1937 BR Timing

FLAman

Member
I have a 37 BR SN# 327419. Just installed a rebuilt Wico XH477 magneto that I got from Brillman. This is the first change I've made to this tractor and it's my first JD 2 cylinder. I have the I&T and JD manuals. When I went to install the rebuilt mag the slots in the governor were not oriented the way the manuals said they should be. I also noticed that the mag I got from Brillman has the tag and the stop post on the opposite side of the XH477 I took off. When I hand crank the tractor it tries to start, takes the flywheel out of my hand, but that's it. I'm also hearing a gurgling sound when I pull the flywheel through, which I think is coming from the oil bath intake. All this is making me think I have a timing problem. I want to check if the flywheel is correctly mounted on the crankshaft. I'm not finding much about this in the manuals or online. So, how do I tell if the flywheel is mounted correctly?

Thanks,
Rick L.
 
Verify that the ^ marks stamped in the end of the crankshaft and by one of the splines in the flywheel are matched up.

The photo is of a "70" flywheel with a repair hub, but you can see the ^ mark in the end of the crankshaft, should be a matching one on the flywheel pointing at it.

<img src = "http://i108.photobucket.com/albums/n8/weirddeere/Taperlock.jpg">
 
Let's think about this.
1. Was the tractor running before you bought the new magneto?
2. Why did you need a new magneto?
3. Why would your flywheel be on wrong?
4. Do you know how to set the timing by the flywheel mark/gear case mark? If not, try #5.
5. Can you remove the left side spark plug and determine when the piston is at the top of the stroke? You can use a soda straw to feel the piston move up or down.
6. Mark the flywheel so you can return to this position. (later)
7. Look at the magneto drive slot. The grooves should be horizontal.
8. If the grooves are horizontal, install the magneto. (If not, might be other problems).
9. Prepare to start the engine.
10. If it does not fire or start, reverse your spark plug wires in the magneto. It should start.
11. This is how I would do it as simple as possible. There are other considerations in order to achieve perfection, but we are trying to get it to start, fine tuning can come later.
12. I currently own four two cylinder JD's A,B,G's, and these four are some of the smoothest running two-cylinders I have seen. I started driving and understanding two cylinders in 1949. Still trying and having fun.
 
Does it snap when it turns over? If not it may be set up for opposet direction. The R diesels used the different rotation on their starter motors. Ron MN
 

Yes, the tractor was running before I switch out the magneto. I had to replace the magneto because the drain hole in the bottom got plugged up and the magneto sat full of water for a period of time and would no longer produce a spark. I was going to rebuild it, but the cost of parts was almost as much as getting a rebuilt one from Brillman.

I am suspicious of the flywheel position because I had a hard time getting the LH Impulse mark to line up with the governor slots in the correct position. I don't know who worked on this tractor prior to me buying it. Also, it seemed to me like the best place to start to see if the mechanical timing was setup correctly.

I did have to reverse the plug wires to get it to spark the correct plug. Plug wires and plugs are also new. Plugs are Autolite 3076.

Thank you for the steps. I will go through them and see if I can get it going.
 

Yes, it snaps and produces a nice fat spark at the plugs. Plugs are gapped at .030.

Thanks for your reply,
Rick L.
 
When the flywheel is on the correct crankshaft spline and the LH flywheel impulse mark is lined up with the flat mark at 3 o clock on tractors side, the left piston should be at TDC and iffffffffff the crank to cam and cam to governor is timed correct the open slot in governor shaft end where mag mates should be flat horizontal fore n aft. Its more common to remove the clutch and NOT get it back in time then removing a flywheel and if its not in time it vibrates badly. Also if the governor was removed and NOT put back in time to the camshaft the open female slot where mag mates may NOT be flat horizontal FORE N AFT AS ORIGINAL which can make timing difficult.

If all well the mags impulse should trip right as the flywheels Left Hand Impulse passes the flat mark at 3 o clock.

John T
 
(quoted from post at 03:36:25 07/23/18) When the flywheel is on the correct crankshaft spline and the LH flywheel impulse mark is lined up with the flat mark at 3 o clock on tractors side, the left piston should be at TDC and iffffffffff the crank to cam and cam to governor is timed correct the open slot in governor shaft end where mag mates should be flat horizontal fore n aft. Its more common to remove the clutch and NOT get it back in time then removing a flywheel and if its not in time it vibrates badly. Also if the governor was removed and NOT put back in time to the camshaft the open female slot where mag mates may NOT be flat horizontal FORE N AFT AS ORIGINAL which can make timing difficult.

