the dipstick tube and what smelled like gas/blowby coming out of the carb. I have attached a picture of what the key/crankshaft looks like. looks normal to me. If you look close,you can still see the key in the keyway and lined up correctly.
C
cjben
What does "won't restart" mean?
Does it crank? yes
Is there a click when you push the button or turn the key?
Or, when you attempt to start does it do nothing? Meaning it does nothing there is no audio sound? It does not crank or make any sound?cranks just fine ou'll need to forget the tshirt and act like its a brand new problem.
So 1st determine whether it is a gas issue or an electrical issue? Then troubleshoot from there.
But change the spark plug 1st and shoot some gas or starter fluid into the carburetor and see if it starts.
Look for the obvious first.
Is the connection to the battery alright?yes
Does it have gas in the tank?yes
Is your PTO engaged?no
Do you have to sit on the seat to start?not if the brake is locked
Is the spark plug wire fully seated?yes
Does it require that your clutch/brake is depressed fully?yes
Eliminate all obvious and operational errors 1st.
I don't think you blew it up. I don't think you did anything to it other than running over the tee shirt and binding the blade to stop the engine. I think the problem is a very simple and obvious one that's hiding right in front of you.
Good luck!
ok,here is what I did today. pulled the valve cover and turned the engine over by hand. valves move,so I know one of them isn't broke. Did a compression test and got a zero reading,but not real sure my gauge actually works,been 15 years since I've used it. I did notice when I was cranking the engine with the key while doing the compression test,there was A TON of oil blowby coming out of the dipstick tube and what smelled like gas/blowby coming out of the carb. I have attached a picture of what the key/crankshaft looks like. looks normal to me. If you look close,you can still see the key in the keyway and lined up correctly.
Attachments
#12
cpurvis
cpurvis
You said early that you held your thumb over the spark plug hole and it had compression. That and the fact that it was running at the time leads me to believe it has compression. Being an ex-gearhead, you can probably tell if an engine has no compression by the sound it makes while cranking.
Seeing fumes coming from the crankcase vent is normal. All engines are pumps and the air in the crankcase gets compressed by the piston moving downward. It has to go somewhere. Likewise it has to allow air back into the crankcase when the piston moves upward. Single cylinder engines are among the worst in this regard. Multi cylinder engines have this pumping minimized by having some pistons moving up and some moving down at the same time, thus canceling each other out.
I can't think of anything that a sudden stoppage could do to cause the engine to not have compression unless the compression release is somehow holding a valve open. Make sure that both valves are closing fully.
Seeing fumes coming from the crankcase vent is normal. All engines are pumps and the air in the crankcase gets compressed by the piston moving downward. It has to go somewhere. Likewise it has to allow air back into the crankcase when the piston moves upward. Single cylinder engines are among the worst in this regard. Multi cylinder engines have this pumping minimized by having some pistons moving up and some moving down at the same time, thus canceling each other out.
I can't think of anything that a sudden stoppage could do to cause the engine to not have compression unless the compression release is somehow holding a valve open. Make sure that both valves are closing fully.
#13
C
cjben
C
cjben
cpurvis,did you look at the picture of the keyway? does that look good to you? By crankcase vent,you mean dipstick tube because that is where the blowby,actually oil was spraying out? also blowby/maybe gas coming out of the carb. It does seem like the timing is off,but everything is lined up so I don't think that is it.
#14
cpurvis
cpurvis
Yes, I looked at it and it does look OK.
Yes, the dipstick tube is all part of the crankcase.
I'm afraid I don't have any other suggestions to offer. Sorry.
Yes, the dipstick tube is all part of the crankcase.
I'm afraid I don't have any other suggestions to offer. Sorry.
#15
C
cjben
Thanks for the help!! just seems like I am missing something simple. For whatever reason,the engine did crank when the shirt was caught in the blades even though I had the blades shut off. Almost seems like it isn't getting enough spark because of a safety feature or something but I doubt a 10 year old lt2000 is that sophisticated. Wifey is threatening to go buy me a new one,have to get it running before she does that!!:thumbsup:
C
cjben
Yes, I looked at it and it does look OK.
Yes, the dipstick tube is all part of the crankcase.
I'm afraid I don't have any other suggestions to offer. Sorry.
