dick747 Posted August 20, 2014 Report Share Posted August 20, 2014 CTLS was hard to start today. When it finally started it ran very rough like it was flooded. Shut down and pushed back into the hanger. Then I noticed fuel dripping onto the hanger floor. It was coming from the drain from the airbox. I pulled the right carb loose and had a lot of fuel run out. Removed the bowl and checked the floats. They looked fine so I filled the bowl and both floats rose up the same. Reinstalled the bowl and carb and started the engine. Everything was OK. Must have been a stuck float but why did it happen. The airplane is one hour out of an annual during which the bowls were checked for debris and new gaskets installed. Question is should I fly the airplane or is further maintenance required? Link to comment Share on other sites More sharing options...
Roger Lee Posted August 20, 2014 Report Share Posted August 20, 2014 Leave the cowl off and have someone run the engine from 3000-4000 rpm and take a look at the floats. If they don't leak then fly. If fuel pours out, find the problem. Stuck floats can happen and some times tapping on the bowl with a screwdriver releases them. Link to comment Share on other sites More sharing options...
dick747 Posted August 20, 2014 Author Report Share Posted August 20, 2014 Alter checking the floats I reassembled and ran it up to 4000 rpm. Ran fine and no leaks noticed. Will fly tomorrow and stay in the pattern for a while to make sure all is OK. Link to comment Share on other sites More sharing options...
Doug G. Posted August 21, 2014 Report Share Posted August 21, 2014 Roger, one thing I have noticed is that it is somewhat easy to get the carb bowls slightly crooked and not sealed. Could this have been the issue? Link to comment Share on other sites More sharing options...
Roger Lee Posted August 21, 2014 Report Share Posted August 21, 2014 Possibly. Link to comment Share on other sites More sharing options...
Tom Baker Posted August 21, 2014 Report Share Posted August 21, 2014 I have also seen some issues with the new fuel pumps pressure pushing the float needles open, if the are not holding well. Link to comment Share on other sites More sharing options...
FlyRatz Posted August 21, 2014 Report Share Posted August 21, 2014 Hi, to check the float needles I use the following technique: 1. Separate the carb from the engine. 2. Empty the fuel chamber. 3. Connect a open ended hose to the fuel-in connection point. You will need such a connector: 4. At the open end of your hose, connect a manual vacuum pump like this one: 5. Turn the carb upside down. 6. Apply a small amount of vacuum (not too much!) 7. Check, the vacuum remains stable at least for 10 seconds even if you turn the carb back to upside up carefully. If this procedure fails, the valve needles must be replaced. I buy them at a sparepart dealer for oldtimer BMW-Bikes. They are much cheaper there.... Happy landings Markus Link to comment Share on other sites More sharing options...
Runtoeat Posted August 22, 2014 Report Share Posted August 22, 2014 Markus, is there a Bing part no. for the float needle you buy at the vintage BMW parts store? Link to comment Share on other sites More sharing options...
FlyRatz Posted August 22, 2014 Report Share Posted August 22, 2014 Hi Dick, the Bing-Number is 47 968. Last time I bought it direct at Bing. Recently they changed policy and do not sell to privates any more. So you need to find a Bing-Dealer. I would suggest to ask bingcarburetor.com. Good Luck Markus Link to comment Share on other sites More sharing options...
Tom Baker Posted August 22, 2014 Report Share Posted August 22, 2014 Actually Rotax has a procedure for testing the needle in the manual. They call for pressure rather than suction. When held upside down the needle should hold 7 pounds of pressure without leaking. You can put a little light oil around the needle and watch for bubbles. Be careful not to add the pressure to quickly or go higher than 7 pounds, because it will splash oil in your face. Don't ask how I know. You will need the same banjo fitting, and I used my oil pressure purge regulator. Link to comment Share on other sites More sharing options...
Anticept Posted August 23, 2014 Report Share Posted August 23, 2014 3. Connect a open ended hose to the fuel-in connection point. You will need such a connector: This is called a "ring nipple". Unfortunately google searches are a little NSFW (not safe for work) if you go looking for them, so it helps to put in "ring nipple banjo connector". Link to comment Share on other sites More sharing options...
Tom Baker Posted August 23, 2014 Report Share Posted August 23, 2014 Just "Banjo fitting" will get you what you need. Link to comment Share on other sites More sharing options...
Doug G. Posted August 23, 2014 Report Share Posted August 23, 2014 Yeah, if you search for "nipple ring" you will be getting a lot of things that won't fit the purpose. Link to comment Share on other sites More sharing options...
207WF Posted August 28, 2014 Report Share Posted August 28, 2014 I had this same thing happen once on a cross-country stop. Calling my mechanic for help, he suggested taking the overflow hoses off the sides of the carbs, with the float bowl removed, and blowing shop air in there to dislodge any crud that might have blocked the valve that the float normally shuts off when the bowl is full. That worked. WF Link to comment Share on other sites More sharing options...
FlyRatz Posted August 28, 2014 Report Share Posted August 28, 2014 I had this same thing happen once on a cross-country stop. Calling my mechanic for help, he suggested taking the overflow hoses off the sides of the carbs, with the float bowl removed, and blowing shop air in there to dislodge any crud that might have blocked the valve that the float normally shuts off when the bowl is full. That worked. WF Strange! The overflow bore does not connect to the needle valve. Instead it connects to the area above the fuel level in the fuel chamber. If it helped, he did a great job anyway. Greetz Markus Link to comment Share on other sites More sharing options...
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