Stihl MS441 Wont Start

[stcrioxstihl]

Appealing to those with experience working on 441. While I consider myself mechanically incline for whatever reason this one has me stumped. I purchased the saw, ran fine during test run, and got it home and nothing. Historically I've had good luck buying used.

Couple of notables. I am using purchased premixed fuel. The saw has steady spark. Compression is 122. I have pulled the plug to use starting fluid and fuel is getting into the carb. I cleaned the carb and found no notable debris. I did reinstall a new rubber intake as the old one had been repaired with shoe glue. I noticed the crankcase bolt near the lower right carb for the cylinder base was loose, but it had no change to compression once tightened. I replaced the impulse hose as I noticed a small crack in the line. I checked the gap of the ignition with a playing card for good measure. I ordered a new ignition too, should be here in a week.

I appreciate the help and feel awkward asking as I should be able to figure this one out.

Thanks everyone for the help. I really appreciate the site and the content!

 

[medalist]

Pull muffler and inspect cylinder/piston.
Vacuum/pressure test.
Use inline spark tester or minimally replace plug and observe spark.

Good luck.

 

[stcrioxstihl]

Will do medalist. I should have said I replaced the plug too.

 

[stcrioxstihl]

Pull muffler and inspect cylinder/piston.
Vacuum/pressure test.
Use inline spark tester or minimally replace plug and observe spark.

Good luck.

New plug and the cylinder has no scratches to speak of.

Pull muffler and inspect cylinder/piston.
Vacuum/pressure test.
Use inline spark tester or minimally replace plug and observe spark.

Good luck.

Piston is clean, no visible scratches on the intake or exhaust. Visible inspection of the rings is they also look good. Never used an inline spark tester before but this is a good excuse to try. New plug was used. Thanks again for the suggestions. After the spark test and new coil I plan to pull the jug. At a 120 PSI I would expect it to start at least. I'll keep you posted. Thanks again for the help!

 

[medalist]

Not necessarily.
Vacuum/pressure test.
Usually with some compression and enough fuel it should give a pop though.
A vacuum gauge is relatively inexpensive in comparison to wasted labor hours. Proper testing leads to a verifiable diagnosis and repeated good results.
Good luck.

 

[stcrioxstihl]

Thanks for the help medalist. Inline spark test showed that the spark wasn’t consistent. Saw is back up and going after replacing the ignition, spark plug, and adjusting the idle back to factory!

 

[medalist]

Thanks for the results.