Carb adjustment for easier starting?

[david newbie]

Some saws seem to take a lot of pulling, even after a carb rebuild. Is there any sort of general rule of thumb? I can usually adjust the low speed screw okay while it’s running, but I always wonder if a little leaner or richer would help it start easier. Asking this question while I’m working on a very low hour sexy Wild Thing I know there’s going to be a dumpster comment. I paid 80 total for the 3 saws

 

[oldguy]

I like to think a little richer on the low screw works best, then bring the idle screw up to get a clean idle, this for cold starting.

 

[SunburnedCock]

I have always tuned idle for max rpm on a fully warmed up engine. I may slightly tweak for off idle response.

I also re-tune the screw between seasons, as it is heavily dependent on outside temperature

 

[John Lyngdal]

I'm in the slightly rich low speed jet camp, then set the high speed jet to compensate.

 

[altatim]

Never had an issue with a well tuned saw starting easily. Just make sure that the idle is set right and all should be good. Too rich on the L can cause fuel pooling which is an issue on its own.

 

[MacAttack]

I came to suggest a little more rich on the L adjustment and turn the idle up a little helps with cold starts.
With that said.... an old, stiff diaphragm in the carb will make it start hard too.

 

[huskihl]

You could compensate a little bit with the L screw and turn the idle screw up to compensate. But most of the gas comes through the H circuit straight through the brass nozzle when the choke is closed and throttle is open (high idle). Hard to justify opening up the high-speed needle though, just to get it started and then have to retune once it’s running. You likely have a stiff diaphragm or two and/or the needle lever is set too low. I would also check the fuel filter and fuel line

 

[stihltech]

When you have to fiddle with the carb a lot to get an easier start, it is time to look further. I would be doing a vacuum and pressure test.
Alternately, get a can of brake cleaner and spray around gaskets, seals, and any point where air might be sucked in. I bet you will find the idle change somewhere.
This is why in the shop I usually replace a carburetor. The results are immediate.
I realize on older saws it may not be an option. Recheck the inlet lever height and fuel lines. Don't forget the vent.
It is not getting enough fuel for a reason. And it usually is not adjustment.

 

[Jeekinz]

Pull the choke and give it a coupla slow primer pulls first. Dont just start yanking on a cold engine.

 

[Old2stroke]

Do a search on this forum on how to tune the saw and make sure the carb is adjusted right, then follow the right cold start procedure. If it has a primer bulb, pump it until you can feel fuel being squished through it, ignition on and choke FULLY closed, throttle SET TO FAST IDLE. Pull until it pops then open the choke but LEAVE THE THROTTLE SET AT FAST IDLE. A couple of pulls and it should start and run fast until you reset to normal idle. The Wild Thing has a button on the rear handle in front of the trigger lock-out lever to set fast idle. Don't know how the other saws achieve fast idle but they will all have it. If you try to start a cold saw with the throttle closed at the idle position, you are in for a LOT of pulling. If a saw doesn't have a primer bulb, expect to do more pulling to get it started then one with a primer.

 

[david newbie]

Thanks everyone. I got the wild thing starting nicely. Had to richen up the low speed and turn up the idle. Sold it to a fellow who planned on using it for a 20 minute job. I told him to wear thick gloves!!