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Cylinder compression

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maybeacub
5+ Years
5+ Years
Posts: 40
Joined: Sun Sep 24, 2017 7:33 am
Zip Code: 10517
Tractors Owned: IH Cub 1972
Mahindra 2615HST
Ariens GT16
Sold- Oliver Super 55
Location: Mohegan Lake,NY
Contact:

Cylinder compression

Postby maybeacub » Fri Oct 27, 2017 1:27 pm

I have been looking for compression data for without any luck. Can anyone tell me what compression to expect running a dry compression test on both the flat and domed piston models. I'm going to look at a 60s and 70s model year cub today.
Thanks!
Greg
"I have nothing to do today and by noon I want to be half done"

1972 Cub
Ariens GT16
Mahindra 2615

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AL Farmall Boy
10+ Years
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Joined: Tue Aug 10, 2010 6:38 pm
Zip Code: 35630
Circle of Safety: Y

Re: Cylinder compression

Postby AL Farmall Boy » Fri Oct 27, 2017 2:05 pm

From my experience I would say 90 to 150 psi it will run. They need to be close across the board . If not the really low one will be the problem.....probably a stuck valve if anything.
Regards,
Chase
205-368-5339
ihfarmallrtr@gmail.com

:tractor: Follow my page "Alabama Tractor Pickers" on YouTube & Facebook! :tractor:

maybeacub
5+ Years
5+ Years
Posts: 40
Joined: Sun Sep 24, 2017 7:33 am
Zip Code: 10517
Tractors Owned: IH Cub 1972
Mahindra 2615HST
Ariens GT16
Sold- Oliver Super 55
Location: Mohegan Lake,NY
Contact:

Re: Cylinder compression

Postby maybeacub » Fri Oct 27, 2017 2:52 pm

First tractor was 70 in front cyl and 80 other 3.
"I have nothing to do today and by noon I want to be half done"

1972 Cub
Ariens GT16
Mahindra 2615

staninlowerAL
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Tractors Owned: Cubs: (3)'49's, (1 is for parts), (1)'57 IH Cub LoBoy w/FH, (2)154 Number Series Loboys, (1 is for parts), '76 Longstripe w/FH, Mowers: C-22, Bush Hog 412, Pennington 59, Woods RM42CF, Woods 42, assorted FCub plows, planters, discs, etc. OTHERS: '49 AC B & Ind. Sickle mower, '61 AC D12 Ser 2, '52 8N, '56 Ferguson 35 Deluxe, '47 & '49 Avery V, '53 MM BG (offset), '51 JD M (regular), '56 JD 420C, with Blade and fire plow, '85 JD 850 (Yanmar) w/72" belly mower, '76? Yanmar 2TR15 1500 & Bush Hog SQ42S-2 mower, '78? FORD Dexta, '86 FORD LGT14D & 48" Mower, (2)Cub Cadets & Mowers (MTD), (4) Sears Surburban's, other MTD mowers, Jeeps & other misc. "treasures"
Circle of Safety: Y
Location: AL (Southwest)

Re: Cylinder compression

Postby staninlowerAL » Fri Oct 27, 2017 3:48 pm

If it's been sitting for a while and not been run, the rings may be stuck. Seafoam in the cylinders and let set/soak for a couple days might help. Can't hurt anything. Before you try to start it, prime the oil pump and add Seafoam to the fuel tank also. Expect to have starting problems with the compression that low.
Stan in LA (lower AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)

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txcublover
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Tractors Owned: 1951 Cub (141620)
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Re: Cylinder compression

Postby txcublover » Fri Oct 27, 2017 4:22 pm

In the service manual available from this website it said compression should be 125PSI. I don't know about domed vs. flat, however.

Eugene
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Re: Cylinder compression

Postby Eugene » Fri Oct 27, 2017 5:44 pm

I'm assuming you haven't purchased the tractor, yet.

Assuming you used the starter to crank over the engine, the dry PSI numbers are low. Although, the tractor would run with those numbers but be weak. I would like to see numbers over 100 and even.

Engine is probably due for an overhaul.
I have an excuse. CRS.

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Glen
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Location: Wa.

