Mixture problem?

[BobbyDee]

My saw starts then dies as soon as I touch the throttle. It'll do this until I can rev the bejabers out of it for a second or 2 and then it behaves itself mostly, but I don't particularly like to rev it high when it's cold so is this a too lean mixture problem which I can sort myself?

[woody paul]

What make and model would help.

[traktorz]

Fuel problems are actually quite common, especially during and after the winter season. Water through snow and condensation due to temp variations causing the saws to run with difficulties. Replace with fresh fuel, ideally with Aspen.

[BobbyDee]

What make and model would help.

Hitachi(Tanaka) CS45EL with Walbro WT-497A carb.

[spudulike]

If it is dying as soon as the throttle is touched it may be that the L screw needs a tweak anticlockwise to richen up the idle. If you can get high revs out of it by feathering or pumping the throttle then the high speed needle is probably OK.

 

The L screw sorts out saw performance from idle up to around 4500rpm and then the H screw kicks in. The fact you can get the saw to rev out means the H screw is probably OK.

 

Often these small engines leave the factory pretty lean and then stop like this. You may need a specific screwdriver to adjust the screw - splined or "D" shape.

[GardenKit]

Everything that Spud says, BUT, before fiddling with screws just ensure that the petrol is fresh and mixed with oil at the correct ratio of 50:1 or you may try to tune out problems that do not exist.

 

The adjuster screws are slotted, but have limiting caps, but to be honest, these 'old school' saws tend not to be as lean 'out of the box' as the newer design low emission saws.

[BobbyDee]

Thanks for the input. Have tweaked the L screw as suggested and it seems to have done the trick.