Stihl 026 - fuel leaking from exhaust

[spudulike]

take the air filter off, turn the saw on its side, fill the tank, look down the carb and put the fuel cap on. Does fuel piss through that little brass thing in the bore of the carb???

If it does - IT IS THE NEEDLE VALVE!!!

What a life

[TommyT]

I will do all the checks you have said when I get back to the saw later on. 
Don’t you think it strange if all three new needle valves We’re stuck open though?

 

Can anything have happened when I cleaned the three carbs with the ultrasonic cleaner. 
That’s the only new factor I have done with this particular rebuild?

 

Yes everything is airline blowed dry including the muffler. 

[TommyT]

Never looked down the carb for it to be leaking at that end. 

Will check that too

 

cheers for all this help

[ChrisNewport]

Three cleaned and re kitted carbs all doing the same thing points at wrong or faulty carb kits.

 

How have you set the metering arm? I'm guessing it's fully depressed when you've assembled the carbs.

[spudulike]

Pretty much the only way you will get lots of fuel in the engine is a stuck needle valve unless you are pulling it over forever with the choke on.

Three carbs faulty - yup, spooky but as we keep saying....needle valve. There were a number of carbs on these machines, some had a very short nipple on the diaphragm and some had a long one, one metering arm levels with the body of the carb, the other levels with the bottom of the diaphragm bowl.

Something tells me the needle valve has been set incorrectly, the US clean has made the needle valve stick on (shouldn't leave them in when cleaning) or the incorrect diaphragm has been fitted.

The tests I have banged on about should tell you if the carb isn't holding pressure and just understand that some of us do this for a living and as such, we have to hit the bulls eye first time, every time and also own a fair bit of experience between us!

How are Arboristsite doing on the issue?

[Khriss]

Poor Spud  (  i would have popped the beers round fr you at this point  ?)  K

[Wonky]

I think..... the op has put the diaphragm on the carb body and the gasket on the top,,,, thus pushing the needle valve open..

[spudulike]

I tend to give up and think Darwin has a point!

[bmp01]

44 minutes ago, spudulike said:

I tend to give up and think Darwin has a point!

I think Darwin gave up and moved on.

Not judging the poster of thread .... he might not be paying enough attention to what people say but he was working with some logic.

 

But yeah, in general, Darwin definitely has his hands tied with modern day safety .... shame really its not for the best, just means the human race gets progressively more stupid.

 

 

 

 

[ChrisNewport]

He's got it sorted, thanked everyone on other site. It was needle valve. I await my personal thanks for hitting the problem in the first reply.?