spec450

My turnigy 52 overbore will only run if the screw holding the diaphragm plate is loose, to the point that it leaks while it runs. If you tighten screw down to stop the leak the diaphragm stops pumping fuel. What can i do to stop this? In the specs it says the carb is a (japanese walbro)<input type="hidden" id="gwProxy"></input><input type="hidden" id="jsProxy" onclick="if(typeof(jsCall)=='function'){jsCall();}else{setT imeout('jsCall()',500);}" />

All Day Dan

My Feedback: (5)

You may have the diaphragms and gaskets in the wrong position. On the side with the four screws, the gasket goes on the carb body side. On the side with the single screw, the gasket should be on the cover side. Check out the exploded view for your carb. Dan.
http://wem.walbro.com/walbro/group2.asp?FamilyName=WT

spec450

Today i went to the local lawnmower shop and got a rebuild kit for the carb. After installing it, the engine fired right up and ran great. After shutting it off and starting it again, The engine will only idle and wont advance through the rpm range at all. After numerous needle adjustments and the same crappy results im not at a loss It doesn't seem to want to draw more fuel as the throttle is advanced forward. I can watch a small bubble in the fuel line and it doesn't get drawn towards the carb at all<input id="gwProxy" type="hidden"></input><input jscode="leoInternalChangeDone()" onclick="if(typeof(jsCall)=='function'){jsCall();}else{setT imeout('jsCall()',500);}" id="jsProxy" type="hidden"/>

All Day Dan

My Feedback: (5)

spec, you want to make sure that the four screws holding on the diaphragm cover are not too tight. It's very easy to crush the gasket. That would push the diaphragm too close to the metering needle lever. While you're in there, check the metering needle for proper operation. Remove the pump cover. That's the one with the single screw and make sure the screen is clean. I use a can of contact cleaner and computer dusting air to clean and blow out the passages in the carb. It's worth a try. Do you know anything about the reeds? Take a look at them. Dan.

spec450

I took the carb down to the lawnmower shop and showed it to the guy. He took off the diaphragm cover and the cover witht he single screw you mentioned. He said it looked like a brand new carb on the inside. The screen was also clean. A problem i was having was when that "single screw" holding that plate on was too tight it wouldnt draw fuel. It would only draw fuel if it was semi loose. Only bad thing about that is it leaked while it was running.<input id="gwProxy" type="hidden"></input><input jscode="leoInternalChangeDone()" onclick="if(typeof(jsCall)=='function'){jsCall();}else{setT imeout('jsCall()',500);}" id="jsProxy" type="hidden"/>

All Day Dan

My Feedback: (5)

spec, if your engine is the one with side induction, then you don't have to worry about any reeds being the problem. Inspect the carburator isolator block and its gasket. Make sure all the holes line up and the passages are clear. If they look good try changing the carb. My Brison 3.2s use Walbro WT-76A and B carbs. They cost about $50. Dan.

spec450

Im going to tear the plane down and check the fuel tank as a last resort. If nothing presents itself in there then im going to replace the carb<input id="gwProxy" type="hidden"></input><input jscode="leoInternalChangeDone()" onclick="if(typeof(jsCall)=='function'){jsCall();}else{setT imeout('jsCall()',500);}" id="jsProxy" type="hidden"/>