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YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: playerpage ()
Date: July 05, 2021 11:58AM

Hello all,

This thread is a follow-up to the previous one:

SUCCESS!!....At least in ferreting out the problem

Pictures will be spread over three or four posts.

-----

The carburetor removed, the choke plate screws were nowhere to be found inside it. The carb side of the turbo impellor is very scratched up, the exhaust side appears unaffected. The impellor has a rattling sound when turning by hand, and turning by hand will intermittently jam, all indicating debris in there.

Taking the turbo out and examining the orifices shows no scratches on the piping, but as American Mel pointed out in the last thread, the speed with which the screws from the plate would have been sucked through when they came loose would mean they weren't exactly sliding around in there.

Did they stop at the impellor? Were they sucked into the engine? An investigation with the scope camera shows mostly flooding from the rich mixture occurring in the passenger head cylinders 1,3, and possibly 5--due to the broken choke. Cylinders 2,4,and 6 on the drivers side look dry, and I don't see scoring.

The kicker is the compression test:

Driver's side: 2=100 psi.........Passenger side: 1=112 psi
.....................4=130 psi.................................3=110 psi
.....................6=115 psi.................................5=NO READING

I made several attempts at the test, but nothing. I did remove the tester and just put my finger on the hole. I could feel compression, I'm not sure how strong it is. Hooked the tester back up, still no reading.

It would appear that the screws did not affect the engine directly, but the bad carb may have done damage another way. Anyone want to change my mind? I'll take unverified stories about compression in 5 always being un-readable, because it is so powerful no tester can contain it.

Pictures follow, in order of their description.

-----

Eric C. Player
Fargo, North Dakota
MEMBER: CORSA National, Central Coast CORSA, South Coast CORSA, Vintage CORSA, Sfba CORSA, and Great Plains Corvair Club.
THEN: 1965 Monza 110, Canary Yellow - 1965 Corsa 180 Turbo, Red - 1966 Monza 110, Purple - 1967 Monza 140, Red - 1966 500 110, Black; nicknamed "Shadow" - 1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo, Blue; nicknamed "Bluvair"
---------------------------------------
"He cautioned me not to take notes. It would not have helped if I had, as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: playerpage ()
Date: July 05, 2021 11:59AM

Cylinders 1,3,5

Eric C. Player
Fargo, North Dakota
MEMBER: CORSA National, Central Coast CORSA, South Coast CORSA, Vintage CORSA, Sfba CORSA, and Great Plains Corvair Club.
THEN: 1965 Monza 110, Canary Yellow - 1965 Corsa 180 Turbo, Red - 1966 Monza 110, Purple - 1967 Monza 140, Red - 1966 500 110, Black; nicknamed "Shadow" - 1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo, Blue; nicknamed "Bluvair"
---------------------------------------
"He cautioned me not to take notes. It would not have helped if I had, as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: playerpage ()
Date: July 05, 2021 12:00PM

Cylinders 2,4,6

Eric C. Player
Fargo, North Dakota
MEMBER: CORSA National, Central Coast CORSA, South Coast CORSA, Vintage CORSA, Sfba CORSA, and Great Plains Corvair Club.
THEN: 1965 Monza 110, Canary Yellow - 1965 Corsa 180 Turbo, Red - 1966 Monza 110, Purple - 1967 Monza 140, Red - 1966 500 110, Black; nicknamed "Shadow" - 1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo, Blue; nicknamed "Bluvair"
---------------------------------------
"He cautioned me not to take notes. It would not have helped if I had, as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: MattNall ()
Date: July 05, 2021 12:46PM

What the pressure readings on cylinder's 1,3 & 5 ?

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
...............110-PG.................................................Webered-Turbo

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: RobertC ()
Date: July 05, 2021 01:37PM

MattNall Wrote:
-------------------------------------------------------
> What the pressure readings on cylinder's 1,3 & 5 ?

Fom his first post:

The kicker is the compression test:

Driver's side: 2=100 psi.........Passenger side: 1=112 psi
...............4=130 psi.........................3=110 psi
...............6=115 psi.........................5=NO READING

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: American Mel ()
Date: July 05, 2021 01:58PM

Eric, can you get a view of the Valves in Cyl. #5?
Does your Borescope have the ability to look sideways? (angled Mirror?)
Would be nice to see if it is a dropped valve seat, or ????

