K 970 Cut off saw service information.

[bertsmobile1]

This saw has been busting my balls for a week.
Owners rings 4 times a day chasing it.
Shame he did not spend the same time servicing it.
It is fitted with a Walbro RWJ-5 carb for which I can find no service information.

When I got it it would start easy & run no more then 3/4 throttle
It just cut out, no lean running speed increase, no 4 stroking rich indication, it just cut off.
Run the carb through the ultrasound checked for flow through all the orifices working well including all 3 of the start / idle holes.

Owner had the idle screw right in till the throttle lever was level with the bottom of the screwdriver slot so assumed it was idleing on the high speed jet.
Put a kit through it replaced every thing except the needle as it had a Vitton tipped needle & the genuine walbro kit comes with a solid brass brass one.
Needle holds pressure & unseats when I blow air through the venturi so it appears to be functioning normally.

My carb repair kit does not have needle height for a RWJ marked on it so I have no idea what the needle height should be.
I also have no idea what factory start settings on the H & L jets should be and have just about worn out the elbow starting the thing.
walbro's web site does not list the RWJ series let alone have any service info and Husqvarna only have parts books & owners manuals which all say "fixed jets "
When I got it it was H 1.25 & L 0.75 turns but now it is ( hopefully ) clean those don't work.
It was on a concrete saw , muffler is clean, compression is good , cylinder & piston are clean brain is just about exhausted.

Any one have any ideas ?

 

[BlazNT]

Sounds like you have done everything plus some.
Just remember that even though it was running when it was brought in it may have had something break after you started working on it. Test for spark and air leakage after the carb. Make sure valves are moving like they are suposed to. I am just trying to think of all the stuff you tell everyone else to do.
My mentor always started with 1 1/2 turn out on carb adjustment. This was 40 years ago but it is where I always start.

 

[bertsmobile1]

Tar Blaz,
Starter by using the settings it came in with which have to be wrong.
Got a flashy plug cap on it which I use with hand helds cause the lead is usually too short for my normal plug tester.
These things are big engines with a very over square engine .
Down here the replacement carb is $ 295 ( Aus ) and a weeks wait because Husqvarna have a min parts order so I have to chase a dozen dealers to find who is about to place an order.
Stihl started this stupidity, MTD followed suit and now Husky has joined the band wagon.

Just a bitch because if the metering needle is wrong, nothing else will work properly and numb nuts here forgot to measure it before I pulled the carb down but as it is the original needle I have assumed it to be correct.
Original owner says he has never toughed it ( pure BS ) and no information.

Gripskies are the agent for Walbro down here but they have no technical information that is not already on Walbros web site.
Husqvarna say it has fixed jets but their IPL shows adjustable ones and Walbro list the jets as parts.

Normally it would sit in the too hard bin ( gets bigger every week ) but the owners is becoming a pest. ( which he will pay for if I can ever get it running properly ).

 

[Kenworth903]

Hi guys,
Any updates on the k970s?
I service these tools and I’m trying to get any tips or updates on how to get them running properly.
Cheers

 

[bertsmobile1]

Because the tank failed pressure testing
New breather $ 95
because the spark was irregular
New ignition module $ 195
Because 3 hours in the ultrasound & 2 rebuild kits could not stop it failing lean
New carb $ 142
Because at 95psi the compression was 19% down on the calculated value ( no information available to me )
Rings, bearings & crank seals $ 75
Labour $ 360 ( @ $ 1.50 /hr for actual ,time spent, ignoring research )

And it is still randomly cuts out after a few minutes then won't start, followed by running through a full tank of fuel without missing a beat.
It is sitting in the naughty corner at the moment & I think the customer has given up & bought a new saw.

None of the Authorised Husqvarna dealers will service these unless brought in by the original purchaser and several of the techs who give me a hand occasionally told me they instructed their dealers not to sell them because they could not service them.

If you have any service information then I am all ears, I hate being defeated but this has got me well & truely beaten.