Wanted to cut out on landing

[Pearson]

Re: Wanted to cut out on landing

Well guys,
Had an IA at the airport take a look see. I adjusted it a tad and really never got it running "right" . IA says I can adjust till doomsday and it may run fine one flight and be off the next. Starting to get weepy around some of the gaskets, so letting some fuel out , some air in. He recommends I trade mine in for a rebuilt one or have mine sent off and rebuilt, as I would get a warranty for a carb shop. Being President of "The Poor Guys That Have An Airplane Club", what should I expect to have to spend? Will I have to sell one of the children? LOL IA says he would be glad to supervise the taking the carb off and putting one back on.

Patrick,

Rebuilding the carburetor seems a bit like a knee jerk reaction to me. That may fix your problem, if the problem is with the carburetor. But as someone else suggested, it could be a leaky primer. It could also be leaking intake tubes, sticking valves, or any of several other possibilities. I would certainly not rebuild a carburetor just because there was a little fuel stain around the gaskets. Someone with the mechanical skills can tighten up the screws, or even replace the gaskets. While they have it apart you can have them check the float level and the functionality of the needle and seat.

When troubleshooting problems associated with the carburetor I have found it best to find the answers to two basic questions. First, is an adequate fuel supply reaching the carburetor. Second, is the engine running too rich or too lean?

Please note - I AM NOT A CERTIFIED A&P MECHANIC.

Before you pay someone to rebuild your carburetor, this is what I would do if my plane had your symptoms. I would take Dennis' advice and eliminate the primer leaking as a possibility. Either remove the line and block it off, or replace the O rings. Then I would tighten up all the clamps on the intake tubes. I would also remove the fuel line at the carburetor, turn the fuel on and see if you have a good clean steady flow into a bucket. Even if you do, you may want to take the gascolator apart and clean the screen at the top. If all of that looks good, I would have a mechanic knowledgeable on your model of carburetor split it open to check the float level and working of the needle and seat. The reason I suggested in an earlier post to have someone watch for smoke while you fly the pattern was to answer the question of is it running rich or lean.

That is what I would do. Maybe some of the older heads on here will chime in soon with some other ideas. I can tell you from experience when trouble shooting many other engine problems; don't jump on the first thing that comes to mind, and always look for the simplest solution.

[M Towsley]

Re: Wanted to cut out on landing

I had these guys do mine and were reasonably priced. Link: http://kpsairmotive.com/

I cannot remember how much I paid, at the moment.

[paddydix]

Re: Wanted to cut out on landing

Well guys,
Had an IA at the airport take a look see. I adjusted it a tad and really never got it running "right" . IA says I can adjust till doomsday and it may run fine one flight and be off the next. Starting to get weepy around some of the gaskets, so letting some fuel out , some air in. He recommends I trade mine in for a rebuilt one or have mine sent off and rebuilt, as I would get a warranty for a carb shop. Being President of "The Poor Guys That Have An Airplane Club", what should I expect to have to spend? Will I have to sell one of the children? LOL IA says he would be glad to supervise the taking the carb off and putting one back on.

[N95334]

Re: Wanted to cut out on landing

Had same problem where it would quit on landing roll out. Replaced all the O rings in primer and it helped.

[paddydix]

Re: Wanted to cut out on landing

Mike, I do believe that is the road to go down. Going to take the cowlings off and really check intake and such for signs of air leaks. If that all looks good then adjusting the idle mixture a tad.

[mike lutz]

Re: Wanted to cut out on landing

Try opening the idle mixture needle valve one half turn,See if that helps.500 rpm at idle is good.