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border, I am not at the end of the world, but you can see it from here.

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: steve c goodman ()
Date: July 05, 2021 02:17PM

Eric remove the compressor hsng from turbo and see what is rattling around between the wheel and the scroll. Easy with 7/16" wrench

best wishes, Steve
Rear Engine Spec. Inc. Golden, Colo.

1962 spyder 3.0L turbo---1965 Crown V8
1967 monza 110/4---1968 monza 110/4
1971 amante gt 110/4
CORSA/RMC/PPCC/V8 Registry

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: playerpage ()
Date: July 05, 2021 02:29PM

Is this enough of a view on Cylinder 5? I do have an angled mirror, I'll try to take a look, soon--my kids wore down my phone battery!

I once lost pressure due to a broken spring--what else can cause compression loss besides dropped seat or bad spring?

I decided to set the turbo aside for now. It's not going anywhere.

Eric C. Player
Fargo, North Dakota
MEMBER: CORSA National, Central Coast CORSA, South Coast CORSA, Vintage CORSA, Sfba CORSA, and Great Plains Corvair Club.
THEN: 1965 Monza 110, Canary Yellow - 1965 Corsa 180 Turbo, Red - 1966 Monza 110, Purple - 1967 Monza 140, Red - 1966 500 110, Black; nicknamed "Shadow" - 1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo, Blue; nicknamed "Bluvair"
---------------------------------------
"He cautioned me not to take notes. It would not have helped if I had, as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'



Edited 2 time(s). Last edit at 07/05/2021 02:38PM by playerpage.

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: American Mel ()
Date: July 05, 2021 03:16PM

I was hoping to see a picture of the head and valves, actually.

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border, I am not at the end of the world, but you can see it from here.

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: playerpage ()
Date: July 05, 2021 03:20PM

I'll be opening the valve cover probably after dinner. Sounds like you're asking me to take the head off though....? Really hoping to avoid that.

Eric C. Player
Fargo, North Dakota
MEMBER: CORSA National, Central Coast CORSA, South Coast CORSA, Vintage CORSA, Sfba CORSA, and Great Plains Corvair Club.
THEN: 1965 Monza 110, Canary Yellow - 1965 Corsa 180 Turbo, Red - 1966 Monza 110, Purple - 1967 Monza 140, Red - 1966 500 110, Black; nicknamed "Shadow" - 1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo, Blue; nicknamed "Bluvair"
---------------------------------------
"He cautioned me not to take notes. It would not have helped if I had, as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: American Mel ()
Date: July 05, 2021 03:46PM

NO! eye popping smiley
Just wondered if you could use your borescope to look at the head/valves, instead of the piston/cylinder.
Rotate the view 180 degrees.

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border, I am not at the end of the world, but you can see it from here.

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: playerpage ()
Date: July 05, 2021 04:20PM

Right.

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: 2ragtops ()
Date: July 05, 2021 08:37PM

One of our younger club members, a few years ago, had a similar issue.

He had worked on his carbs, and apparently failed to properly install and tighten the throttle plate screws.

He drove around for 40-50 miles and then it happened.

I towed him home, and several hours later, he called saying he pulled the head
and found the screws lying on top of one of the cylinders. No damage, he even reinstalled the screws and has been running ever since.

Bob Bauer

Show-Me Corvairs

1966 Monza Convert 140 P/G with A/C, plastic wheel with tele-column am-fm posi-traction

1928 Ford Model A 2 door sedan

House Springs, Missouri

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: cnicol ()
Date: July 06, 2021 08:28AM

Over the years I've found a throttle plate screws embedded in the piston or head. None were on a turbo though, that adds an extra thing or two to the equation.

FWIW, proper installation of throttle and choke plate screws involves "peening" (hit with small hammer or punch) the exposed threads sticking out beyond the throttle or choke shaft.

This action expands or "mushrooms" the exposed end of the screw so it is impossible for it to unscrew. Next time the choke or throttle plate needs to be removed for service, the exposed threads get filed flush so the screw can come out. After one use, screws are discarded and replaced with new, full length screws.

