Power right up until full throttle - Stihl KM94-RC

[Mondo Mundo]

My first post on here, hopefully I've posted this in the right section. Would appreciate any help/point in the right direction.

Stihl KM94 RC, had it about 18 months, use it almost daily. Recently had new fuel filter, air filter, spark plug.

It starts easy enough and as I slowly increase the throttle the power increases smoothly until the last 20%, when it's almost at full power it just dies and I have to release the throttle to prevent it from stalling.

It's also flooding (I think), it stinks of fuel when the cord is pulled. And I've noticed that fuel is getting in the air filter.

I got the workshop manual for it and I've used it to the extent that I'm able! Nothing jumps out at me as being wrong, the carburetor was clean and all the gaskets were fine.

Thanks

 

[weesa20]

+1

would also check the fuel tank vent. Does it release pressure from the tank when you open the cap after it has stalled?

were OEM Stihl parts used?

also, was the carb tuned after the filters and plug were changed? Valve clearance checked in the last 50 hours?

sorry for more questions than answers

W

 

[Mondo Mundo]

99% sure there's no spark arrestor on this model.
Will check fuel tank vent now,
OEM used
Carb wasn't tuned, valve clearance not checked
No mention of valve clearance in the workshop manual.

This is from the manual regarding tuning the carb;

'10.5 Adjusting the Carburetor The new carburetors are tuned at the factory so that the engine receives an optimum fuel-air mixture in all environments and operating conditions. The high speed screw H and low speed screw L can only be adjusted with screwdriver 5910 890 2311. It is no longer necessary or possible for the user to change the settings of these adjusting screws. The user may adjust engine idle speed with the idle speed screw LA.'

Does this mean I cant adjust H/L?

 

[Mr.Navy]

KM94 is a true 2stroke = No valves, no valve clearance ;-)

 

[Mondo Mundo]

That explains its lack of mention in the manual

 

[weesa20]

I’ll go back to my FS/km 90/110/130 hole now...

 

[Mondo Mundo]

Its wet with fuel in the filter housing exactly around where the air goes into the carb. Is that likely a leaky carb? or would that be a symptom of too much fuel being jetted around?