This site uses cookies to maintain login information on FarmallCub.Com. Click the X in the banner upper right corner to close this notice. For more information on our privacy policy, visit this link: Privacy Policy
NEW REGISTERED MEMBERS: Be sure to check your SPAM/JUNK folders for the activation email.
Compression test
Forum rules
Notice: For sale and wanted posts are not allowed in this forum. Please use our free classifieds or one of our site sponsors for your tractor and parts needs.
Notice: For sale and wanted posts are not allowed in this forum. Please use our free classifieds or one of our site sponsors for your tractor and parts needs.
-
- 5+ Years
- Posts: 17
- Joined: Tue Mar 21, 2017 9:20 pm
- Zip Code: 52653
Compression test
Hi everyone,
I finally had a chance to run a compression test on my 58 loboy here's the results...
#1
75 dry 95 wet
#2
0
#3
95 dry 110 wet
#4
0
Any suggestions where to go from here? Should have the chance to wrench this weekend!
Also don't know if it's relevant but we had the cub sandblasted and painted last fall, I've read since then that sandblasting can cause issues. Thanks everyone for all the help so far, would really like to get this loboy running again before the next snow!
I finally had a chance to run a compression test on my 58 loboy here's the results...
#1
75 dry 95 wet
#2
0
#3
95 dry 110 wet
#4
0
Any suggestions where to go from here? Should have the chance to wrench this weekend!
Also don't know if it's relevant but we had the cub sandblasted and painted last fall, I've read since then that sandblasting can cause issues. Thanks everyone for all the help so far, would really like to get this loboy running again before the next snow!
-
- Team Cub Mentor
- Posts: 5609
- Joined: Thu Aug 03, 2006 6:20 am
- Zip Code: 43358
- Tractors Owned: 48 Cub Diesel (Cubota)
53 Cockshutt 20 restored (Shooter)
52 Cockshutt 20 unrestored
47 Leader "B" (Herckie)
49 Leader "D" (Princess)
49 Leader "D" very rough
48 Leader "D" unrestored
Kubota B6200E
Kubota B6200HST
Kubota B8200HST-D - Circle of Safety: Y
- Location: OH West Mansfield
Re: Compression test
First, look for stuck valves on #s 3 & 4. It's almost certain you'll find that as the problem. Once free'd up, repeat your test.
-
- 10+ Years
- Posts: 4974
- Joined: Fri Oct 29, 2010 11:34 pm
- Zip Code: 36558
- 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: Compression test
Gary Dotson wrote:First, look for stuck valves on #s 3 & 4. It's almost certain you'll find that as the problem. Once free'd up, repeat your test.
I think Gary meant #2 & #4..... Could be intake or exhaust (or maybe both). Good Luck.
Stan in LA (lower AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)
-
- Team Cub Mentor
- Posts: 20336
- Joined: Fri Jul 02, 2004 9:52 pm
- Zip Code: 65051
- Circle of Safety: Y
- Location: Mo. Linn
Re: Compression test
Cylinders #2 and 4.
Valve cover, hood, and spark plugs removed. Search function, there are several tips on how to unstick valves.
Cub valves frequently stick when the tractor has been setting for a long time. Proper preparation, I doubt that sand blasting material got into the engine.
Valve cover, hood, and spark plugs removed. Search function, there are several tips on how to unstick valves.
Cub valves frequently stick when the tractor has been setting for a long time. Proper preparation, I doubt that sand blasting material got into the engine.
I have an excuse. CRS.
-
- Team Cub Mentor
- Posts: 5609
- Joined: Thu Aug 03, 2006 6:20 am
- Zip Code: 43358
- Tractors Owned: 48 Cub Diesel (Cubota)
53 Cockshutt 20 restored (Shooter)
52 Cockshutt 20 unrestored
47 Leader "B" (Herckie)
49 Leader "D" (Princess)
49 Leader "D" very rough
48 Leader "D" unrestored
Kubota B6200E
Kubota B6200HST
Kubota B8200HST-D - Circle of Safety: Y
- Location: OH West Mansfield
Re: Compression test
Thanks for correcting me, Stan! It happens, you know.
-
- 10+ Years
- Posts: 4974
- Joined: Fri Oct 29, 2010 11:34 pm
- Zip Code: 36558
- 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: Compression test
Yeah, to all of us!! I just call it fat fingering the keys. Dale, in a recent post, called it "finger fart".Gary Dotson wrote:Thanks for correcting me, Stan! It happens, you know.
Stan in LA (lower AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)
-
- 5+ Years
- Posts: 17
- Joined: Tue Mar 21, 2017 9:20 pm
- Zip Code: 52653
Re: Compression test
Would lack of compression in 2 cylinders keep the motor from popping off when you crank it over? Thanks everybody will send an update ( and probably a lot more questions! ) in a couple days!
-
- 10+ Years
- Posts: 4974
- Joined: Fri Oct 29, 2010 11:34 pm
- Zip Code: 36558
- 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: Compression test
IMHO, yes. Especially if the engine has not been run in a while. There's just too much working against it to run on 2 cylinders.Papacub wrote:Would lack of compression in 2 cylinders keep the motor from popping off when you crank it over? Thanks everybody will send an update ( and probably a lot more questions! ) in a couple days!
Stan in LA (lower AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)
- Slim140
- 5+ Years
- Posts: 4908
- Joined: Wed Nov 22, 2017 6:24 am
- Zip Code: 00000
- Tractors Owned: .