[paddydix]

Re: Wanted to cut out on landing

Good point! Before I took her flying, I let her idle at different rpms on the ground. At 500 , she seemed to just not be running to peppy ( hard to describe it), at 550, improved( like an OK I am ready!), 600 same and on up to 1700 rpm's. Once on the ground I gave it throttle to about 1500 from idle and she stumbled a bit,...but only the one time. I did that about 10 times as I didn't like the stumble,..and sure was not going to fly her if I thought she was going to do that on climb. She only did it that one time on the ground, and she preformed nicely on climb out. When coming back in for landing, I did not get the clack of the impulse,...engine was running , just not great at idle. Wife is printing off a carb manual at work today, and I plan on taking the cowls off Sunday and checking the intakes and carb seat to make sure I don't have any air leaks there. If I find nothing there ,...befuddling! LOL RPM at idle to low? All the way out I am idle at 500. Since the air filter helped ....mixture?

[3Dreaming]

Re: Wanted to cut out on landing

The filter wouldn't help your problem on landing. When landing you have carb heat on and the filter is not being used.

[paddydix]

Re: Wanted to cut out on landing

Ok, I got to do a little flying. Air filter helped! I had noticed a little hard to stay running at idle when I propped it, would die before I could get in the seat. I just attributed it to the air getting cooler. Today, I propped it , it kept running and gave me time to enter the airplane . Did fine on take offs,...did a lot better on landings. It did not start to cut out,...but something just tells me it could run better if rpm was upped alittle. 500 is where it is, thinking maybe 550 would run a bit better ? In flight I ran it at 1000 and 750 and a few other areas of low rpms and it seemed to be fine with not even a hint of wanting to cut out on me.

[M Towsley]

Re: Wanted to cut out on landing

Unless you fly through a lot of dirt and bugs I wouldn't think so. Just to keep in-mind, when my engine cut out I could advance the throttle, and once it got out of the idle circuit, it ran fine, (basically because the engine wasn't pulling fuel through the little hole that was clogged). I carried power until I was well over the runway and pulled it back, where it quit. If it does this don't let the engine get too slow or it will not keep running no matter where the throttle is at. The first time it happened I did not realize it until I heard the impulse clacking. You can actually feel the the carb going from high range to the low range, even when it is running fine. You really know it when that port is plugged.

[paddydix]

Re: Wanted to cut out on landing

Have not had the greatest weather for a few days. Trying to clear up but still MVFR for low clouds. Hope it clears some this afternoon. My air filter was changed in May , but have been thinking maybe it has something to do with it, definitely one of the most simple things to check out.

[DPKII]

Re: Wanted to cut out on landing

Does sound like your idle mixture is off for some reason. Carb blockage is a possibility as suggested but don't rule out a leaky primer as mentioned or a vacume leak in the intake.

Thanks,
David

[M Towsley]

Re: Wanted to cut out on landing

Patrick,

Chances are having whatever may have blocked the orifice work its way out is slim. Those holes are tiny so the carb will have to come off. While I had mine off I sent it off and had it gone over to make sure everything was ok. These are pretty simple carbs, but I did not want to experience that again. Turns out mine was a little on the lean side. It has, (knock on wood), run flawlessly ever since. I had mine gone through by KPS Airmotive.

[Howard Wilson]

Re: Wanted to cut out on landing

I think Marty and Richard are on to it with the blockage. Had a problem with mine where it would idle and run up fine but when the tail came up on take off it would almost quit and run rough. Turned out to be a bunch of flaky crud in the gascolator screen. Not quite your issue but a bad batch of gas can clog it up..... h

[paddydix]

Re: Wanted to cut out on landing

I thought about the difference in temps, air was cooler today than it has been . Then I thought, well no changes in any settings have been made since I bought it in Oct. , and I was flying it in the cold of winter, and then all summer ....and temp did not seem to bother it. Larry I have one of the original primers, it was in and locked. (I get tickled at that old primer, seems like you pull it all the way out and push in and you put a half gallon of fuel in! LOL) I am leaning toward some kind of obstruction in the idle circuit. I hope I can get lucky and whatever it is works itself out of there ! I'll let you guys know how the pattern test flights go .