Husqvarna power cutter model k960 s n 08 2100025

FIRST TIME EVER USED IT ? 6.5h ENGINE HERE.
got spark, THIS IS FIRST, using fresh plug to test.
got fuel? or is it super old fuel.
canT burn gas , lacking spark ,
the engine may have compression release just like huge single cylinder motor cycles have, and can fail. but just harder to start failed.
ASK MAKER FOR HELP
TOP CAUSES (BY ACTUAL USAGE FAILURES)
SO THIS TOOL SITS LONG TIME UNUSED? NOT TOLD
BAD OLD FUEL AND FILTERS AND CARB. DIRTY.
ENGINE IS 2CYCLE , GAS AND 40:1 OIL MIX OR PER MANUAL.
FUEL FILTER PACKED,
AIR FILTER PACKED
spark plug fouled, put in new. and gap it.

and this.EASYSTART SYSTEM.
The engine and starter are designed to ensure quick and
easy starting of the machine. Reduces the pull resistance
in the starter cord by up to 40%. (Reduces the
compression during starting

SEE PAGE 6
https://www.lsengineers.co.uk/media/advice_centre/Husqvarna/Power-Cutters/operators-manual-k970.pdf

SEE PARTS.
https://www.husqvarnaconstruction.com/us/power-cutters/k970/?article=967348001

Try cleanin the spark plug or even replacing it

You state you put too much oil in the cutter. then you state it uses straight gas. All the cutters I ever used had a mix of 2 cycle oil and gas. Usually when you place too much oil in the mixture it fouls the spark plug and could cause carbon build up. If the plug has oil on it it will never ignite. Do not put straight gas in the fuel to try to burn off the oil you will only make matters worse. Clean the plug, drain your fuel and start from scratch. If it still fails to start, you need to bing it in to a small engire repair shop. Good Luck!!

If it has spark and fuel then it may be worn, causing low compression and too weak to start. .

There is a simple test you should do on this unit. first remove engine cover, then remove spark plug, then take soapy water and spray it around the base of the cylinder where it meets the crank case, if you have compressed air and a air gun, shoot air through spark plug hole and watch for bubbles around base of cylinder. be careful to only shoot very low pressure into unit. if you see bubbles there is an air leak, this is not repairable. new unit.

A work around would be to remove the thread cutter mechanism completely. You can manually cut the top thread when spool changes are reqiired and would only have to deal with the bobbin thread when the hoop is removed. Moreover, I suspect when the cutter mechanism is removed the source of the problem will reveal itself. Depends on how skilled you are whether you tackle this yourself or take it to a sewing machine repair person. I suggest the latter.

husqvarna model 125b weed trimmer what spark plug do i use manual says rcj-6y in technical data and rcj-8y in monthly maint. ????

You need a new blade in the cutter. It is a simple repair job, but needs to go to the repairman for it to be done.

Check the model number all I have been able to come up with is a 235R brush cutter. I will be going by a dealer tomorrow for some parts I will ask him.
Please let me know, thru the comments section.
Good day.

What does your manual say?
If the 1634 is anything like the 1600 I don't think you can disengage it. I have the book for the 1600 and there is nothing mentioned about disengaging -- only changing the blades. Some models are like that. You might join the White serger group and ask the members there..
http://groups.yahoo.com/group/white_model_sergers
Someone may have an answer or a way around it.

Otherwise, all I can suggest is to call or go to a Joann's or a Husqvarna Viking sewing machine dealer and ask them. Alternatively, a sew and vac repair shop may be able to assist.