2 stroke Husqvarna string trimmer wont start - (updated) to a happy ending

[oldnslo]

Remember the "help me fix this" sticky thread of days gone by?

Well, this "bought new" and used a good number of years, this model 128 has served me well, but after a few months of non use (not years), it failed to start. Thats typical for the non-weed-eating season.

Yep...it's got gas (as evidenced by a wet plug even after drying out), got spark, got good compression (120psi), muffler spark arrestor not clogged, plug is perfect (and shows spark when testing). No joy with direct fuel down the throat (or in plug hole), nor a shot of ether brings that joyful bark. Nothing!

It was powerful before. Never had mechanical issues, and a new carb kit was installed yesterday. I know those fuel diaphragms are finnicky when they start to harden. But the old one was not sketchy, but I replaced all the same.

What have I missed?

[john k]

Pull the muffler off, check the exhaust port for being plugged with carbon.  Been a problem with some chainsaws I got the oil mix a little heavy. Would also use a known good spark plug,  had 2 in recent years, look good, sparks good, wont fire under compression.  Try starting with the spark arrester completely removed.

[Crispycritter]

Pull the muffler off, check the exhaust port for being plugged with carbon.  Been a problem with some chainsaws I got the oil mix a little heavy. Would also use a known good spark plug,  had 2 in recent years, look good, sparks good, wont fire under compression.  Try starting with the spark arrester completely removed.

x2.......might just be a faulty sparkplug

[ron350]

If the trimmer has a primer bulb can you pump enough gas to flood the piston and spark plug?

 Went through the same thing last month with my old Weedeater. I pumped in so much gas the spark plug was soaked so I rotated two spark plugs each time I tried to start it. I would pull out the wet spark plug and spray it with starting fluid and then put in the plug that was dry after the starter fluid evaporated.

Finally got it to crank after swapping spark plugs several times an cranking and cranking.

I hope you get yours sorted out.

[jabberwoki]

Carb is blocked and or gaskets in the carb are toast.
Get a carb kit and rebuild it , blow out the jets, replace the fuel filter and clean the gas tank.
Pm me for my posting addy any beer will do. 
I strongly suggest you use real gas in you small equipment.

[DeadNutz]

After you get it running with the great suggestions on here, I recommend the use of Pri-G gas additive and fuel stabilizer. I have been using it for a couple of years and it keeps the gas fresh and really helps with 10% ethanol fuel. I only buy ethanol free gas for my Tacoma and small engines. It only takes 1/4oz to treat 5 gallons and all my cans get it. It is available in different quantities and I bought the bottle that will treat 512 gallons as it seemed like the best value for my needs. Also the easiest to use as you squeeze the bottle to fill the 1oz cup on top with the quantity you want.

I bought it off Amazon but watch the prices as they vary wildly.

https://priproducts.com/wp-content/uploads/2019/11/2015-PRI-G-Flyer.pdf

[slip knot]

quit using the ether on a 2 stroke. if it pops back thru the carb it will blow the crankcase seals and then you will have problems.

Have you checked your kill switch? I've had them break and ground the coils out. And always replace the hoses, anytime you have it apart.

I have a couple of Husqy saws and love them. Not indestructible but close. When I bought the pole saw they added a year to the warranty if you bought 6 bottles of their fuel. 3years + and it still smells like good gas.

[oldnslo]

Guys, all good suggestions, but please...do read the original post for the diagnosis thus far and actions taken.

Todays news is that by just looking at it, nothing has changed (another news flash, eh). HOWEVER, I did consider buying a running version just to get those weeds down to a manageable length and by doing so, I found the same model (a touch newer), not running for $15 on Offerup. A great donor machine at least. Bad news is that there is NO spark on that one, but the compression is the same at 120 for both.

My fuel is always fresh, I have other 2 strokes that keep the supply in use. The primer bulb is fine. I bought a supply of 10 of those a year ago.

I'll pull both apart, but at this point I'm thinking the timing has somehow gotten fubar'd on mine.

[oldnslo]

Progress:

The "parts" trimmer now has spark. I disassembled and checked the coil/magnet gap and ensured the coil ground was good. It now throws a spark (tho weak) when turned by a hand drill.

Both trimmers now have similar spark intensities, but I have not reassembled them yet.

In comparison to my Husq chain saw, that spark is more pronounced and more blue. I would presume smaller cc motors have smaller coils, and thus less spark potential (my theory).

 

[jabberwoki]

Is the plug wet after trying for a while?



"but please...do read the original post for the diagnosis thus far and actions taken "
Dooh ... yeah prolly a good idea 

[oldnslo]

Its all good Jabber. I amended the OP to describe a wet plug meaning fuel is being delivered. 

(edit) oh, and I found a retail anti theft tag mounted on the engine block (meaning NO access from a consumer POV). I guess that goes along with the unique part number on this 128L"D" on my parts trimmer, vs 128L on the one I bought new. I would presume D is for Home Depot, tho could be anyone. HD definitively creates their own part numbers on their items.

Sneaky bassstads!

[jabberwoki]

Do you think your getting too much fuel?

[TexasT]

How old is this gas mix you are attempting with. The gas today is measured in weeks without some type of stabil or other product in it.
Also those carbs have some pretty small offices in them. Gotta get em cleaned out so they will flow fuel through. Some good carb cleaner through there and some new soft parts should do you.

[slip knot]

I’ll have to ask the Husky dealer next time I’m in there if the D is for Homey Depot. I know the local John Deere dealer won’t touch a box store Johnny Deere. I bet the Husky dealers the same way.

[oldnslo]

Joy!

How? It happened on the first pull too!

What did I do? In my mind, nothing really. But I believe the root cause to be a weak spark.

The fine print:

After viewing many a Youtube vid on non-running small engines, I was target focused on the coil after all my original diagnostics. Yes, it did spark, and yes, when I hooked the crank shaft up to the drill and spun it with no plug, it did spark, but only consistently at higher drill rpms.

I wont bore you with the details of the coil DVOM measurement (or trying to get the specs...fail!), but I had similar ohm specs to compare and soldiered on. I reset the coil/magnet gap (seemed ok at the onset), burnished the grounds and re-assembled.

Oh...in the course of 100% disassembly, it got detailed to within an inch of its life, and I clear-coated over the fast fading Husky orange and rapidly starting to produce those wonderful fiberglass mold-casting splinters (from too much AZ sun), and it now is brighter, cleaner and tad bit shiny. Kinda like polishing a turd.

Well, I burned through a whole tank of gas just now and I'm pretty sure my neighbors will rest easier with less weeds in the back 40.

I know my tractors appreciate being discovered again.