Re: Engine Problem

Wed Jun 25, 2014 10:43 pm

Thanks for the lesson on posting quotes. I never would have figured it out on my own. Can't wait to try it.

Re: Engine Problem

Thu Jun 26, 2014 9:49 am

Clownfish wrote:vacuum gauge Results are below.
Engine warm, mag grounded out with kill switch, and cranked over with the starter. Choke and throttle were closed and the idle air adjustment was closed:
Vacuum gage fluttered between 5 and 14 inches

Engine running at low idle, no choke and with idle air adjustment closed:
Gage flutters between 13.5 and 15 inches

Engine at ½ throttle and ¾ choke:
Gage steady at 8.5 inches—More or less choke engine dies.


http://www.freeasestudyguides.com/engin ... -test.html

Re: Engine Problem

Sat Jun 28, 2014 12:01 am

Today I received a combo Timing Light/Tacometer. I connected it to a 12V battery and the No. 1 plug wire. I could get the idle down only to about 500 rpm and at that point I checked the timing. My pulley has only one notch and I painted this notch white. The timing light showed this notch about 1 1/2 inches below the pointer when standing on the left side of the tractor. That is putting the notch past the pointer when it fires. Since the mark is past the pointer does this mean that the firing is After TDC rather than Before TDC? When I press the button marked ADVANCE on the Timing Light until the reading in the "ADVANCE DISPLAY window" reaches about 13. Continuing to press this button raising this number above 13 moves the white mark down and away from the pointer more with each degree of advance . Does this look correct? When I advanced the engine speed up to about 1000 rpm the white mark stayed in about the same location with just a slight mount of movement.

Another item related to the ignition: The new plug wires that I have appear to be "stranded" copper wire rather than "solid" copper wire as I have seen recommended. I can see individual strands at the ends. When checking individual plugs with a spark tester (light connected between dist cap and plug) I get a strong flash when the plug fires and a very faint flash of the light when each of the other plugs fire. This is using the hand crank. This extra flash is very weak and you have to be inside with all lights off to see it. I am assuming that this flash comes from wire to wire leakage. Without the test light I don't see sparks jumping from the wires as I have seen on old cars with old wires.
For this testing I have disconnected the linkage between the governor and carb and am controlling everything by hand. I did this just to remove the governor from the equation. With no load I assume that I should be able to maintain a steady RPM by adjusting the throttle setting by hand. I have never used the spark tester in the dark before so I do not know if this additional weak flash is normal.

I am not sure how to interpret the info above. Any suggestions?

Glenn

Re: Engine Problem

Sat Jun 28, 2014 7:42 am

Since the mark is past the pointer does this mean that the firing is After TDC rather than Before TDC?
Engine crankshaft, pulley with notch, rotates clockwise.

Before TDC means the pulley notch is prior to the pointer. TDC means the notch lines up with the pointer. After TDC means that the notch has rotated past the pointer.

Re: Engine Problem

Sat Jun 28, 2014 9:01 am

your new wires are correct (stranded copper)

Re: Engine Problem

Sat Jun 28, 2014 9:43 am

Vacuum readings are too low based on satisfactory compression readings. This suggests a vacuum leak (manifold gasket), late (retarded) ignition or valve timing.

Re: Engine Problem

Sat Jun 28, 2014 10:41 am

Eugene wrote:
Since the mark is past the pointer does this mean that the firing is After TDC rather than Before TDC?
Engine crankshaft, pulley with notch, rotates clockwise.

Before TDC means the pulley notch is prior to the pointer. TDC means the notch lines up with the pointer. After TDC means that the notch has rotated past the pointer.


Since the pulley notch is past the pointer by about 1.5 inches does this mean that the timing is at about 10 degrees After TDC rather than the spec of 13 degrees Before TDC and the timing is off by 30 degrees?

Glenn

Re: Engine Problem

Sat Jun 28, 2014 11:14 am

Clownfish wrote:10 degrees After TDC rather than the spec of 13 degrees Before TDC and the timing is off by 30 degrees?
23 degrees.

An ignition timing issue, did you get the governor installed correctly to the idler gear?

Re: Engine Problem

Sat Jun 28, 2014 11:21 am

Eugene, Would this be an indication that when the machine shop reassembled the engine, the internal timing was off?

Bob

Re: Engine Problem

Sat Jun 28, 2014 11:32 am

Bob McCarty wrote:Eugene, Would this be an indication that when the machine shop reassembled the engine, the internal timing was off?Bob
That's a possibility but I don't think so since engine runs. First place to check is the idler gear to governor gear timing. If this were my tractor and I couldn't see the timing marks, I would pull the seal. A lot easier than pulling the engine front cover.

Machine shops usually have experienced mechanics. Kinda hard to mess up the idler gear timing since the marks face the front of the block. The idler gear to governor gear is another issue since timing marks are on the back side, towards the magneto.

One tooth off on the governor drive gear installation is 20 degrees. That's pretty close to the 23 degrees variance is the spark timing.

