Tried everything listed, pls advice what else to check.

Y

YTA18542

Forum Newbie
Husqvarna model YTA18542-960480067
Briggs and Stratton 33S777-0001-G1
92hrs on meter
sat in a neighbor shed for a long time.
currently engine turns and sputters but would not run, unburnt fume/smoke/ come out of exhaust, occasionally from intake

Electrical- new battery charged, starter good, solenoids wires and grounds have been tested for continuity and resistance.
Spark- plug and coil is old but tested for good spark.
Oil- level good, currently old, but very clean from years ago.
Compression- flywheel spins with resistance, plug installed.
Valves- valve cover removed, intake.003 exhaust.005, no adjustment needed.
Timing- checked when plug and valve cover off, magnet position and TDC seems aligned.
Fuel- fuel tank emptied and cleaned, fuel inline clear and new filter, flow is about 400ml/min at carb more than enough.
Nikki Carb- bottom solenoid operates freely. auto choke/ manual choke normal. removed carb, throttle plate and chock plate moves freely, Bowl is extremely clean, drained fuel has no water. ran fine wire through all holes found no Blockage.
what to resort the forum before I tear entire thing apart

What else am I missing? I’m going nuts.
Thank you, ANY thoughts are welcomed.
 
Try a known good plug. Just because the plug sparks outside the compression zone doesn't mean it will spark under compression load.
 
Also pull the blower housing off & remove the kill wire which will isolate a wiring problem
when I have one of these I fit an inline spark tester to check that I am getting a spark every revolution .
The valve lash sounds right but are the vales protruding the same length into the rocker housing they are identical as is the cam lobes .
 
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Do a leak down test or try checking the compression and let us know what you see????
Fumes and smoke out of exhaust is a hint.

You can do a leak down just injecting about 20-30 psi air into the spark plug hole using a rubber tipped air gun with the engine locked at TDC. Listen for air out the EX, intake or into the oil galley.
 
Try spraying gumout carb cleaner in the throat of the carb while spinning it over to see if it will run on it.
 
Take the valve cover off, and rotate the flywheel by hand, and watch the rocker arms, make sure that the open close their valves at about the same distance. Make sure that one of the cam lobes isn't rounded off.
 
bertsmobile1 said:
Also pull the blower housing off & remove the kill wire which will isolate a wiring problem
when I have one of these I fit an inline spark tester to check that I am getting a spark every revolution .
The valve lash sounds right but are the vales protruding the same length into the rocker housing they are identical as is the cam lobes .
Click to expand...
Blower is off, but what is the kill wire?
 
shadetree#1 said:
Do a leak down test or try checking the compression and let us know what you see????
Fumes and smoke out of exhaust is a hint.

You can do a leak down just injecting about 20-30 psi air into the spark plug hole using a rubber tipped air gun with the engine locked at TDC. Listen for air out the EX, intake or into the oil galley.
Click to expand...
thanks, i don’t have a compression gauge at home. But i did shove a rubber tip into the spark plug hole with 40psi, TDC on compression stroke, no Hissing at all.
 
Fish said:
Take the valve cover off, and rotate the flywheel by hand, and watch the rocker arms, make sure that the open close their valves at about the same distance. Make sure that one of the cam lobes isn't rounded off.
Click to expand...
Thanks, they do travel the same distance, and valves seals fairly well on TDC compression stroke. I’ve put everything back now, and I’ll try to start it with some starting fluid, wish Me luck. Taking the engine apart will be my last step If it still won’t run.
 
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