Yes, once you start fiddling it does get a little time consuming, but it's a good learning experience. I keep a modified 31cc Ryobi handy for rough tuning carbs. I also found that having a fuel tank on a stand with a long fuel line is nice to test the metering arm height/fuel flow. When the carb doesn't leak fuel with a 2'-3' pressure head and it pulls fuel with the choke set and engine "cranking" the metering arm is good to go. (YMMV) Then you can set the hi and low needles.I figure 30 - 60min to setup the carb, faster once you get the hang of it. Test motor is nice because you can keep carb on and only pull off 4 screws over metering diaphragm. I found that the Ryobi likes a little pipe especially when you get above 150 degrees duration on the exhaust otherwise it's impossible to tune. (It can run with the carb inlet plugged/choked because of exhaust reversion with an open exhaust)I bought a 10 pack of diaphragms for my walbros, but they are not an exact replacement for some of the carbs I have, so I got pretty good at tweaking.The carbs came from a pile I found at the local scrap yard, brought home about 30 assorted diaphragm carbs,