Eddie Cesnalis Posted July 16 Report Share Posted July 16 My 07 CTSW is running very well. This morning with 16 gallons aboard (fuel in both tanks) I was slipping on short final at idle and the engine and prop stopped. With the landing assured I concentrated on the dead stick and clearing the runway. It then started on the first blade with throttle at idle and is again running great. What should I be thinking? About a month ago I couldn't get full power for take off first thing in the morning two mornings in a row. WOT resulting in rough running at reduced RPM. This self cleared within a minute of static WOT and we cleaned float bowls. No more symptoms after that, there wasn't much debris in the float bowls so I'm no conviced one way or the other it was the issue. It's been a while since my carbs have been balanced. My A&P says he can balance but obviously isn't comfortable with it and he usually passes becase its running fine. What is likely to be the first symptom of too long without carb balance? Quote Link to comment Share on other sites More sharing options...
Anticept Posted July 16 Report Share Posted July 16 Roughness is the first sign, that seems to go away at different settings depending on the balance issue. If idle is balanced but the throttle swing isn't, it will get rougher in the mid settings and clear up at idle and full. If it's out of balance for idle, its rough at idle but clears up with a little throttle added. If it's rough at full power (any setting really but especially full), that's usually a fuel delivery issue and can be a whole slew of things, usually something with the carb jets plugging them up. Stuck/Sunk floats can manifest in all sorts of ways depending on the severity. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted July 16 Report Share Posted July 16 Carbs out of sync would get *very* rough before actually quitting, that sounds unlikely. I like the stuck float idea...maybe the slip slung a float corner out and it stuck against the wall of the bowl. What was the temp and fuel type? If it was very hot and you use ethanol fuel, it's possible that when you pulled power back any vapor in the lines formed a bubble that blocked fuel flow. There might have been sufficient fuel pressure/flow at higher RPM to move past any vapor, but not at idle. Quote Link to comment Share on other sites More sharing options...
Eddie Cesnalis Posted July 16 Author Report Share Posted July 16 70F+ with an inversion. I did notice high fuel pressure at idle before I took off. I also noticed high egt's. It did stop abruptly, a stuck float feels most likely to me. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted July 16 Report Share Posted July 16 35 minutes ago, Eddie Cesnalis said: 70F+ with an inversion. I did notice high fuel pressure at idle before I took off. I also noticed high egt's. It did stop abruptly, a stuck float feels most likely to me. Yeah, probably not vapor at 70-ish. If you can identify which float has the issue, you can ever-so-slightly bend the pin to create more clearance for the float. I did this when I had a stuck float and never had this again. Are these the older bowls with the holes in the bottom? Those seem to have more issues based on my limited experience. I have had zero issues since getting the new solid-bottom bowls. Quote Link to comment Share on other sites More sharing options...
Mike Koerner Posted July 17 Report Share Posted July 17 Well, this sounds a lot like the float guide problem I wrote about a couple months ago, including both the rough running during a slip and the engine quiting on final. I've got a lot of hours since replacing the bowls, including a couple more flights back and forth across the country, and it still runs perfectly. Quote Link to comment Share on other sites More sharing options...
procharger Posted July 17 Report Share Posted July 17 Make sure your throttle stop screws almost touch when pulling throttle all the way back so your idle doesn't get to low, mine barely touch. with cables things change during hot and cold weather I don't let mine go below 1600 or so RPM. I have seen some of the screws backed off a fair amount not a good idea, like I said things change. Quote Link to comment Share on other sites More sharing options...
procharger Posted July 17 Report Share Posted July 17 If its running smooth, starting good, idling good, numbers look good on EGT and CHT I don't mess with mine. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted July 17 Report Share Posted July 17 I check my sync twice a year typically, once in Spring and once in Autumn. Usually I don't have to change it. Quote Link to comment Share on other sites More sharing options...
