FastEddieB

Thank you!

Here’s the one I’m using from Amazon. [ Looks like they’ve almost doubled in price since I last bought one, but still reasonable.

Are we talking Experimental? If so, there's a John Deere that works well, and the price is right. I've had one in my Sky Arrow for many years with no issues at all.

A chance for a historical anecdote…. When I used to ferry cropdusters, the fuel system was jury-rigged to allow fuel to be carried in the hopper. It held 300 gals but we used to limit it to 150 - still a lot of flying time at 15 gph. On one leg I smelled gas. Like yours, the fuel selector had a slow but steady drip. But if I held upward pressure on it, it stopped. Rather than having to hold it, I came up with this for the remainder of the flight!

In addition to choke travel, there's a small jet down a tube in each float bowl. It feeds the starting circuit (choke) and it easily clogged if there's any debris in the float bowl. You can see it here: It's fresh in my mind since I didn't check to see if that jet was in place in a new float bowl I had installed. It wasn't, and I had horrible rough running with the choke engaged until I moved the jet over from the old float bowl. As an aside, the other float bowl I got form Lockwood did have that jet installed. But I would generally assume its absence, since its listed as a separate part number in the Parts Catalog.

1) Who was the mechanic at Twin Lakes? Please PM me if you don’t want to post it here. 2) Site may need some tuning up. I still can’t reply to this forum from my iPad, though my iPhone and Mac are fine.

CONGRATULATIONS!!! I'd love to check out your new CT. My digs are roughly 100nm WNW, so an easy flight for either one of us: I was at OA7 in my Sky Arrow with a friend in his Remos about a month ago - nice little airport and I'm looking for any excuse to fly on nice days now that I'm post-annual. As an aside, on my iPad running OS 15.1 and Safari, I can no longer seem to post replies to threads on just this forum. I'm logged in and the reply field is greyed out: I tried logging out and back in - no joy. No problem on my iPhone or Mac. Any thoughts? Feel free to PM me if you want to avoid derailing the thread.

To follow up, yesterday afternoon I did a runup and the choke worked perfectly. Threw the cowling back on and did my return-to-service test flight and all was well. Logbooks updated and another Annual Condition Inspection is in the books. Sometimes I get frustrated at how much of my life is spent maintaining, repairing and troubleshooting things. The plane for sure but also home electrical and plumbing, WiFi and other computer gremlins, cars and motorcycles and a zillion other things. Yes, it’s rewarding when a gremlin is tracked down and squashed, but sometimes I agree with Steve Jobs - things should just work!

Sometimes it’s just an obvious screw up. I pulled one of the new float bowls and looking at the bottom of the carb was not seeing the jet for the starter circuit. I had the impression it was at the bottom of a hollow tube. Looking back at the diagram from Rainbow Aviation, I was reminded that the jet was actually located in the bowl. I looked and guess what - the bowls don’t ship with the jet installed. D’oh! So I just transferred the jet from the old bowl to the new one. No wonder it wasn’t working right! Hopefully that’s all it was. Does not explain my rough starting on choke before the annual, but in another hour or so after I switch the other jet I’ll be ready for another runup. Fingers crossed! edited to add: Surprisingly, when I went to move the jet from the old bowl to the new one on the other side (2/4) that bowl did have the jet in place as delivered. Wonder why one did and one didn’t? And no wonder with the choke engaged it felt like it was running on one bank of cylinders!

Thanks for the detailed response. Hopefully this thread will be useful to link to when others have issues. My SOP for a cold start is throttle closed and full choke. The engine has a tiny bit of coarseness for a few seconds until the “soft start” un-retards the timing. The engine runs fine and I can ease the choke off fully over a minute or so as it warms up. The problem here came on suddenly in a couple of starts before my annual. It can’t be the choke discs installed wrong, since the carbs haven’t been seriously messed with since their second overhaul a few years ago and have been working properly. I’m strongly suspecting something blocked in the fuel circuit. Today I plan on pulling the float bowls (again!) and removing the starter circuit jets and see if there’s anything obvious blocking them. I’m considering taking off the starter disc cover to also look for blockage. This seems unlikely, since the starter jet is so tiny compared to the apertures in the starter disc. Anyway, this is getting tedious, and again pushing me towards the “hate” end of my 51 year love/hate relationship with BING carbs.

Just did a runup. Good news: started right up, and after warming up ran it up to almost 5,000 rpm and everything was smooth. After shutting down I don’t see any leaks. Bad news: still VERY rough with choke application. Smooths right out when I turn the choke off. Then, reapplying it slowly the rpm increases smoothly for the first bit of travel, but then starts to run as if one bank of cylinders is cutting out. The choke mechanisms seem to be moving smoothly and together from OFF to ON. Remember, it was showing this behavior shortly before my annual. I have rebuilt BINGs, albeit on motorcycles*, so I know what lies under the choke cover. Neither intake jet appeared clogged. I’m thinking my next step is to pull those covers and take a look for obstructions or anything else amiss. And maybe try blowing air into the jet to make sure the passageway is clear. Has anyone come across this kind of behavior, and if so, what was the fix? Note: I know it’s not a real choke, but it’s easier than saying “starting circuit” each time. Excellent description here: https://electricmotorglider.com/wp-content/uploads/2017/10/CV-Carb-Part-2-web.pdf *I took this photo when rebuilding the carbs on my R100GS to remind me which way the disc went on reassembly:

Thanks all! Video on my watch list for sure.

Those hints: 1) Grease was recommended to hold the gaskets in place. Some may remember I had a bad experience trying to use a gasket sealant, which did not respond well to fuel. In any case, the grease matters. I first tried white lithium grease, then wheel bearing grease. Both were too thin to have much effect. I had some more generic grease in a grease gun, and it was just tacky enough to hold the gaskets in place. 2) Loosening the carb spigot clamps and rotating the carbs slightly greatly increases accessibility to the bowl area. Removing the spring clip temporarily also helps a lot. As always, open to any suggestions to make this recurring chore more palatable!

First of all, kudos to Lockwood - they got the right float bowl and the new gaskets to me in a couple days in spite of Thanksgiving. Both arrived yesterday. As such, I set to work last night. First, I removed the left (in my plane the 1/3 side) float bowl, which was already the new style. Nothing appeared off, the fuel in the bowl seemed at about the right level. I verified the floats were floating at the level of the pins, I swapped gaskets and reassembled. Powered up the electric fuel pump and voila! No leak at all. Yay! On the 2/4 (right) side, the old style float bowl was in fact filled to the brim. As I went to dump the floats out, the problem became obvious: In my plane it’s difficult to maneuver the float bowls back in place due to limited room available. As mentioned upthread, the float pins bend easily, and I apparently slightly bent one slightly during the installation process. That caused the float to stick against the side of the bowl, causing the overflowing. Anyway, reassembled with the new bowl and gasket in place, no leaking with the electric fuel pump on. I’m going to let it warm up a bit - it’s 27°f right now - and hopefully do a ground runup and return-to-service test flight later today. I’ll let you know how it goes. Also, I’ll follow up with a couple hints I found helped with the float bowl removal/replacement process.

Many years ago I bought some black rubber gaskets. I found them too thick to easily get the spring clip seated, so I never used them. I wish I had known about Real Gaskets, but going with official ROTAX parts has its benefits as well.