Allis Chalmers C Fouls Plugs
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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=121115
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Topic: Allis Chalmers C Fouls Plugs
Posted By: ScottyC
Subject: Allis Chalmers C Fouls Plugs
Date Posted: 29 Mar 2016 at 4:25pm
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We have an Allis Chalmers C that we've used for years to mow our lawn. It has almost always had an issue with fouling plugs (Champion J8C) and running rough. Due to our lack of time, we usually just put new plugs in and keep 'er goin'. We would like to take the time to address the issue, so I ran a compression check expecting to find that the rings were bad. All cylinders show about 125 lbs, which from my research should be okay. Any idea why it would have such an issue when it seems to have good compression?
Thanks,
ScottyC
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Replies:
Posted By: Leon n/c AR.
Date Posted: 29 Mar 2016 at 4:39pm
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How many hours of operation before it fouls the plugs? Are the plugs oily? If oily good possibility oil is getting by worn valve guides. Compression sounds good. Have you had valve cover off to see if oil is draining back to sump o k while running. Might want to try step hotter plugs. I like autolite plugs better myself. Leon
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Posted By: ScottyC
Date Posted: 29 Mar 2016 at 5:07pm
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Thanks Leon. I guess the next step would be popping the top off. Do you know what # of Autolites work best?
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Posted By: Hubnut
Date Posted: 29 Mar 2016 at 6:29pm
Autolite 295 or AC45. Sounds like she's due for an overhaul. If it's not burning too much oil, I'd put hotter plugs in and go. You may be able to get another season out of her.
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1940 B "Lucy"
1941 B w/ Woods L59 "Flavia"
1942 B w/ finish mower "Dick"
1941 C w/ 3-point "Maggie"
1947 C SFW w/ L306 "Trixie"
1972 314H
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Posted By: Alberta Phil
Date Posted: 29 Mar 2016 at 6:37pm
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Try the Autolite 295 plugs. Most Allis tractors don't like the Champion plugs made these days.
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Posted By: Larry in NC
Date Posted: 29 Mar 2016 at 7:05pm
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If you have good compression and good power and want to use it for a while without doing engine work, you can use non-foulers on the plugs. You can buy them at most auto supply stores.
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Posted By: Gerald J.
Date Posted: 29 Mar 2016 at 7:07pm
Champion tractor plugs made in the last 20 years or so seem to foul easily and never clean up. They are easily fouled by leaving the choke on a few seconds too long after starting. They don't seem to clean up by running or with a spark plug cleaner. Other brands do much better.
Gerald J.
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Posted By: Dick L
Date Posted: 29 Mar 2016 at 8:00pm
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I wouldn't get in a hurry to take it apart with that kind of compression. It could be running rich, it could be stuck oil rings that can be loosened up with seafoam or one of the other like products. Z-Max being a good one on the high cost end. Valve guides bad enough to cause fouled plugs will smoke bad on start up and then stop or clear up a lot after running for a while. Stuck oil rings that will foul plugs will smoke steady while running and only clear up when the oil rings let loose and start scraping the cylinder walls. If it is not smoking except for a little black it very well could be more fuel than it can burn causing it to foul. You can have scored cylinder walls that will smoke and still carry a good compression. I would say it is the exception though.
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Posted By: Gerald J.
Date Posted: 29 Mar 2016 at 8:51pm
Oil leaking around the intake valve stem is greatest just after the engine is slowed from running fast, so goosing the engine and then going back to idle will show blue smoke from oil if its being sucked through the intake valve guide.
Gerald J.