Re: Cylinder compression

Postby Glen » Fri Oct 27, 2017 6:15 pm

Hi,
Below is the page from the Cub service manual showing the compression. :)

http://www.farmallcub.info/manuals/gss- ... 000-01.jpg

http://www.farmallcub.info/manuals/gss- ... 001-04.jpg

BigBill
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Re: Cylinder compression

Postby BigBill » Fri Oct 27, 2017 7:28 pm

Seafoam in the crankcase and gas tank will lube the valve guides freeing sticky valves, free stuck rings and reseat them. If only “IF” the tractor has been sitting. It’s not a engine rebuild or refresh in a can. But you will notice the rpm idle speed going higher.
I'm technically misunderstood at times i guess its been this way my whole life so why should it change now.

maybeacub
5+ Years
5+ Years
Posts: 40
Joined: Sun Sep 24, 2017 7:33 am
Zip Code: 10517
Tractors Owned: IH Cub 1972
Mahindra 2615HST
Ariens GT16
Sold- Oliver Super 55
Location: Mohegan Lake,NY
Contact:

Re: Cylinder compression

Postby maybeacub » Fri Oct 27, 2017 7:49 pm

Well it's been a long day. I looked at 3 Cubs today and the 3rd looks like a keeper. Good tires, runs nice, shifts well thru all gears, etc. Has the implements I want and the compression is 110 on all 4 cylinders. Now to get it home.
"I have nothing to do today and by noon I want to be half done"

1972 Cub
Ariens GT16
Mahindra 2615

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txcublover
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Joined: Sun Oct 22, 2017 4:02 pm
Zip Code: 00000
Tractors Owned: 1951 Cub (141620)
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Twitter ID: farmallplay
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Re: Cylinder compression

Postby txcublover » Fri Oct 27, 2017 8:00 pm

Congrats!

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Willy
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Location: Dyer, TN

Re: Cylinder compression

Postby Willy » Fri Oct 27, 2017 10:44 pm

Sounds like a deal to me!
Waking up the ol' Cub

Nah, it's not leaking oil. It's just marking it's territory.

maybeacub
5+ Years
5+ Years
Posts: 40
Joined: Sun Sep 24, 2017 7:33 am
Zip Code: 10517
Tractors Owned: IH Cub 1972
Mahindra 2615HST
Ariens GT16
Sold- Oliver Super 55
Location: Mohegan Lake,NY
Contact:

Re: Cylinder compression

Postby maybeacub » Fri Oct 27, 2017 10:47 pm

With what little I know about Cubs and need to learn I hope so! Let the learning begin. May have to change my username!
"I have nothing to do today and by noon I want to be half done"

1972 Cub
Ariens GT16
Mahindra 2615

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Glen
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Tractors Owned: 1956 Farmall Cub with Fast Hitch, F-11 plow, Disc, Cultivator, Cub-22 mower
Circle of Safety: Y
Location: Wa.

Re: Cylinder compression

Postby Glen » Sat Oct 28, 2017 2:03 am

Hi,
You didn't say what year Cub you bought. It can be told from the serial number.
Below is a 1965 Cub owner's manual. You can learn lots about the Cub reading it. The experts on here recommend reading it, if you never have. It has lots of info about operation, maintenance, and lubrication. It has info for both 6 and 12 volt electrical systems, use the info for whichever system the Cub has.
It might not show some parts for a 6 volt Cub converted to 12 volts by someone. But many of those still have the 6 volt starter, from what pics I've seen on here. :)

http://farmallcub.com/rudi_cub/www.clea ... index.html

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ricky racer
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Re: Cylinder compression

Postby ricky racer » Sat Oct 28, 2017 5:29 am

We want pictures!!
1929 Farmall Regular
1935 John Deere B
1937 John Deere A
1941 John Deere H
1952 John Deere B
1953 Farmall Cub

maybeacub
5+ Years
5+ Years
Posts: 40
Joined: Sun Sep 24, 2017 7:33 am
Zip Code: 10517
Tractors Owned: IH Cub 1972
Mahindra 2615HST
Ariens GT16
Sold- Oliver Super 55
Location: Mohegan Lake,NY
Contact:

Re: Cylinder compression

Postby maybeacub » Sat Oct 28, 2017 6:33 am

Reading the manual is definitely on my list. I will get a printed copy for handy reference. The cub is a 73 based on the 242xxx serial number.
Pictures to follow.
"I have nothing to do today and by noon I want to be half done"

1972 Cub
Ariens GT16
Mahindra 2615


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