If all well the mags impulse should trip right as the flywheels Left Hand Impulse passes the flat mark at 3 o clock.

John T

What you are describing is exactly what I am concerned about.

Thanks,
Rick L.
 
"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">All this is making me think I have a timing problem.[/i:654c4848f0][/b:654c4848f0]</font>"

You might consider checking the timing on the No. 1 (flywheel side) cylinder.

To prevent the tractor from accidentally starting:

Remove the spark plug cable from the No. 2 spark plug.

a167964.jpg" width="650"


Make sure the gas is turned off.

Lock both brakes.

Transmission should be in neutral and the hand clutch should be disengaged.

This is one method of checking the timing.

Remove the No. 1 spark plug on the flywheel side.

a167965.jpg" width="650"


Place your finger over the hole and rotate the flywheel in the running direction (counter-clockwise) until you feel pressure (compression) of air in the cylinder.

Continue rotating the flywheel counter-clockwise slowly until the ?[b:654c4848f0][i:654c4848f0]L. H. IMPULSE[/i:654c4848f0][/b:654c4848f0]? mark on the flywheel lines up with the reference mark on the gear cover.

a167966.jpg" width="650"


Loosen the two cap screws securing the magneto.

Tap the top of the magneto toward the rear of the tractor a little at a time until the impulse trips.

a167967.jpg" width="650"


Tighten the cap screws and continue rotating the flywheel counter-clockwise until you see a spark at full pressure (compression) for No. 1 cylinder.

a167968.jpg" width="650"


Hope this helps.
 

Here's a pic of the flywheel. The only markings I see are what look to be two punch marks, one on the crank and one on the flywheel. I haven't had a chance to look into any of the other suggestions.

Thanks,
Rick L.


mvphoto20378.jpg
 

Just a quick update. I went out yesterday to work on this tractor, and I guess water got into more than just the magneto. The engine is stuck. Tried everything I know how to do to break it loose, but no luck. Filled it with Marvel Mystery oil and I'll keep trying to break it loose.

I'll come back when I can turn her over again.

Thanks,
Rick L.
 
Holy crap! Went from "won't start" to "froze up" in a hurry. Just a note, these things don't like to be left outside in the rain and snow.
Sorry to hear she's in a worse way.
 
(quoted from post at 14:20:19 08/06/18) Holy crap! Went from "won't start" to "froze up" in a hurry. Just a note, these things don't like to be left outside in the rain and snow.
Sorry to hear she's in a worse way.

So I am finding out. :cry: This also explains a continuous rear axle leak that's had me baffled for awhile. Obviously it is filling up with water every time it rains and is leaking out. Time to change all the fluids and get a tarp as well.

Thanks,
Rick L.
 

So, a week soaking in Marvel Mystery Oil and a little persuasion and I got 'er broke loose. Pulling the valve cover and using a boroscope I was able to find TDC on the compression stroke of the left cylinder. The governor mag slots were horizontal, so the mechanical timing appears to be correct. I timed the mag per the I&amp;T manual and the left cylinder is getting fire when it should. Started trying to get 'er to start and ran into two problems; the daily South Florida summer thunderstorms rolled in and the combustion chambers still have the Mystery oil in them. Next step is to get out my Mity Vac and get as much of the oil out of the combustion chambers as possible.

Thanks for all the tips, they really helped. I'll post an update once I get 'er running.

Thanks again,
Rick L.
 

Working on the BR again. Total newbie question, which is the exhaust valve on the left cylinder?

Thanks,
Rick L.
 
(quoted from post at 15:38:16 08/27/18)
Working on the BR again. Total newbie question, which is the exhaust valve on the left cylinder?

Thanks,
Rick L.

I figured out which was the exhaust valve. Still having the same issue. Tractor will pull the flywheel out of my hand trying to start, but never starts.

One thing that seemed kind of odd to me. When I timed the magneto using the I&amp;T manual instructions, the magneto ended up all the way forward. Is this my issue?

Thanks,
Rick L.
 

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