Eddie Cesnalis Posted July 17 Author Report Share Posted July 17 I got new float bowls 3 years ago but then poluted my fuel system with rust from my transfer tank (new one is aluminum with fill rite particulate filter). I have had 4 rough running take off attempts fixed with float bowl cleanings where debris was minimal. The rust was impossible to see when in suspension but if I didn't fly for 10 days it would settle. We refreshed much of the fuel system but not the float/guides. It's possible that the settled rust on the guide pin / float could have created some deposit to stick on. Slipping induced also fits so I will check for Andy's slighly bent pin fix. Quote Link to comment Share on other sites More sharing options...
Mike Koerner Posted July 18 Report Share Posted July 18 Ok. Slipping can stir up debris on the bottom of the bowls. That may be what you're seeing. Turbulence or pitching up or down steeply may cause the same problem. I think the latter happened to me a couple times years ago. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted July 18 Report Share Posted July 18 18 hours ago, Eddie Cesnalis said: I got new float bowls 3 years ago but then poluted my fuel system with rust from my transfer tank (new one is aluminum with fill rite particulate filter). I have had 4 rough running take off attempts fixed with float bowl cleanings where debris was minimal. The rust was impossible to see when in suspension but if I didn't fly for 10 days it would settle. We refreshed much of the fuel system but not the float/guides. It's possible that the settled rust on the guide pin / float could have created some deposit to stick on. Slipping induced also fits so I will check for Andy's slighly bent pin fix. Yikes, sounds like a full fuel flush and filter check/replacement might be in order. Have you had the carbs rebuilt since the contamination incident? That's just a few hundred bucks and might solve all your issues if some of that junk is lingering in the carb fine parts like needle or conical valve seat. At the very least you could remove the carbs, take the bowls off and diaphragms out, and blast them with carb cleaner until everything drips off of them. Quote Link to comment Share on other sites More sharing options...
Eddie Cesnalis Posted July 18 Author Report Share Posted July 18 12 minutes ago, FlyingMonkey said: Yikes, sounds like a full fuel flush and filter check/replacement might be in order. Have you had the carbs rebuilt since the contamination incident? That's just a few hundred bucks and might solve all your issues if some of that junk is lingering in the carb fine parts like needle or conical valve seat. At the very least you could remove the carbs, take the bowls off and diaphragms out, and blast them with carb cleaner until everything drips off of them. We did a targeted but effective clean up including re-coating one of the wing tanks and new filters. Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted July 18 Report Share Posted July 18 Be careful where you put blame on contaminated fuel from debris. Starting inside the fuel tank there is a fuel filter. I call it a strainer because the holes are fairly big and will only stop larger pieces of debris. Next there is a fine mesh filter in the instrument panel. I’ve only seen once where there was any serious debris during an inspection. Next you have your fine mesh gascolator filter. It has to be a minuscule debris to get past this and something that small is not larger enough to block the main jet. Then, but not least the mechanical fuel pump has a filter in it. So bottom line if you’re getting debris in your carb bowl it is coming after it leaves the pump. This only leaves that short hose from the pump, hoses from the fuel block assembly on the balance tube to the carbs or a flake off a float. Quote Link to comment Share on other sites More sharing options...
procharger Posted July 18 Report Share Posted July 18 Roger tell me about the strainer in fuel tank is there a check for that strainer? I have never seen anything in my float bowls at all in 1000 hrs. and years of flying. Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted July 18 Report Share Posted July 18 They filter / strainer in each fuel tank is mounted to the metal fuel bulkhead on the other side of the fuel sight tube. It’s about 1” in diameter. There are a bunch of holes in it. No screen. Something about 1/4” may get held back there. There was a time during FD’s earlier years they wanted those inspected every 100 or 200 hours. I forgot which. Now it’s at 1000 hours. Since 2006 I have never seen anything in these and never have heard anyone saying they found a bunch of debris. From the maintenance manual checklist. “Fuel Intake Filter. Check intake filter every 1000 hrs or after negative fuel flow test.” Quote Link to comment Share on other sites More sharing options...
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