D14 on 3 cylinders

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Hello!  I just joined this forum...   I think I used it years ago. I just purchased a partially restored D14, which almost runs good. After a day or two of playing with it, I finally pulled the #4 spark plug wire while it was running, and it sounded the same: as if it was running on 3 cylinders. Compression check of #s 4 and 3 cylinder were 125#. After switching plugs, wires, etc, I pulled the valve cover, and the #4 exhaust valve spring is weakened to the point I can push the valve down 1/2 way with my thumb, something I can't do with any of the other valves. Lash was still about .015" as th IT book says. The spring itself is deformed, some coils closer than others. Is this causing the #4 cylinder not to fire? It has good spark (using the old screwdriver in the plug wire to block test) and good compression. Is the loose spring allowing blowby not detected by the compression test?   I grew up with a WD45 on a ranch, rebuilt that engine a couple times, plus some V-8s, Volkswagens, transmissions-  but that was years ago. This D14 needs some more of that, but I thought I'd throw this out. I think the head has to come off to get the best look...
Thanks!Tom

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tlokimer Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 02 Oct 2011 Points: 4	Post Options Post Reply Quote tlokimer Report Post Thanks(0) Quote Reply Topic: D14 on 3 cylinders Posted: 02 Oct 2011 at 12:26pm
	Hello! I just joined this forum... I think I used it years ago. I just purchased a partially restored D14, which almost runs good. After a day or two of playing with it, I finally pulled the #4 spark plug wire while it was running, and it sounded the same: as if it was running on 3 cylinders. Compression check of #s 4 and 3 cylinder were 125#. After switching plugs, wires, etc, I pulled the valve cover, and the #4 exhaust valve spring is weakened to the point I can push the valve down 1/2 way with my thumb, something I can't do with any of the other valves. Lash was still about .015" as th IT book says. The spring itself is deformed, some coils closer than others. Is this causing the #4 cylinder not to fire? It has good spark (using the old screwdriver in the plug wire to block test) and good compression. Is the loose spring allowing blowby not detected by the compression test? I grew up with a WD45 on a ranch, rebuilt that engine a couple times, plus some V-8s, Volkswagens, transmissions- but that was years ago. This D14 needs some more of that, but I thought I'd throw this out. I think the head has to come off to get the best look... Thanks!Tom

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Chalmersbob Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 11 Sep 2009 Location: Pennsylvania Points: 2122	Post Options Post Reply Quote Chalmersbob Report Post Thanks(0) Quote Reply Posted: 02 Oct 2011 at 8:51pm
	A broken or weak valve spring would definetely cause a misfire. I don't know how you could get a good compression reading with it that way. You can get an adapter to screw into the spark plug hole and attach an air hose to pressurize the cylinder so you can pull the spring off and replace it withou removing the head. Bob

Chalmersbob Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 11 Sep 2009 Location: Pennsylvania Points: 2122	Post Options Post Reply Quote Chalmersbob Report Post Thanks(0) Quote Reply Posted: 02 Oct 2011 at 8:53pm
	OH!! I sorry, WELCOME to the forum. Bob

Orange Blood Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 29 Nov 2010 Location: ColoradoSprings Points: 4053	Post Options Post Reply Quote Orange Blood Report Post Thanks(0) Quote Reply Posted: 02 Oct 2011 at 9:01pm
	I agree with bob, that the compressed air is the way to go, just make sure you don't over preassure the cylinder, and the engine will rotate. Make sure the ignition is off, and what I do it lock the brakes, block the tires really well, and put it is high gear, with the affected piston at TDC, so if the seal is broken and the vavle drops, it will not drop into the cylinder and then you have to remove the head. Probably what is happening to cause good numbers on the test, is the engine is moving at a much slower speed than when it is running, allowing the valve to seat in about the time needed, when running on the other hand it's just not getting closed fast enough. I will be this is the problem, replace the spring and try it out.
	Still in use: HD7 WC C CA WD 2-WD45 WD45LP WD45D D14 3-D17 D17LP 2-D19D D19LP 190XTD 190XTLP 720 D21 220 7020 7030 7040 7045 3-7060 Projects: 3-U UC 2-G 2-B 2-C CA 7-WC RC WDLP WF D14 D21 210 7045 N7

Tracy Martin TN Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 11 Sep 2009 Location: Gallatin,TN Points: 10829	Post Options Post Reply Quote Tracy Martin TN Report Post Thanks(0) Quote Reply Posted: 02 Oct 2011 at 11:04pm
	You can take the plugs out of all the cylinders, unhook the battery, use a small rope and push it into the affected cylinder. Leave plenty sticking out. Turn engine over by hand untill the rope holds engine from turning. Valves will be held in place this way. The most important thing at the point, is don't break the rocker arm supports.It is best to relieve the pressure from each rocker arm at this point. Some will say you can just loosen the supports and re tighten only them. Might get by with that, might not. The supports are expensive to replace. Take your time and replace spring. The keepers are a pain without help or a valve spring compressor. Adjust all the valves after replacing spring. Buy the cork gasket, rubber ones will leak sooner. Enjoy your tractor. HTH Tracy Martin
	No greater gift than healthy grandkids!

tlokimer Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 02 Oct 2011 Points: 4	Post Options Post Reply Quote tlokimer Report Post Thanks(0) Quote Reply Posted: 04 Oct 2011 at 1:21pm
	Thanks! Everybody.... I'm on phone answering 'cause my Internet service is down. I'll try your ideas with all due caution. I've ordered a valve spring and head gasket. Will try to change the spring without pulling the head, with your good ideas, and keep you posted. Winter's coming & I hope get a loader fitted. Last year here was tough. Thanks again!!! Tom