LT2000 won’t start

jerrycmorrow said:
LT2000, type 917273760, Engine - 31H777-0297-E1
Went to run it and started and ran for about 30 seconds. Installed new Chinese carb last year and ran great all summer. Suspected condensation so took carb off and drained, cleaned with carb cleaner, dried with compressed air, reinstalled, put new fuel. No start
I’m being a little lazy plus my mower is stored outside, under cover, and it’s too cold to work on it unless I can zero in on the problem. Anyone can help?
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the first thing you do is squirt some gas down the throttle body to see if it thumps. If so, it's likely a cold fuel pump vacuum line not sealing, allowing air in keeping it from working. spray the hose connections with a little oil/gas mix to seal them, then squirt some starting fluid in the carb. that should do it.
 
jerrycmorrow said:
This is the valve cover. You can see the code is not within the mentioned range
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Jerry don't waste your money on a carb kit until you know you need it, that engine by the code date should have a Walbro carb., but double check and make sure it's not the Nikki. Also spray some starting fluid or Deep Creep into the intake and see if it will start, if not it may not be a fuel issue and could be spark.
 
If you have a gravity-fed fuel system, you will want a filter with 75 micron rating down to maybe 30 or 50 microns. (The smaller that number, the more it filters (i.e. restricts) fuel flow...) The red Briggs filter is 150 microns. The white Briggs filter is 75 microns. When you get a see-through filter, anticipate it is 30 microns, but it could be less or more...)

Still, 30 seconds is not a lot of time, and it is probably carb-related. (Not enough time to heat up a coil to the point of failure... in my short experience.)

We use Seafoam with a lot of success. It sometimes takes 24 hours to work, but other times immediate or 1-2 hours... The Seafoam has to get to the carburetor to be effective, so dump the bowl and fuel-line to get to treated fuel... (We use more than the instructions say in very the short-term.)

Bad fuel (i.e. with dirt) can clog a fuel jet, so use a wire to clear the jet by removing the carb-bowl and cleaning the opening/jet.
 
Instead of loading the parts cannon up, troubleshooting is the path.
Others have said, but;

good compression?
good spark?
Spray carb cleaner into carb "throat" just a small squirt, close choke and try to start. trys to start, then you have a fuel delivery problem, no start then you have spark or timing problem, maybe valve adjustment.

From your description my guess is you have water in your gas or what ever killed the original briggs carb killed this one as well (plugged up with crud from gas tank.). drain you gas and see what it looks like (if you have good spark and good compression) although sitting outside it is likely there is water condensation.

the anti backfire valve is also a good suggestion if your engine has one. screws into the bottom of the carb. Unscrew that and see if it is free and apply 12 volts to it and watch that the plunger actually moves (will pull back into body of valve.
 
jerrycmorrow said:
LT2000, type 917273760, Engine - 31H777-0297-E1
Went to run it and started and ran for about 30 seconds. Installed new Chinese carb last year and ran great all summer. Suspected condensation so took carb off and drained, cleaned with carb cleaner, dried with compressed air, reinstalled, put new fuel. No start
I’m being a little lazy plus my mower is stored outside, under cover, and it’s too cold to work on it unless I can zero in on the problem. Anyone can help?
Click to expand...
The change in temperature from summer to winter may have altered an efficient fuel to air mix. You may need to tweak the settings via the screw adjustments on the carberateur- if applicable.
 
I suggest just Change to a new plug and be sure the coil wire is producing a bright spark when plugged in and grounded.
Be sure the fuel valve is turned ON. Try Starting Fluid. If it starts, you have Ignition now you need Fuel.
Needle valve or electric fuel shutoff may be stuck or inoperative. Good Luck.
 
As several others of the good troubleshooters have said, always start with giving it an external fuel source by squirting carb cleaner or some gas into the carb hole in the intake to see if it will then run for a few seconds on the fuel you have provided.
This is what you do on any of these engines that will crank and sound normal cranking speed but will not run.
It's pointless to do anything else first because this is a high probability the problem anyways and the old method of pulling out the spark plug or putting a new plug in is usually just a waste of time.
I did specify if they crank over normal speed and sound normal on cracking but just won't start because if you have one that's not cranking or cranking and then like it's hitting and bouncing off a rubber band wall... I know it's a weird description but it makes sense to me..
Then it's usually going to be an ACR, automatic compressor relief which means it will need a new camshaft to fix the problem or it's something in the valve train most commonly a loose rocker arm stud which more than not causes a push rod to bend and use the intake since it is aluminum but occasionally you will find a slipped valve guide which causes similar valve train issues and almost always a hard or weird irregular crank.
Now if you have a very fast Crank that seems too easy it's probably a popped valve seat so you have no compression.
Regardless, you start by giving it a fuel source first like a 1 to 1.5 second blast of carb cleaner and the carb hole under the air filter and crank it with the choke turned off because it's not necessary at this point.
If it doesn't start and run after two or three attempts at that then and only then is it time to pull out the spark plug because at this point you can check for spark, check for compression, and even put your finger in the hole and crank it over a few times to see if it only goes puff puff puff puff.
That means you have compression and the valves are probably working. If you get a non-operative intake valve which is common due to the bent push rod issue mentioned before, it will not just blow blow blow blow your finger out of the hole, it will blow but then it will try to suck your finger back in the hole. It should never try to suck your finger into the spark plug hole.
 
Like others have mentioned to do, one of the very first things I do with a no-start is squirt carb clean into the carb and see if it'll fire. If it does, then that eliminates everything else, & I know to focus on a fuel issue.

If you indeed have a fuel problem, drain some off the bottom of the tank into a clear glass or clear plastic container and look for water or separated ethanol settled on the bottom. If you see any of that, dump that fuel, spray out the tank and line with carb or brake clean, throw a new fuel filter on there, and add fresh fuel. You'll probably want to disassemble and clean the carb, too.

If the starter struggles to get the engine past the compression stroke, a valve adjustment is needed. You should hear the starter load up while cranking the engine - just not excessively. Light loading suggests low compression that'll need to be investigated. Just listen to what the starter is telling you. If you suspect it's low, throw a compression or leakdown tester on and see what you've got.

I've used plenty of chinese carbs over the years. Most of them actually work pretty good. Just don't expect them to hold up to any kind of moisture in the bowl. Their metals SUCK. The carbs themselves are also hit or miss. I've had good luck with them over the years, but every now and then you'll get a bad one ... or a string of bad ones. Quality control is nonexistent ... but the same can be said for ANYTHING you buy today, cars & trucks included.
 
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