Compression test wd45
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=192920
Printed Date: 20 Sep 2025 at 7:08pm
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Topic: Compression test wd45
Posted By: TomYaz
Subject: Compression test wd45
Date Posted: 14 Jan 2023 at 7:08pm
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gasser Dies when try to put past idle...probably bad carb. Anyhoo thought I'd do a compression test From radiator to the seat. - 80psi-80-80-90. Did when tractor was ice cold. How does that rate? Plugs black. ------------- If its not an All-Crop, it all crap! |
Replies:
Posted By: DrAllis
Date Posted: 14 Jan 2023 at 7:14pm
| Throttle WIDE OPEN ?? with a battery charger on the battery ??? pretty poor....125 psi is spec. |
Posted By: TomYaz
Date Posted: 14 Jan 2023 at 7:17pm
Throttle needs to be wide open to do a compression test? Wasnt aware of that... Battery was charged good, no problem cranking. ------------- If its not an All-Crop, it all crap! |
DrAllis wrote:Posted By: DrAllis
Date Posted: 14 Jan 2023 at 7:27pm
| Re-test with throttle wide open. |
Posted By: Les Kerf
Date Posted: 14 Jan 2023 at 10:29pm
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Even if it actually has only 80 psi it shouldn't die when you rev it up if everything else is in order (carb, ignition). Hard starting and low power, yes. |
Posted By: jvin248
Date Posted: 14 Jan 2023 at 11:11pm
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. Has the tractor been sitting a long time so rings got stiff? Fuel restriction is the most common for that scenario. Check the spark plugs against symptom photos. .
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Posted By: TomYaz
Date Posted: 15 Jan 2023 at 12:19am
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Yeah, I dont think the dieing has anything to do with compression, I just decided to check compression anyway becasue the tractor runs poorly even before the the dieing started. Going to re-check the compression. Thanks, know I can always get good insights here. ------------- If its not an All-Crop, it all crap! |
Posted By: TomYaz
Date Posted: 15 Jan 2023 at 12:20am
No tractor has not been sitting. Yes I think its a carb problem. Plugs need replaced. ------------- If its not an All-Crop, it all crap! |
Posted By: WF owner
Date Posted: 15 Jan 2023 at 7:00am
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Check the easy stuff first. Before you tear into the carburetor, make sure your fuel flow is ok. Take the gas line off the carb and turn the gas on. Leave it on for a minimum of a full minute. Flow should stay steady. It's not uncommon to have foreign matter built up in the inlet of the sediment bowl, restricting the flow.
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Posted By: TomYaz
Date Posted: 15 Jan 2023 at 1:51pm
Thats fine, have a inline filter. ------------- If its not an All-Crop, it all crap! |
Posted By: WF owner
Date Posted: 15 Jan 2023 at 3:49pm
Debris plugging the tank outlet could still be your problem. I would definitely take the gas line off the carburetor and check the flow. It wouldn't surprise me if it slows drastically after 30 seconds.
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Posted By: Boss Man
Date Posted: 15 Jan 2023 at 4:15pm
| Plugs are black= over fueling/ lack of air. Is the air cleaner hooked up? When was the last time the air cleaner was serviced? It is winter, any moisture could be creating ice and restricting air flow. Had an Oliver that would run in the shop but not outside. Air cleaner was full of water |
Posted By: TomYaz
Date Posted: 15 Jan 2023 at 4:56pm
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The poor running was back in summer. Addressing it now so Its not about the cold weather. Fuel flow was the first thing I checked, its ok. Service the air cleaner every other year or so. I did new compression test with throttle up.. 125-115-115-120 Going to work on the carb, convert to electronic ignition, change the plugs. ------------- If its not an All-Crop, it all crap! |
Posted By: Les Kerf
Date Posted: 15 Jan 2023 at 8:43pm
That engine will run a long time yet. I would address the ignition first. |