Tuning

[Al Mondz]

Hi Guys,

 

Is their a basic setting or a 'start point' for tuning a saw ? Mine is so messed up (no idea how that happened ) and have no idea where to start. Its Husqvarna, but advice on Stihl would be great too.

 

Regards,

 

Al

[TGB]

In short, yes. But it depends on what saw exactly. Models please, then Spudulike, Wisecobandit and Gardenkit will be along shortly.

[Ray1]

The basic setting for the majority of carbs is one turn out from fully seated. That should get your saw started then go from there.

[spudulike]

A very tough rule is one turn out from fully in on both screws but there are some exceptions.

 

If the saw has limit caps on the carb, the setting is different and with Stihls, generally on the side of the air box.

 

These settings are the starting point and whilst the H screw is generally pretty much on factory, I have found L screws to need + or - 1/4 turn on factory settings.

 

The H screw is the critical one and is always the screw furthest from the engine, lean it out too much and the saw will over-rev and will possibly seize.

[adw]

Tuning your saw is not to be taken on lightly, leaning the mixture on the high jet can result in over reving and seizure, the carb should not really lose its settings, things like blocked air filter, blocked fuel filter, and or air leaks will alter the carburation, you should not alter carb settings to compensate for these issues, all max revs should be checked with a taco, not by ear, you need the Husqvarna model for us to give the max factory rpm.

[Al Mondz]

Thanks for the advice guys. Its a Husqvarna T435 top handle. Daft question but 'fully seated' , would that be turned in all the way to the right or left ?

[adw]

The screws are fuel screws not air, so turning then clockwise will reduce the fuel flow and lean the mixture, this model is actually a Zenoa machine badged engineered Husqvarna.

[Eddy_t]

Fully seated is wound all the way in (right), the screws are then turned anti-clockwise to richen (add more fuel) the mixture. The factory defaults can be found in the manual. You need a tachometer to fine tune the saw

[GardenKit]

Fully seated is wound all the way in (right), the screws are then turned anti-clockwise to richen (add more fuel) the mixture. The factory defaults can be found in the manual. You need a tachometer to fine tune the saw

Exactly, but just remember to only wind then in very gently until they just stop. Do not force them all the way in or needle and seat damage can result

[Al Mondz]

All understood. There is also a much larger screw marked with a T on this particular saw. What is this for ?