Well I'm back..... Video shows importance of pre flights

18 posts in this topic

Posted

I did my first flight after a year of upgrades. Barely was at 500fpm . Landed and found the problem.

20180519_074850.mp4

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Posted

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Posted (edited)

Glad you made it back ok. That could have gone a lot worse. Thanks for posting, it's always a good reminder.

Clark

Edited by CSCameron

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Posted

Looks like you were setting up a gliding approach.  Glad it didn't come to that.  What were your EGTs doing if you saw them?  JImChuk 

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Posted

Didn't even look at them . I saw I was only at 500ft at the end of the runway when I usually am 1000 . That's when I realized we have a problem. My water temps went up but everything else was good. When I got on the ground I could move the throttle and watch my temps go down . 

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Posted

Welcome back Chop!! 

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Posted

Glad it worked out and you were able to get back!  What a find! 

Great reminder for all of us..... to check and recheck everything!  Cheers Randy 

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Posted (edited)

Hey Chop,  thanks for coming back man.

Just a thought here, if it was running lean enough to underperform that much it must have got kind of hot don't you think?

I'm not sure what I would do about that but maybe someone else here would have an idea what to check over before you put it back in the air.

I bring it up because I've seen sleds meltdown when the engine side carb boot has a cracks in it, and this scenario is kind of like that.

Edited by Yamma-Fox

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Posted

I scooted around 180 and stayed in the pattern. When I was on the ground I could play with the throttle and the temps would drop. Same thing in the air , when I cut back the water temp came to around 160 . Pretty sure the engine is good have the carbs off and the pistons look good. 

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Posted

Exhaust side of the pistons would show scuff marks from excessive EGTs, I believe.  Might be worth it to pull the exhaust manifold to have a peak.  Peace of mind afterwards then if everything looks good.  JImChuk

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Posted (edited)

Yep, and Steve I'm thinking about possible high EGT's here as well (skirt scuff/sieze and or piston dome melting), and not so much the coolant temps.

You would likely see that damage through the exhaust port while cycling the piston past the port.  Guess that'd be something I'd check.

Hopefully there is no problem but like Jim says it'd be something you would want to know about if it were.

Edited by Yamma-Fox
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Posted

Wow! glad everything worked out. i second (or third) the idea to at least pop the exhaust off and look inside the ports and inspect the cylinder walls for scoring before you fly it again.

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Posted

With all the cameras out now that you can pick up for around 20 bucks its beyond me why everyone does not have one in the tool box.  Pulling the springs and popping the elbow out will save you from having to pull the manifold and you can get a good look at the piston running the camera into the y pipe. 

I picked up one that uses wifi to the phone and the picture and video quality really surprised me.  Run it down the plug holes as well to look at the cylinder walls.  I can see it fine on my phone, but going wifi to the laptop and having the big screen is much easier on the eyes.

:BC:

 

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Posted

I have a bore scope so I'll check everything out. I did just get new carb boots , throttle cables, carb kits etc. Hopefully there was just a crack in a boot or some debris keeping me from getting full power. On the ground it runs like a animal but as soon as I'm climbing I can watch my rpms drop

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Posted

Ive seen to retenstion systems... one is a long spring that goes from the front of the  engine to the back and holds the carbs to the engine

 

the second I have seen and the one I use is .032 swisted safety wire... I secure it to the fan cover screw on the front or wherever you can, swist the wire and run it thru that hole on the carb body outside of the area of the slide, then thru the second one and then secure it tothe back part of the engine.....that way at least teh carbs cant fall off....

The photo below shows spring s holding it all in the engine....

DSCN1405.JPG

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Posted

Good Idea but luckily my cowl is pretty much right there and they don't have space to fall completely off. I will look at doing something to hold them though. 

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Posted

I ride old motorcycles known as a Shovelhead Harley, these are known for losing a boot to carb seal and sucking air in this turning the rear piston to sand! (Ask me how I know! C’mon...ask) I’m really glad to see you got back down the right way. I will be adding dropping the upper cowl and checking my carbs to the preflight- I’ve been just reaching in and wiggling - I’ll be changing that to more aggressive maneuvers 

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Posted

There is not much of a groove to hold the carb rubber socket on and with all that shaking and then get fuel on it and all bets are off......

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