Farm Equipment - Sticking valve wd 45

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Sticking valve wd 45

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=201376
Printed Date: 26 Jun 2024 at 2:53am
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Topic: Sticking valve wd 45

Posted By: dr p
Subject: Sticking valve wd 45
Date Posted: 17 May 2024 at 5:48pm

Tractor is running rough with a "pop" that is irregular. Tractor is fouling plugs way too easily. Changed coil, different carb drained and cleaned fuel tank, double checked timing. Tractor has electronic igition. It occured to me (during a bunch of boring silver fillings) that the valves may be sticking. The tractor had a recent (200 hours) complete engine rebuild. If it is sticky valves, could i pull the head and clean the valves ?

Replies:

Posted By: DrAllis
Date Posted: 17 May 2024 at 5:56pm

Valve lash to be set at .015" COLD intake and exhaust. Remove all the spark plugs and run a good compression test. Throttle wide open and a battery charger on the battery. If you have valves sticking (which I doubt) the compression test will reveal it. 200 hrs on an OH the compression should be perfect between all the cylinders, like 120-120-120-120.

Posted By: PaulB
Date Posted: 17 May 2024 at 7:05pm

I've encountered many automotive shops that get the valve guide to valve stem clearance too tight. That with valve stem seals make valves stick just after doing a valve job.

I never put seals on the exhaust valves when I do tractor heads.

DrP: You might just pull the valve cover first and see what you have. Find the one that's sticking and lubricate it liberally and work it up and down.

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If it was fun to pull in LOW gear, I could have a John Deere.
If you can't make it GO... make it SHINY

Posted By: dr p
Date Posted: 17 May 2024 at 7:55pm

So doc, what do you think it is?

Posted By: DrAllis
Date Posted: 17 May 2024 at 7:57pm

You do what you want. A well performed compression test will verify valve problems or not. A-C engines never used valve seals on the guides, altho some people put them on anyway.

Posted By: dr p
Date Posted: 17 May 2024 at 7:59pm

Sorry

Posted By: Steve in NJ
Date Posted: 18 May 2024 at 6:17am

Joseppie,

I would first check the firing order to make sure you don't have a wire crossed. Do the simple checks first. A simple crossed wire will foul a couple plugs. If that checks out okay, lift the valve cover and check valve lash cold like Doc Allis said. You might just simply have a tight valve or two. Is the popping on the intake side or is it popping in the exhaust? When I first started my WF after its resto, I had a popping in the exhaust every once in a while with a rough idle. I had to tight an exhaust valve on #3. Went through all the valves the following day after cool down and found two more that were a tick on the tight side. Put it back together and it run nice n' smooth. Much better throttle response as well.... 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

Posted By: dr p
Date Posted: 18 May 2024 at 5:21pm

Well all four cylinders were between 120 and 130 so i was wrong about the stuck valve. The clearance on a bunch of the valves were tighter than a rch so adjusted them back to 014 cold. Opened up the fuel screw a half turn. It still isn't perfect i set the timing by ear. Going to borrow a timing light and see if that gets her to 100%

Posted By: DrAllis
Date Posted: 18 May 2024 at 6:28pm

Retighten all your manifold bolts when the engine is COLD to be sure there's not a vaccum leak.

Posted By: Boss Man
Date Posted: 19 May 2024 at 5:33pm

Could be a bad spark plug wire arcing out/ shorting across. Electronic ignition requires higher quality wires for the higher voltage

Posted By: dr p
Date Posted: 19 May 2024 at 5:39pm

I think it was a lot of little things. Probably older gas, a carburetor that needed a more careful cleaning. The valves were certainly an issue, and the manifold bolts weren't at 20 foot pounds any more. Got a full afternoon of plowing in. Think some dental patients are going to get rescheduled this week. Thank you doc, steve, paul and bossman for helping