My tractor starts sometimes for a few seconds, on full choke, and stops. It doesn't start thereafter. Changed spark plug and fuel filter. Ran couple of times this season as well

Try starter fluid to determine whether its a fuel problem or spark. Remove air filter cover and filter and spray a short burst (about 1 second) of fluid into carb throat (or as close as possible behind baffle C) and promptly pull starter cord.

If engine fires and runs for a second or two then its a fuel/choke problem (compression is ok). If doesn't run, then more likely no spark but could still be a fuel or compression issue.

Hi Mike:
It's trying to make you crazy.
I have a model YT4000 and it is a PITA to start when cold.
I pull the air filter, toss in a bit of gas to prime it, and it starts instantly.

I'd suggest that you give yours another try. 3 or 4 times of a couple of seconds each. If it doesn't go, pull a spark plug and see if it is wet or dry. Wet indicates getting gas but no spark. Dry indicates not getting gas.
While you have the plug out, check the spark... Hot & blue.
Hope this gives you some more to work with.

Ignition module is failing

Check fuel intake screen on bottom of pickup in fuel tank. Possibly floating debris.

Try changing your fuel filter and also clean the air filter too. the machine is starved for fuel

Many times a dirty air filter will cause this on this style of engine. When the filter is plugged, it creates a 'rich' fuel condition, and the engine smokes heavily, the excess carbon is drawn into the air filter, and plugs it even more.

check spark plugs, air filter, fuel filter, choke linkages (for full choke/no choke operation) and crankcase oil.

Crankcase oil can become fuel contaminated, thus overfilling the crankcase and filling the crankcase breather with raw oil/fuel, and this is drawn into the air filter, plugging it, and starting this senerio.

If there is fuel in the crankcase oil, drain completely, and refill with fresh oil. Then you need to look towards the carb for an inlet needle sticking, broken, worn.

I’m happy to assist further over the phone at https://www.6ya.com/expert/rolandw_c013176d62ee17ae

you could have water in gas,look in the gas tank for any bubbles floating on bottom of tank this is water empty gas from tank and remove carburetor bowl too remove water from it .

Hi and welcome to FixYa,

Initially, a few possibilities you may want to check/explore:

• stale gasoline;
• clogged fuel filter (inside the tank above the fuel shutoff valve;
• clogged, bocked, varnished, gummed carbs, jets, air pin holes;
• stuffed air filter/box;
• vacuum leak (rubber coupling, manifold side);
• air leak (airbox base assembly seated/fitted on the carbs.

Basically, a general cleanup of the fuel lines, tank and the carbs. Sitting for some time tends to leave varnish like coating on most parts.

Good luck and Thank you for using FixYa. Happy Holidays.

First of all, make sure you have followd the correct start up procedure.
(1)Throttle on and locked in start position, (2)choke on and pull a few times. Saw should fire briefly and cut out. (3)Now switch to idle (half choke if applicable) and pull another couple of times. Saw should now fire and run. If you have pulled it too many times in the full choke position you will have flooded the engine. To rectify this you will need two people. One of you should hold the machine steady on the ground with no choke on and throttle fully open. The other should also steady the machine and pull the starter in quick succesion. This could take ten or so pulls but it should start the engine in the case of flooding. Sometimes it will splutter a couple of times before fully starting and it will normally bog down a bit for the first few seconds as it spits out the excess fuel/oil mix.
If you got to point (3) as it shown above, and then the saw wouldn't start, or hadn't fired and died then there could be a few different problems. basic checks are for, clean filter, fresh/clean fuel, clean spark plug (ie, not oily/choked with carbon build up). When checking the spark plug, if it has fuel/oil mix on it then ther is probably aeither a compression problem/air leak or no spark. To check for a spark leave the plug unscrewed but fitted into cap, rest it against a metal part of the saw and pull the starter with the elec switch on. You should see a healthy blue spark. WARNING, do not rest the spark plug near the plug hole as if it does spark it could ignite any fuel/oil mix that is pumped out of the cylinder. I've had many a singed eyebrow from this happening. If there is no spark, check to make sure the cap is attatched securely to the lead,and try repacing the plug. If this doesn't help you will need to get the coil, ht lead and wiring tested.

Hi
I found that the plug that came with my unit had an intermittent fault (sparked sometimes, then not all) definately the plug in my case. And yet at first, seemed to start OK, progressively got worse.

OK so youve changed the plug! Now check for spark....Can you see the spark if you pull the cord a few times
(you have to unscrew the plug from the head but leave it connected to lead & rest the plug against the metal cylinder surface using a pair of pliers to steady it and so you dont get a small shock)

If youre getting visable spark when you pull the cord, suspect fuel feed blockage from carb, Test by: Prime the bulb & turn to full choke, pul the start cord, Is there petrol vapour/odour present within the cylinder with the spark plug removed.

Check also gauze air filter behind the roto choke knob is clear, on/off switch (could be damp wd40) Test compression put your finger over the open plug port, plug starter cord, should be a little pressure build up

Hope this helps
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Aky1967