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Posted By: LeonR2013
Date Posted: 29 Mar 2016 at 9:56pm
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I've put this on here before, but I'd like to help, so here goes. The secret, the real secret to solve your plug problem is ...........chain saw plugs!! Oh no here he goes again. he's old, things like that aren't possible and besides that he's lost his mind. Yep, happens to all of us sooner or later. On the bigger Allis engines (226) older chebby engines etc. I use the same plug that fits a XL923 - 925 Homelite chain saw. So take one of your plugs into the hot handed parts place of your choice. Match them according to size and don't worry about the heat range. After all you are pumping extra oil into the cylinder and that will cool the fire down. Many years ago I was scratching my head trying to find a way to stop a 45 from fowling the plugs. Might get an hour of running and have pull and clean them. Tried the jump spark deal, helped some. Tried the things you put on the plugs that moves he plugs further out of the firing chamber, helped some. Didn't really solve the problem. So as I became balder and balder I jumped sparked my brain and I thought, HEY, chain saw plugs fire in oil in a chain saw, why not in a tractor? That silly thing NEVER mis-fired again. The reason it pumped so much oil out? Before I got the tractor someone had put in pistons and liners and put the rods in backwards. You would not believe the depth of the two grooves cut into the liners, but she ran good after I put in the chain saw plugs. Let me know how it turns out. Leon R Cmo
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Posted By: LeonR2013
Date Posted: 29 Mar 2016 at 10:02pm
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I forgot to say that all the ideas the other guys gave are spot on, but what I've added can get you to where it might be more convenient. I personally suspect the oil rings to be the problem.
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Posted By: Orange Tractors
Date Posted: 30 Mar 2016 at 12:55am
If your C still has the mag I don't know if this will work or not, but it did on my WD that has a distributor. NGK spark plugs. I forget the number, but it is supposed to be the equivalent of the Champion CJ8.
My tractor burns so much oil that it fouled every Champion, AC, and Autolite plug I put in in short order. The first set of NGK's have been in it for four or five years now, I do have a set of four replacements on the dash of the farm truck; they have been there for a couple of years.
I only use the tractor about 10-20 hours a year, so it isn't really cost effective to overhaul it.
Robert
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Posted By: corbinstein
Date Posted: 30 Mar 2016 at 6:41am
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Will the same ones work for a WD? how 'bout a Studebaker Flat-Head with 100psi compression?
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Posted By: alan-nj
Date Posted: 30 Mar 2016 at 7:54am
NGK B-4
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If ignorance is bliss, than happy days are here again.
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Posted By: DougS
Date Posted: 30 Mar 2016 at 8:56am
Toss the Champions and use just about anything else. Get back to us after 100 hours and let us know the results. Any auto parts store would have a cross reference chart. Most discount stores have a chart too. Just stay away from resistor plugs.
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Posted By: Steve in NJ
Date Posted: 30 Mar 2016 at 9:36am
The first thing you need to look at is the condition of the plugs. Are they actually oil fouled or gas fouled. Easy to determine. As Dick mentioned, before I'd pull that engine down, I would first throw those Chimpanze spark plugs in the round file and install a set of Autolite 295's in the holes or another equivalent brand. Do you have blue smoke on start up? Do you have black smoke on start up? Couple things to take into consideration. If blue, that's usually an oil issue. And also how much? A lot of blue, no blue, or a little blue on start-up. (guides, oil rings etc.) If black, usually an overfueling issue. (Carb usually-sinking float debris or gunk) Once you determine which is happening, then go after either the carb, or as Dick mentioned toss some Seafoam in it and run it a while. Things might clear up, especially with the compression it has. Also inspect the air intake for blockage or water in the oil of the lower cup. All these little things can result in a plug fouling problem. HTH
Steve@B&B
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39'RC, 43'WC, 48'B, 49'G, 50'WF, 65 Big 10, 67'B-110, 75'716H, 2-620's, & a Motorhead wife
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Posted By: LeonR2013
Date Posted: 30 Mar 2016 at 11:24am
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Boy, talk about brain storming! These guys should have been doctors. But how would they have gotten all that good feeling grease on their hands?
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Posted By: LeonR2013
Date Posted: 01 Apr 2016 at 5:23pm
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Sorry it took me so long to wake up but Steve mentioned blockage in the air intake and that is a good possibility. Look inside the rain cap and that should be filled with a steel wool looking material. If not closed off tightly you will find a bunch of dobber nests in there. I got some copper pan scrub pads that fill that up just fine. Leon R Cmo
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