# Stihl BG-75 Blower surging at WOT



## geogrubb (Jul 28, 2006)

Ok, oh great wizards of small combustion engines, I have a problem that really has me confused. It will not run at full throttle. This is a Sthil FG75 Blower with a Zama C1Q carb, the carb does not have a H and L adjustment screws, only the single Main Fuel Adjustment screw. It uses and RB-66 rebuild kit. When I received the blower it had old fuel, I put in new fuel, I would start but not stay running, it would spit, sputter and eventuall die. Since then, I carb disassembled and cleaned with spray carb cleaner and brake parts cleaner in all available holes cracks and crevases(the Zama website says not to soak in dip cleaner), I also didn't use a high pressure hose to blow through the holes only the carb cleaner which was Berryman B-12 Chentool. A carb rebuild kit was installed(RB-66), attention was paid to gasket,diaphragm sequence etc. and all that stuff. Fuel lines were flushed, filter/fuel pickup checked and clean. It started but would not go to full throttle. I ran 1/4 tank of fuel with heavy concentration of Chevron Chemtron Fuel System Cleaner at idle, removed muffler, burned all the oily gunk from the muffler, the piston, rings and cylinder walls were spotless. Now it will start first pull and idle but will bog and surge as I give it throttle. I actually got it to full throttle while playing with the throttle and choke at the same time, then when at full throttle I removed the choke and it remained a full throttle until I released the throttle(5 min) then it was back to the bogging. I did not remove the welch plug. That's as detail as I can get, sorry for being so long winded. Have a nice day. Geo


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## repair_guy (May 9, 2004)

Well Geo,sounds to me that you have the mettering lever set too low,or the inlet screen is restricting the fuel flow.


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## geogrubb (Jul 28, 2006)

repair guy
I checked it but will check again it says .012 but I didnt use a Zama tool. I'm going into it again but am going to soak for 20 min and use high pressure hose. The darn oil filler plug broke on my compresson and am waiting for a new one. I will post the results when available. Have a nice day. Geo


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