Stihl 4mix

[hanz63]

This is my personal trimmer that I could use some help with. It is an FS110, circa 2004. Hour wise she gets run ~ 5 or so hours a year. But gets used with a knarly blade for much of that. The story has always been the same. Use clear gas w/ Stihl synthetic 4 mix. Prime until I see mix in the primer bulb, then an extra 1.5 times, choke and it is running and ready to go in 2 pulls. My wife uses it too and complained about it being a bugger to start, but got it going and ran it until it ran out of fuel. I saw the primer was splitting and thought I'd replace that and make up some fresh mix and swap the plug out. Took me 20 minutes to start it. Felt it kick a bit as I pulled the snot out of it, thought it best to adjust the valves which it needed and frankly I never did on this before. I ran it enough to know that the new mix made it through. Doesn't kick back, but wants to pop rather than to run up unless I baby it with the choke nearly closed. Once it is running, it runs great like it always has. What am I missing here?

[KE4AVB]

First check the muffler's spark arrester. They tends to clog with carbon.

If that not it then find out which Zama carburetor is on it. Since Zama will not sell the repair kit directly via distributorship channels anymore due Stihl orders you have two options. One is to buy a new carburetor from Stihl or if you are lucky get an aftermarket repair kit.

If your going with the new carburetor Stihl dealer will need to lookup the current part number as Stihl is constantly changing the carbs.

[Arkie]

Once you come up with a Zama carb number, the small zama number is usually on the side of the carb and may take a magnifying glass to get a read (or a carb model for that Stihl trimmer) I've had good luck using HIPA tune up kits for small 2 cycles.
You usually get a carb, filters, fuel hose, spark plug and carb tuning tool. (for around or less than $25)
You may have to order a carb jet adjusting tool if none in the HIPA kit. (You will need the tool)

You can usually get a clone Zama kit for less than $10 but it's a clone kit and toss up rolling the dice on clone kits. (some clone kits won't even have correct parts, close but no cigar)

If the tune up kit still has same results you might have a crank seal issue, especially if it has low idling problems.

[hanz63]

The muffler and screen are clean and good. Pondering the pop and extended cranking coupled with the normal running once it gets run up. Carb? Coil? Flipped a coin, ordered a coil. In the end, I probably should have ordered one of each... Will post how foolish this turned out.

[hanz63]

Coil fixed her up.