Thanks for the help!! just seems like I am missing something simple. For whatever reason,the engine did crank when the shirt was caught in the blades even though I had the blades shut off. Almost seems like it isn't getting enough spark because of a safety feature or something but I doubt a 10 year old lt2000 is that sophisticated. Wifey is threatening to go buy me a new one,have to get it running before she does that!!:thumbsup:
#16
ILENGINE
ILENGINE
Have you tried using a different spark plug. Today's plugs are fragile and will do weird things, like have spark when grounded but not under compression.
#17
C
cjben
Well,put a new plug in today. And if it wasn't broke before,I think it is now. :thumbdown: Tried to start it and HUGE pop and backfire through the carb. kids came running out and asked me what I was shooting at.:laughing: so I think the spark is good now,but still acts like it is out of time. Maybe I'll take the wifey up on her offer. bout tired of messing with this pos.:mur:
C
cjben
Have you tried using a different spark plug. Today's plugs are fragile and will do weird things, like have spark when grounded but not under compression.
Well,put a new plug in today. And if it wasn't broke before,I think it is now. :thumbdown: Tried to start it and HUGE pop and backfire through the carb. kids came running out and asked me what I was shooting at.:laughing: so I think the spark is good now,but still acts like it is out of time. Maybe I'll take the wifey up on her offer. bout tired of messing with this pos.:mur:
#18
C
cjben
Does anybody think I could have bent a valve when I tried to start the engine with the blades still on? Engine cranked over real slow like it was under pressure,well because it was. lol How hard is it to replace and adjust the valves?
C
cjben
Well,put a new plug in today. And if it wasn't broke before,I think it is now. :thumbdown: Tried to start it and HUGE pop and backfire through the carb. kids came running out and asked me what I was shooting at.:laughing: so I think the spark is good now,but still acts like it is out of time. Maybe I'll take the wifey up on her offer. bout tired of messing with this pos.:mur:
Does anybody think I could have bent a valve when I tried to start the engine with the blades still on? Engine cranked over real slow like it was under pressure,well because it was. lol How hard is it to replace and adjust the valves?
#19
B
bertsmobile1
B
bertsmobile1
Get a new head gasket & pull the head off.
Good chance you will find something stuck under the inlet valve holding it open
Other than that, the cam is cactus.
Good chance you will find something stuck under the inlet valve holding it open
Other than that, the cam is cactus.
#20
F
FahkNutz
F
FahkNutz
Symptoms are broken flywheel key. Possibly the key broke, engine spun full turn and stopped with key-way, aligned again on broken key. Timing is now way off, by 180 degrees. Need a flywheel puller and a $1.65 flywheel key.
#21
cpurvis
Re-think that.
Small engines fire at TDC, no matter if it's on compression or not. I think the name for it is 'Maverick' ignition.
cpurvis
Symptoms are broken flywheel key. Possibly the key broke, engine spun full turn and stopped with key-way, aligned again on broken key. Timing is now way off, by 180 degrees. Need a flywheel puller and a $1.65 flywheel key.
Re-think that.
Small engines fire at TDC, no matter if it's on compression or not. I think the name for it is 'Maverick' ignition.
#22
B
bertsmobile1
Did Maverick take drugs ?
Wasted Spark ignition is the name for 4 strokes that fire every revolution.
B
bertsmobile1
Re-think that.
Small engines fire at TDC, no matter if it's on compression or not. I think the name for it is 'Maverick' ignition.
Did Maverick take drugs ?
Wasted Spark ignition is the name for 4 strokes that fire every revolution.
#23
F
FahkNutz
Any updates?
F
FahkNutz
Does anybody think I could have bent a valve when I tried to start the engine with the blades still on? Engine cranked over real slow like it was under pressure,well because it was. lol How hard is it to replace and adjust the valves?
Any updates?
#24
R
Regwal
R
Regwal
Make a static timing light with a 12v bulb and #12 wire. Search web for instructions on [static timing small engines] and apply to your engine. I'll bet you find something!
#25
B
bertsmobile1
Unless your engine is a very old one with points tryingthis will fry the chip that controls your spark timing and you will be up for a new module $$$$$$$
B
bertsmobile1
Make a static timing light with a 12v bulb and #12 wire. Search web for instructions on [static timing small engines] and apply to your engine. I'll bet you find something!
Unless your engine is a very old one with points tryingthis will fry the chip that controls your spark timing and you will be up for a new module $$$$$$$
#26
R
Regwal
R
Regwal
You are correct Bert and that is why I suggested doing a search. There is a lot of information on the web from different sources and only using "one" can get a person into lots a trouble.