D-19 Fouling plugs
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Topic: D-19 Fouling plugs
Posted By: AC4W-220
Subject: D-19 Fouling plugs
Date Posted: 29 May 2012 at 11:12am
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We have a D-19 that seems to constantly be fouling plugs. The worst is the cylinder 1 and 6. Also, I was moderately working it over the weekend, and would let it idle after working for a minute or so then would shut it down. When I shut it down I would get a healthy backfire. What issues could I be looking at? It doesn't use any oil to speak of. Is it running too rich? These two situations seem like they could be related. Any input is appreciated, thanks. |
Replies:
Posted By: Bolivar Boy
Date Posted: 29 May 2012 at 12:22pm
| suspect the valve guides are toast in the cylinders you indicated. the backfire is probably from an exhaust valve sticking open, probably from one of the cylinders you mentioned. suggest you run a compression test on all six. cam lobes and bearings could be a problem child also. what kind of oil pressure does this bad boy run at start up cold and what kind of pressure does the engine maintain during full load operation hot. does it drop? is the oil pressure reading steady or does the indicator wiggle around under full load? compression test will tell you a lot. |
Posted By: sks72107
Date Posted: 29 May 2012 at 12:45pm
| Before i would tear into the engine, i would do some basic maintenance to things. Make sure the ignition system is up to spec. Make sure the (im assuming) distributor timing is set properly. Make sure the fuel system is clean and flowing properly, these carbs are simple; pull it, soak it, clean it. And while things are soaking, pull the valve cover and make sure lash is set correctly. Just what i would do. |
Posted By: KGood
Date Posted: 29 May 2012 at 12:53pm
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Your not using champions plugs are you? We had a D17 puller with high compression and it would foul plugs all the time and did not use oil. We found out it was too hot of plug. At the time we didn't know, you would think that hotter equals more power but couldn't keep em firing. If there fouling because of richness I'd think you would notice some black smoke. Then just adjust the carb accordingly. |
Posted By: CTuckerNWIL
Date Posted: 29 May 2012 at 1:03pm
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How is the plug fowled? Is it coated with tarry oil or is it black with soot?
------------- http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF |
Posted By: Brian Jasper co. Ia
Date Posted: 29 May 2012 at 1:29pm
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Cam bearings on a 262 are not pressure lubed, they depend on drain back from the head. Look the ign system over well. A couple cyls not firing well can load up a hot muffler with fuel and be set off by heat/hot spot. I've never seen or heard of an exhaust valve sticking causing a back fire. Every time I've seen a sticking valve a misfire was also present. Throw those Champion plugs and wires from Herschel, TSC, etc away. Get a top quality set of wires and either AC Delco or Autolite plugs. ------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford |
Posted By: 427435
Date Posted: 29 May 2012 at 2:55pm
Hmmm. I always found that a fouled plug (other things OK) was the result of too cold a plug. However, too hot a plug on a hot engine under load can lead to pre-ignition and a sudden loss of power (not to mention pistons with holes in them). ------------- Mark B10 Allis, 917 Allis, 7116 Simplicity, 7790 Simplicity Diesel, GTH-L Simplicity Ignorance is curable-----stupidity is not. |
KGood wrote:Posted By: AC4W-220
Date Posted: 29 May 2012 at 7:46pm
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I will take a look at all ignition parts to check how its all set. We do have champion plugs in it, and Tucker, the fouling on the plug is a wet tarry oil. What does that mean? We have replaced ignition items in the past, but that has probably been longer than I realize also. Thanks for your help. |
Posted By: CTuckerNWIL
Date Posted: 29 May 2012 at 8:58pm
It means you are getting more oil in the cylinder than can be burned at the conditions you now have. Valve guides maybe, rings bad or stuck maybe, leaking valves??? All things that can be sorted out with a check of compression. I would start by running a can of sea foam in half tank of gas and give it a workout. A temporary fix would be to run a hotter plug. When I started mowing with the CA after it sat for 20 years, it would foul number one about every hour of mowing. I put the next hotter plug in and ran it all season without a problem. Some of that was probably due to rings getting loosened up with work and sea foam though. ------------- http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF |
Posted By: MACK
Date Posted: 29 May 2012 at 10:05pm
| Check the air cleaner hose for a hole on bottom just behind carb. MACK |
Posted By: Steve in NJ
Date Posted: 29 May 2012 at 10:19pm
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Usually, backfiring in the muffler after the engine is shut down is unburned fuel expanding and igniting in the hot muffler. Usually caused by an over-rich or to fat of a fuel mix. Sometimes a sinking float could cause this situation. The plugs will tell the story most of the time. If you have a black oily film showing on the plugs, I would say it needs a valve job along with getting the guides re-done. Its loosing oil control somewhere in the engine. Could be a pretty worn set of rings as Tuck mentioned.... HTH Steve@B&B |
Posted By: KGood
Date Posted: 30 May 2012 at 6:36am
| 427 I know what your saying,but this was not fouling because of oil,we were running a MSD hot box with around 12/1 compression and 125 octane. They were NGK plugs it didn't matter if it was idling or not (usually happen at the pull). The high octane fuel is why we fouled acording to an oldtimer and he must have been right because colder plugs did the trick. |
Posted By: CTuckerNWIL
Date Posted: 30 May 2012 at 6:51am
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Along with what Steve said, I have experienced engines that backfire after shut down with having a leak in the manifold or gaskets. If you have glowing hot carbon build up and unburnt fuel, all you need is a little air to make an explosion. If it does have a small leak in the intake somewhere it could be compensated for by enriching the mixture, adding to the problem.
------------- http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF |
Posted By: KGood
Date Posted: 30 May 2012 at 10:32am
| Mack what you said. Is that something every D19 owner should check before it's to late and you have an oil burner? |
Posted By: captaindana
Date Posted: 30 May 2012 at 7:24pm
| My D19 occasionally would have some oily black junk on a couple of plugs, but after the past 2 years of running the baler it hasn't bothered. She also used to backfire really badly. I set the idle lower so when I push the throttle back to idle and hold the lever there it will quit and now it never backfires. To make her idle I just push throttle back to idle and not hold it there . Works perfect for me. When I ran avgas she really would backfire like my .264 Win Mag! lol |