Craig N. Coeur d'Alene ID.
66 Black Monza 4dr, 4.2L V8 49k
61 Seamist Jade Rampside 140 PG
65 Canadian Monza 4dr 110/PG 40k
66 Sprint Corsa convt - First car! Re-purchased 43 years later
2+2 gnatsuM 5691

+17 Tons of parts

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: Cheepfk ()
Date: July 06, 2021 08:47AM

I doubt two tiny screws are the problem (if they were even there in the first place). Judging by your photos it looks like your engine was "rebuilt" using sloppy parts. If that were my engine I'd go through the whole thing to insure a quality rebuild the next time. You'll be happier for the long run that way.

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: cnicol ()
Date: July 06, 2021 09:33AM

Compression around 110# is definitely low. #4 at 130# is the only cylinder that's on spec. Vertical stripes in cylinders indicate wear, either very high miles or contamination from intake air or dirty oil. #5 at zero psi is likely a burned valve or missing valve seat. The latter would be hard to imagine though, given the good condition of the piston crown. I'm going with badly burnt valve.

"I'll take unverified stories about compression in 5 always being un-readable, because it is so powerful no tester can contain it." Well, that's true but we never speak or write about it. grinning smiley

The dinged-up compressor wheel is unfortunate but the good news is the cold side is inexpensive and there are lots of good used ones because the hot side is the one that's always bad in my experience.

Since the engine has proven reliable as-is during your recent 3400 mile trip, your next step depends on your budget really. You could just repair problems (valve job, turbo compressor, missing screws) or you could go through the whole engine and make it really fresh.

Craig N. Coeur d'Alene ID.
66 Black Monza 4dr, 4.2L V8 49k
61 Seamist Jade Rampside 140 PG
65 Canadian Monza 4dr 110/PG 40k
66 Sprint Corsa convt - First car! Re-purchased 43 years later
2+2 gnatsuM 5691

+17 Tons of parts

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: 66vairman ()
Date: July 06, 2021 09:42AM

cnicol Wrote:
-------------------------------------------------------
> Over the years I've found a throttle plate screws embedded in the piston or head. None were on a turbo though, that adds an extra thing or two to the equation.
>
> FWIW, proper installation of throttle and choke plate screws involves "peening" (hit with small hammer or punch) the exposed threads sticking out beyond the throttle or choke shaft.
>
> This action expands or "mushrooms" the exposed end of the screw so it is impossible for it to unscrew. Next time the choke or throttle plate needs to be removed for service, the exposed threads get filed flush so the screw can come out. After one use, screws are discarded and replaced with new, full length screws.

Your description is the best method. I have run into folks who insisted red Loctite worked, but heat and gasoline are good at neutralizing red Loctite.

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: playerpage ()
Date: July 06, 2021 10:16AM

Cnicol,

That's a great bit of info I wish I'd had three years ago when I picked up the YH carburetor.

I'm sure the issues with the passenger head have to do with your mileage suggestion. It was last serviced about 5000 miles ago, with as you know 3000 of those miles added in the last couple of months. Before that, it was a donor head.

Cheep,

Please review the issue. The engine had thousands of dollars worth of work done by one of the best men in the hobby just before being driven halfway across the country. The driver's side head was one of the items serviced then. The carburetor, less than three years out from a rebuild, was not on the agenda at that time. Neither were the turbo, or passenger side head. However, I took the turbo apart about two years ago. The damage was not there then.

In other words, the damage sustained is recent, and only involves the parts not addressed in the previous service.

All,

I will be looking deeper today.

Eric C. Player
Fargo, North Dakota
MEMBER: CORSA National, Central Coast CORSA, South Coast CORSA, Vintage CORSA, Sfba CORSA, and Great Plains Corvair Club.
THEN: 1965 Monza 110, Canary Yellow - 1965 Corsa 180 Turbo, Red - 1966 Monza 110, Purple - 1967 Monza 140, Red - 1966 500 110, Black; nicknamed "Shadow" - 1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo, Blue; nicknamed "Bluvair"
---------------------------------------
"He cautioned me not to take notes. It would not have helped if I had, as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: joelsplace ()
Date: July 06, 2021 11:40AM

Check the valve adjustment on that cylinder before taking the head off. It could be that simple.

Joel
Northlake, TX
5 Ultravans, 119 Corvairs and counting...

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Re: YH Carburetor Shake-Apart -- Where Things Stand Currently
Posted by: 63turbo ()
Date: July 06, 2021 11:52AM

The screw could also be holding open one of the valves on #5.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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