Partner k650 active II. Non starter

[Jonny Vee]

Got from an auction a Disc cutter k650 to keep as spare in case some stihl need service.

It started at first pull and idling very well but not accelerating. I cleaned up carburetor and put new gasket and diaphragm.

It started again at first full and seemed to accelerate very well than stopped and won't start again.

Spark plug get wet after few pull and end of story no way to start it

What could be wrong?

 

[Burnerman]

Not the most common of machines, but first I'd take the plug out, up end the machine so the plug hole is as low as it can be and crank it over - just to clear away any excess fuel before trying again.
Next, check the decompressor valve for leak by.....limited compression means no go with these.
John

 

[Jonny Vee]

John,

Cleaned up decompression valve.

What I see here the carburetor keeps filling of fuel even if not trying to cranck.

Removed all fuel. Cranked upside down few time. Tried to start and it started at second pull for few second as no fuel on the tank.

What's the issue. Carburetor related?

 

[Burnerman]

For sure, it does sound like the engine is getting a deluge of fuel.
After cranking the thing with the plug out, try starting without any choke, but always on full throttle. As I've mentioned before, taking the exhaust off and looking up the port for scratches can give you a pretty good idea of what condition the motor is in.
See if you can get a cheap replacement carb - often they are cheaper than a diaphragm set which is crazy!
Naturally enough, we don't know why the machine was in the auction in the first place.......!
John

 

[Jonny Vee]

For sure, it does sound like the engine is getting a deluge of fuel.
After cranking the thing with the plug out, try starting without any choke, but always on full throttle. As I've mentioned before, taking the exhaust off and looking up the port for scratches can give you a pretty good idea of what condition the motor is in.
See if you can get a cheap replacement carb - often they are cheaper than a diaphragm set which is crazy!
Naturally enough, we don't know why the machine was in the auction in the first place.......!
John

Strange thing is that I have replaced the diaphragm and other bits but keeps flooding. Is there anything else I can check on carburetor?

We don't know the reason of the sale but I saw loads of them maybe coming from some contractor that have renewed machines. Who know. Seems I good condition and start after carburetor is clean but not sure why is floading.

 

[Burnerman]

I’d recommend you take out the needle valve to check, see that the return spring is in place and the diaphragm that operates it ( the one with the round metal disc) is in good condition.
I have a device that measures the vacuum inside the carb, and also pressurises it to make the needle valve open.
Often replacement carbs are the way to go if faults aren’t obvious.
John

 

[Jonny Vee]

I’d recommend you take out the needle valve to check, see that the return spring is in place and the diaphragm that operates it ( the one with the round metal disc) is in good condition.
I have a device that measures the vacuum inside the carb, and also pressurises it to make the needle valve open.
Often replacement carbs are the way to go if faults aren’t obvious.
John

Issue was on the diaphragm which slipped from the needle valve and was putting pressure without pulling it and basically was flooding the carb.

Start fine now.

For a fine tuning I currently set up H and L at 1 1/4 but seems still not the best set up as no fast response when accelerating but taking few second to rev up

Any tips on the adjustment?

Thanks

 

[Burnerman]

When you are trying to accelerate the machine, concentrate on the L screw......I think you are running a little rich so try turning it clockwise to 3/4 or 1 turn.
For the H screw, its slightly more difficult as the machine needs to be under load....when it is running hard it should rev up very quickly and then start to ‘four stroke’, I.e tend to misfire, which will correct itself when the machine is cutting.
I don’t think the H adjustment is far off, maybe turn clockwise a little. If you over do this one, the saw loses power.
John