Husqvarna 390 Questions.

[AVB]

This my first saw in the shop in this CC range, normally I work on under 60cc range.

What the normal max rpms for this saw. Currently it max is 7000 with 6800 hard into the cut.

It is 4 cycling very heavily. Just wondering if I have bad coil on my hands. I tried leaning the carburetor but never got a clean 2 cycle out it even with the H mixture set to minimum.

Just needing a little guidance on this one.


Edit: To me sounds more like it is missing but I have already tried a new plug.

 

[Frank bierce]

Shows max rpm at 9600.

 

[Termitebuffet]

When you say set to minimum, are the limiters removed ?

 

[RIDE-RED 350r]

Something is definitely off, that saw should be way higher than 7k no load.

 

[AVB]

When you say set to minimum, are the limiters removed ?

Has those spring limiters and yes I depressed them and turn them until the needles seat. Currently reset to 1-1/2 turns each.

Something is definitely off, that saw should be way higher than 7k no load.

That what i thinking too so it looks I might have another expensive coil bad. Had one on a 570 last year that similar except it would worse the hotter the coil got.

 

[RIDE-RED 350r]

1.5 turns each should definitely be safely rich, but if you tuned and could only get 7k that is screwy. Got another known good coil you can swap in to test?? Should be the same coil from 346 all the way to your 390.

 

[AVB]

According the IPL it is different but I do have 359 I just put in the spare parts pile due bust crankcase that runs. Supposedly it is a speed limited coil. Anyway I go out put the 359 and try it on the 390. Heck I might learn something new. Gone to try it out if nothing else it either be better or worse. If better then I know it is a bad coil.

 

[mdavlee]

Blue is limited. Black is unlimited

 

[AVB]

Thanks for the info about which limited and is not. I adding this info to inventory notes about the coils.

Well then it unlimited now. The 359 works but I needed to change out the high tension lead the 359 is too short.

Well at least I was on the right track as to what was wrong.

Again tnx for the replies to an old dumb tech.

 

[Chainsaw Jim]

Max rpm should be 13,000 no load.

I can think of a few things to check along the way to the coil. Carb, plugged exhaust, plugged filters, sheared flywheel key...

A limited coil won't limit it that low.

But all in all it's built the same as the 346, only bigger.

 

[AVB]

Max rpm should be 13,000 no load.

I can think of a few things to check along the way to the coil. Carb, plugged exhaust, plugged filters, sheared flywheel key...

A limited coil won't limit it that low.

But all in all it's built the same as the 346, only bigger.

Jim, I was just needing some reassurance that I was on the path. I didn't know that coils on several models were the same except for the leads so I can stock one for later.

All items listed was checked prior the post. That makes the second coil in less two years for the same customer. Of course it was two different saws but that still doesn't make him feel any better. Other other one was the 570.

 

[mdavlee]

Coil is lifetime warranty for original owner or was with Husqvarna

 

[Chainsaw Jim]

Toss a different coil at it and let's see what's going on.
Check valve check out ok? I'm used to seeing these symptoms when the carb is bad or needing rebuilt.

 

[AVB]

Repairs completed. Bad Coil.

Please close thread.