Farm Equipment - Trouble timing the C

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Trouble timing the C

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=160196
Printed Date: 14 Apr 2026 at 8:13pm
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Topic: Trouble timing the C

Posted By: combinechris
Subject: Trouble timing the C
Date Posted: 19 Apr 2019 at 7:59pm

Been trying to get my C going. Can't seem to get the distributor timed right. First time had two cylinders firing and one backfired. Third attempt nothing fired only backfired.fourth time blew up coil. Considering putting a magneto on. What am I doing wrong. We took first plug out and got first piston to TDC then checked distributor still a no go.

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35 combines and 15 forage harvesters. mostly allis combines and equipment.WTB 2 row cornhead for a 90

Replies:

Posted By: WF owner
Date Posted: 19 Apr 2019 at 9:02pm

Do you have the wires on the cap in the right order (1-2-4-3)?

You say you have the piston at TDC. Is it at TDC on the compression stroke ? If not, timing is 180 degrees off.

Posted By: Gerald J.
Date Posted: 19 Apr 2019 at 9:10pm

Shop manual has details for that:

http://geraldj.networkiowa.com/Trees/Allis-Chalmers-G-B-C-CA-Service.pdf" rel="nofollow - http://geraldj.networkiowa.com/Trees/Allis-Chalmers-G-B-C-CA-Service.pdf

Gerald J.

Posted By: HoughMade
Date Posted: 19 Apr 2019 at 9:18pm

When at TDC, can you see the “Center” mark through the flywheel inspection hole?

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1951 B

Posted By: Jim.ME
Date Posted: 19 Apr 2019 at 9:44pm

Wires go clockwise around the cap.

Something else seems wrong when you say the coil blew up on the fourth try. I don't think I've seen a coil blow up because an engine is out of time. Check for a short in the distributor; grounded strap or wire, bad insulated terminal, bad condenser?

Posted By: Dick L
Date Posted: 20 Apr 2019 at 7:36am

When learning out how to time an engine with a distributor you need to get the number one cylinder at top dead center on the compression stroke. To be on the compression stroke both valves on the cylinder needs to be closed. Compression can not be built with one of the valves open. To keep from guessing you can remove the valve cover and make sure both rocker arms are up and has clearance between the rocker arm pad and the end of the valve stem. Check at this point for the TDC or CENTER line is in the inspection hole.

If you have a vertical distributor the number one wire terminal should be next to the engine block toward the radiator. The number two wire terminal will be toward the radiator away from the block. The number four plug wire will be away from the block toward the rear of the tractor. The number three plug wire will be toward the rear of the tractor close to the block.

When it is in this position remove the distributor cap. Loosen the hold down clamp from the base of the distributor with the rotor pointed toward number plug wire terminal and rotate the distributor back and fourth making sure the points are closed and just ready to open. I do this with the switch on so I can watch it spark when the points open. If the rotor does not point to the number one terminal the distributor will need to be lifted out and replace so the rotor does point to number one terminal. Remember the distributor gear is spiral and as you replace the distributor the rotor will rotate and you might need to lift it out to engage the correct gear teeth.
The tractor is now in time.

In doing this way you have proved that you are on the compression stroke at top dead center without guessing. You have also proved that it is ready to fire at top dead center without guessing.

The coil problem has nothing to do with the timing. Could be a 6 volt coil hooked to 12 volts with out the resister. In all my years I have never had a coil blow up.

Posted By: Dick L
Date Posted: 20 Apr 2019 at 8:11am

In addition to the above timing to number one cylinder the engine can be correctly timed anytime the TDC or CENTER line is in the inspection hole by removing the valve cover and checking which cylinder has both rocker arms up with clearance. Then making sure the points are about to open with the rotor pointing to that cylinder plug wire terminal.

In addition to that if you do not know the firing order you can find it in the same manor. Rotate the engine is at number one and marking it as 1. Make one revolution and mark the two rocker arms that are up with clearance will be 2. The next revolution with the rocker arms are up with clearance will be 3. The next one will be number 4. Watching this engine this way you would find your firing order for this engine would be 1-2-4-3.

Remembering that every time the TDC is in the inspection hole one of the pistons is up and ready to fire on this engine.