Husqvarna 322 line trimmer wont start

[Mad_mat222]

Greetings,
Riddle me this, working on a 322L that wont start.

I have spark. Air gap is correct. Swapped plugs and both producing good spark.

Removed flywheel and confirmed timing.

Have fuel with no blockages or restrictions. When pull starting and plug out, fuel vapor evident and coming out of spark plug hole. Reset carb to scratch settings. No change. Swapped carb from running machine. Nil change and machine i swapped the other carb on to started first pull.

Good compression. Inspected piston through spark plug hole and exhaust port. Very minimal wear and no sign of damage.

Overall no obvious signs of damage and base gasket still appears in good shape. I did tighten the jug screws a smidge but this was more for elimination than a requirement.

I am completely stumped. I have fuel, air, spark and compression and its all happening at the right time. GRRRRRRRRRRRRRR

Any suggestions?

 

[bertsmobile1]

Compression on those is 100psi minimum
And you need a special compression tester for them because the volume is so small expansion in the hoses will affect the results
Some times I need to go 30 or more pulls

 

[Mad_mat222]

Compression is good!

 

[Oddjob]

Compression is good!

I do not claim great expertise, but here are my thoughts.

You didn’t mention air. How is the filter? Try starting it without the filter.

If you have gas, spark, compression, timing and air, then it must start. So, something doesn’t compute and you have to go back and reevaluate your conclusions.

Could the shutoff wire that grounds the coil be shorting out? (Is the switch in the run position?) I would disconnect the wire at the coil and see if that solves it. If not, then I’d shoot some starting fluid into the cylinder and see if it fires. If it does, you have a fuel problem. How fresh is your gas? I heard you say it has compression, but you didn't say you tested it. Someone here gave me this great advice, remove the plug and put your thumb over the hole. Pull the starter cord and you should not be able to keep your thumb on the hole. Valves not working properly can screw up compression. Is the exhaust side obstructed? Does your machine have one of those screens that clog up?

It is possible to have visible spark, but it is weak. You’ve already replaced the plug, so maybe you have a weak ignition coil. Do you have one you can swap from a working machine, like you did with the carb?

I’ll tap out and let actual experts have a go. Good luck.

 

[Mad_mat222]

Mystery solved. I swapped the coil and it started first pull. So frustrating. The spark was jumping over 10mm on the tester. Obviously something going on. I wasted alot of time on that machine but im so stubborn I didnt want it to beat me. The only thing I had left to swap out was the pull cord Anyway hope that helps someone.