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  #51  
Old 08-14-2021, 10:21 AM
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Tony_T Tony_T is online now
 
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Location: Lacey, WA
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For what it's worth, the "R" should be on the Left carburetor for tractor installation. In a pusher, it would then be on the right side of the airplane. Maybe most of the early installations were pushers, or who knows why it is that way.



Picture is from Rotax-Owner videos.
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  #52  
Old 08-14-2021, 10:43 AM
todehnal todehnal is offline
 
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Hi Tony. Well that sure adds a new wrinkle to the problem. As you know, our RV-12s have a tractor installation. If your pics is correct, then my analysis is totally wrong. I consider the left carb to be on the 2-4-side and was certain that I should have found an "L". Well, I've been wrong before. So, here I go again.....Tom
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  #53  
Old 08-21-2021, 07:04 AM
todehnal todehnal is offline
 
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Well, I'm sure glad that I sent my carbs back to Lockwood. They really stepped up to the challenge. They first installed my carbs on their test engine and it ran like KRAP. Hurray, they have seen the problem!! Then they sent the carbs back through their shop and ran them on their test engine again with the same results. Additional carb teardowns, re-assemblies, and installing them back on the test engine finally proved successful. They even installed them on a flying aircraft to verify that they are indeed fixed. In their words "Smooth as glass" Best guess is that their was probably a tiny machining particle in one of the carb body port somewhere that was finally extracted through the multiple cleanings. Probably during the manufacturing process. I have since learned that this is not the first Bing carb to experience this, some of which have simply been replaced.

Yeah, I know. I have not installed and ran them on my engine yet, but I really do have confidence after getting the report. I will know for sure next week, so stay tuned.

I will not go through this again. Should I have carb issues in the future, I will make one attempt in my shop to fix it. If I still have a problem, in the trash they go, and a new set goes on; be-dammed the cost.....Tom
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2013- RV12, Kit #119. N123M First flight Nov21. It's a keeper!
1998- RV-9 tail kit, built and sold
1989- RV-6 tail kit, built and sold
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  #54  
Old 08-21-2021, 08:45 AM
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Tony_T Tony_T is online now
 
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Quote:
Originally Posted by todehnal View Post
Well, I'm sure glad that I sent my carbs back to Lockwood. They really stepped up to the challenge. They first installed my carbs on their test engine and it ran like KRAP. Hurray, they have seen the problem!! Then they sent the carbs back through their shop and ran them on their test engine again with the same results. Additional carb teardowns, re-assemblies, and installing them back on the test engine finally proved successful. They even installed them on a flying aircraft to verify that they are indeed fixed. In their words "Smooth as glass" Best guess is that their was probably a tiny machining particle in one of the carb body port somewhere that was finally extracted through the multiple cleanings. Probably during the manufacturing process. I have since learned that this is not the first Bing carb to experience this, some of which have simply been replaced.

Yeah, I know. I have not installed and ran them on my engine yet, but I really do have confidence after getting the report. I will know for sure next week, so stay tuned.

I will not go through this again. Should I have carb issues in the future, I will make one attempt in my shop to fix it. If I still have a problem, in the trash they go, and a new set goes on; be-dammed the cost.....Tom
Tom, thanks for the update. Good report.
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  #55  
Old 08-24-2021, 05:27 AM
todehnal todehnal is offline
 
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I installed the throttle spring guide plates that Van designed. They really do work well and do add a bit of tension to the throttles. I was glad to see that the bulletin had good pics. It would have been very easy to install the guides backwards without them. I installed and balanced the the carbs, which went well. Ground run showed that the engine runs smooth from idle to wide open throttle and back. No more hiccups or shudders. I can safely say that whatever was causing the rich mixture, probably debris in a tiny carb body port, is fixed, thanks to Lockwood's tenacity.

The test flight showed more power on take off and climb. Probably due to not having such an over rich mixture, However I do still have high EGT on the right side. It did not go into the yellow area like before, but it is still about 125 degrees hotter than the left. Also, I have a vibration in flight that I can feel and makes me think that something on the engine is making contact with the cowling or frame. Not sure what that is, but I need to investigate. So I will keep plugging away at solutions for the rest of the issues, but the carbs certainly fixed the worst of the issues........Tom
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  #56  
Old 08-24-2021, 07:16 AM
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Piper J3 Piper J3 is offline
 
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A couple of itemsÖ

Make sure tail of torsion spring is against the new retaining plate. Itís easy to have tail of spring misplaced Ė I did it. I donít have actual photo, so I made sketch below.

Check to see if rear valve cover on pilot side might be touching the large air duct that feeds the coolant radiator. The clearance at this location is minimal. Also, might want to check engine mount isolator bushings.
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Jim Stricker - EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
Bought Flying RV-12 #120058 Oct 2015 with 48TT - Hobbs now 740

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  #57  
Old 08-24-2021, 08:34 AM
rk2436 rk2436 is offline
 
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My right side egt is always a touch higher than the left. That’s normal. I would recommend a dynamic prop balance now that your carb issue seems resolved.
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  #58  
Old 08-24-2021, 10:15 AM
todehnal todehnal is offline
 
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I was very careful in positioning my springs and have them installed as pictured. Also, I appreciate the prop balance suggestion and plan to do that soon as well.
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2013- RV12, Kit #119. N123M First flight Nov21. It's a keeper!
1998- RV-9 tail kit, built and sold
1989- RV-6 tail kit, built and sold
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  #59  
Old 08-24-2021, 02:43 PM
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DaleB DaleB is offline
 
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We just had our prop balanced a couple of weeks ago. What a different that made. Our "before" was .67 IPS, if I recall correctly. When we finished it was, as near as we cold tell, under .1, more likely around .05 or .06. It was difficult to tell exactly, because a gusting wind had come up, making readings after the last round erratic. I can tell you, it's a lot smoother and more enjoyable to fly now, for sure. And maybe we won't crack any more engine mount tubes.
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Fisher Celebrity (under construction)
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  #60  
Old 08-25-2021, 11:44 AM
todehnal todehnal is offline
 
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Quote:
Originally Posted by DaleB View Post
We just had our prop balanced a couple of weeks ago. What a different that made. Our "before" was .67 IPS, if I recall correctly. When we finished it was, as near as we cold tell, under .1, more likely around .05 or .06. It was difficult to tell exactly, because a gusting wind had come up, making readings after the last round erratic. I can tell you, it's a lot smoother and more enjoyable to fly now, for sure. And maybe we won't crack any more engine mount tubes.
So, did you have any indications that you had a cracked engine mount tube, other than the visual inspection?........Tom
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