1970 International 140
1972 International 140
1949 John Deere A
1993 Ford 4630 W/Loader
1965 John Deere 110
1961 Cub Cadet Original - Circle of Safety: Y
Re: Compression test
staninlowerAL wrote:IMHO, yes. Especially if the engine has not been run in a while. There's just too much working against it to run on 2 cylinders.Papacub wrote:Would lack of compression in 2 cylinders keep the motor from popping off when you crank it over? Thanks everybody will send an update ( and probably a lot more questions! ) in a couple days!
Agree with this. Think of it like having diarrhea and only being able to squeeze one cheek, you can't hold the compression in and it will take the easiest path.
Every home is a school, what are you teaching?
- LRiddle
- 5+ Years
- Posts: 488
- Joined: Wed Mar 02, 2016 11:57 am
- Zip Code: 44278
- Tractors Owned: .
1951 Farmall Cub - Chesty
Woods 59 belly mower
54A blade
1956 Gravely L
Dozer blade
Tiller
Rotary Plow - Circle of Safety: Y
- Location: Tallmadge, OH
Re: Compression test
Chipmaker wrote:staninlowerAL wrote:IMHO, yes. Especially if the engine has not been run in a while. There's just too much working against it to run on 2 cylinders.Papacub wrote:Would lack of compression in 2 cylinders keep the motor from popping off when you crank it over? Thanks everybody will send an update ( and probably a lot more questions! ) in a couple days!
Agree with this. Think of it like having diarrhea and only being able to squeeze one cheek, you can't hold the compression in and it will take the easiest path.
Luke Riddle
Tallmadge, Ohio
1951 Cub - Chesty
Tallmadge, Ohio
1951 Cub - Chesty
"You can't believe everything you read on the internet." - Abraham Lincoln
-
- Team Cub
- Posts: 17214
- Joined: Sun Feb 02, 2003 2:59 pm
- Zip Code: 55319
- Circle of Safety: Y
- Location: MN
Re: Compression test
Papacub wrote:Would lack of compression in 2 cylinders keep the motor from popping off when you crank it over? Thanks everybody will send an update ( and probably a lot more questions! ) in a couple days!
As already stated, the odds are strongly against you. Particularly if one of the no-compression cylinders has a stuck intake valve. The two working cylinders will have little chance of drawing enough vacuum to pull any fuel in.
- Don B.
- 5+ Years
- Posts: 414
- Joined: Thu Jul 02, 2015 12:02 pm
- Zip Code: 25314
- Tractors Owned: 1948 Cub (looks pretty)
1951 Cub (does the work)
1952 Cub (sold) - Circle of Safety: Y
- Location: Charleston, WV
Re: Compression test
Think of it like having diarrhea and only being able to squeeze one cheek, you can't hold the compression in and it will take the easiest path.
Ah. And, sadly, I actually understood that.
-
- 5+ Years
- Posts: 17
- Joined: Tue Mar 21, 2017 9:20 pm
- Zip Code: 52653
Re: Compression test
Thanks everyone for all the great advice...I had the valve closest to the driver stuck open on #4...tapped it loose and soaked everything with pub blaster...next question, front to back which are the intake and which are the exhaust valves? I'd like to positively find tdc on #1 to triple check timing before putting everything back together...
Thanks again in advance you gentlemen are lifesavers!
Thanks again in advance you gentlemen are lifesavers!
-
- 10+ Years
- Posts: 4974
- Joined: Fri Oct 29, 2010 11:34 pm
- Zip Code: 36558
- 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: Compression test
With the valve cover off, rotate the engine until both the valves next to the radiator are closed which is the compression stroke for #1 cylinder. The mark on the C/S pulley and the pointer should align. If you want to go a step further, while the piston is positioned as described above, remove the #1 spark plug and fill the remaining void above the piston with something like transmission fluid or other light weight oil until the liquid is at the top of the spark plug hole. Rotate the crankshaft back and forth a few degrees and find the spot that the liquid is at the highest point. That's TOP DEAD CENTER/compression stroke. (If the liquid will not hold steady it's leaking past the rings or the valves on that cylinder.) Compare with the timing marks on the C/S pulley and pointer. The distributor rotor will be pointing to the #1 spark plug wire on the distributor cap. Or you can check with a timing light connected to #1 with the engine running.
Stan in LA (lower AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)
-
- Team Cub Mentor
- Posts: 20336
- Joined: Fri Jul 02, 2004 9:52 pm
- Zip Code: 65051
- Circle of Safety: Y
- Location: Mo. Linn
Re: Compression test
If you haven't moved or removed the distributor, rotate the engine until the TDC mark on the pulley lines up with the pointer. Check to see if the rotor lines up with the #1 spark plug wire tower on the distributor cap. If the rotor points to #1 spark plug tower you are on the correct TDC. If the rotor points at the #4 plug tower, rotate the engine one full turn until the mark and pointer line up. You are then on #1 cylinder, TDC.
If you use Stan's method for determining TDC, be sure to crank the engine over several times with the spark plug out to clear excess fluid from the cylinder.
If you use Stan's method for determining TDC, be sure to crank the engine over several times with the spark plug out to clear excess fluid from the cylinder.
I have an excuse. CRS.
Who is online
Users browsing this forum: No registered users and 26 guests