ECHO HCS-4020

[SUKI]

Well this is on the mends now but what a fun one to troubleshoot.

Comes in not starting. Will not fire on fuel mix injection.

Tests perform. Compression >120 psi
Check for muffler blockage - none
check ignition - Good strong spark
check flywheel for shearing > none
Even changed the plug in case failure under compression.
Pressure/Vac > passed (I had to wait on the adapter for this one)

Then AVB suggested I had top of the cylinder stroke damage. Darn it if he wasn't right. Slap worn out. Must have been losing all compression right the TDC of the stroke.

So even when all the tests are there still can be something that is the problem. Now just if the customer wants to spend $350 on a $620 hedger. Calling Monday to find out being commercial client he probably go with a new hedger.

[bgsengine]

Tests perform. Compression >120 psi


Then AVB suggested I had top of the cylinder stroke damage. Darn it if he wasn't right. Slap worn out. Must have been losing all compression right the TDC of the stroke.

Hmm.. Seems hard to believe you were able to get 120 PSI , HOWEVER, knowing Echo, 120 PSI is the absolute minimum bare bottom end.

I bet you could have gotten it to fire on a shot of carb cleaner (not the "starting fluid" type... I used a brand called Johnson's, and while it can still wash away film of 2-stroke oil, one shot of carb cleaner isn't gonna kill anything.)

But yeah. good reminder that even when everything seems to test out just fine, it is useful to consider the Min-Max values of specifications and think what if you adjusted the test result up or down 10% or so...

[KE4AVB]

The reason I suggested the wear is that I have several Stihl chainsaws to do the same thing. Every one were cause top of the stroke cylinder damage. Just proves that even good tests can be thrown off by such wear.

And I figure if the engine can't start on what it is meant to start on there is no real purpose than a confirmation test. But I haven't had a can of starter fluid in my shop in over 10 years now. Sorta like not having a can of carburetor cleaner since 2014 when I went to using USC units.

[bgsengine]

Sorta like not having a can of carburetor cleaner since 2014 when I went to using USC units.

Yeah. I rarely used Carb cleaner all that much any more *for CARBS* after I got USC , but Carb cleaner can be very handy for many other things around the shop (Even in a wood shop - dissolve gummy residue off tools, Use it as a bug killer, scrub away grease stains, flush dust out of nooks and crannies, and more) So I always have a can of it around.