not sure where to post this one (mods feel free to move it).

The last little while when I've used my brushcutter (Kawasaki KBS27A) it's been difficult to start, and feels slightly down on power. Originally it would start 1 or 2 pulls, now it's 6-10 or even more.

Today I
- took it apart and cleaned it up (there was a fair bit of oil grunge on it)
- Took the exhaust off and blew a bunch of yuck out of it with the compressed air
- Took off the carbi and blew it out.
- Took the diaphragm off the carb to inspect thinking that this was my main cause for issues - thinking there was a hole in it. But no visible holes. Would it be possible that it's just stretched too much?
- put it back together

It did start a little easier, or maybe I'm just getting used to how poorly it starts. I gave it a little bit of time to warm up, but seems to have a slight flat spot? it's a non-adjustable carb as far as I can tell.

Is it worth changing the diaphragm?

It's had a new spark plug - was my first port of call probably 6 months ago.