Re: Engine Problem

Sat Jun 28, 2014 11:31 pm

As I have mentioned earlier in this thread I was not sure that I did not get the governor installed 1 tooth off and now as it looks more and more likely that timing is my problem I am convinced that the installation of the governor may be the problem. What I don't understand is how the governor can be installed incorrectly and still have No 1 Plug fire just as the no 1 piston reaches TDC when hand cranking. I don't doubt that it can happen --I just don't understand how. I have seen the plug fire right at TDC as indicated by the notch on the pulley lining up with the pointer at the same time as the plug fired. I also confirmed that it was on the compression stroke. Is there any way for the incorrect installation of the governor to cause the notch and the pointer to line up at any time other than TDC? As you can see I am not very knowledgeable about the fine details of this process. I am hoping to learn enough so that the next time I go through this process I can figure out how to get it right.

Another question I have is--When I rotate the top of the installed Magneto back away from the engine is the timing being or retarded? I am assuming that I am advancing it.

Glenn

Re: Engine Problem

Sun Jun 29, 2014 3:15 pm

Clownfish wrote:Since the pulley notch is past the pointer by about 1.5 inches does this mean that the timing is at about 10 degrees After TDC rather than the spec of 13 degrees Before TDC and the timing is off by 30 degrees?
Clownfish wrote:What I don't understand is how the governor can be installed incorrectly and still have No 1 Plug fire just as the no 1 piston reaches TDC when hand cranking.
The J4 magneto has two positions at which it fires; 0 degrees and 13 degrees advance.

Based upon the top post, the magneto is not firing at #1 cylinder TDC when hand cranking the engine but some place after TDC.

Get some one to help. Timing light, hand crank engine, double check spark location hand cranking. You can rotate the magneto through it's maximum range to watch the spark location move.

Re: Engine Problem

Sun Jun 29, 2014 9:19 pm

Eugene wrote:
Clownfish wrote:Since the pulley notch is past the pointer by about 1.5 inches does this mean that the timing is at about 10 degrees After TDC rather than the spec of 13 degrees Before TDC and the timing is off by 30 degrees?
Clownfish wrote:What I don't understand is how the governor can be installed incorrectly and still have No 1 Plug fire just as the no 1 piston reaches TDC when hand cranking.
The J4 magneto has two positions at which it fires; 0 degrees and 13 degrees advance.

Based upon the top post, the magneto is not firing at #1 cylinder TDC when hand cranking the engine but some place after TDC.

Get some one to help. Timing light, hand crank engine, double check spark location hand cranking. You can rotate the magneto through it's maximum range to watch the spark location move.



I have posted so much info on this problem that it probably has become confusing. My current situation is:
I static timed the tractor and when I slowly hand crank, I now hear the "Click" from the magneto just as the notch on the pulley aligns with the pointer. I put a spark test light between the No 1 plug and the Dist and I get a flash of the light just as I hear the click. In order to get the flash of the light I have to hand crank it with some speed, so I cannot see exactly where the notch is when I get the flash but it is at the same time as I hear the click.

Using the timing light the notch on the pulley is below the pointer by about 1.5 inches with the engine running at about 550 rpm. At about 1600 RPM, which I can only reach by using a lot of choke, using the timing light the notch moves up nearer the pointer by a small amount.

I tried using the timing light while hand cranking but I do not get a flash from the light when hand cranking. I did get a flash with the spark test light when hand cranking. Should I be getting a flash from the timing light while hand cranking?

With the engine running at about 550 rpm I rotated the top of the magneto as far away from the engine as it would go. This moved the notch to about 1/2 inch below the pointer. At 1600 RPM the notch bounces around a lot and it is not even visible for about 1/2 sec, every 2 or 3 sec. I don't know if the timing is changing during this time or if the plug isn't firing. There doesn't appear to be any break in the rhythm of the flashes. Also I inserted the spark test light and it showed no interruption in the firing. Could this mean that my magneto/distributor is not operating correctly?

Question: Is the spark going to the plug exactly when you hear the click from the magneto when you are static timing ? If this is so, does this mean that I am correctly timed when, while slowly hand cranking, the click is exactly when the notch aligns with the pointer? With this condition is it still possible that the governor is installed incorrectly-- maybe off by a tooth? I have ordered a new gasket and will be ready to remove the governor and try again to install it correctly if this is the likely problem.

Glenn

Re: Engine Problem

Sun Jun 29, 2014 9:42 pm

PM sent...

Re: Engine Problem

Mon Jun 30, 2014 5:34 am

Let me take a stab at some of this, not being there in person, it is not easy to fully comprehend.

I have posted so much info on this problem that it probably has become confusing. My current situation is:
I static timed the tractor and when I slowly hand crank, I now hear the "Click" from the magneto just as the notch on the pulley aligns with the pointer. I put a spark test light between the No 1 plug and the Dist and I get a flash of the light just as I hear the click. In order to get the flash of the light I have to hand crank it with some speed, so I cannot see exactly where the notch is when I get the flash but it is at the same time as I hear the click.


Okay, the magneto is set to a standard of 13 degrees advance. When the impulse coupling is engaged, it is RETARDING the magneto for hand cranking, and to cause the magneto to spin faster when producing the spark (hotter spark). Once the engine is running, the impulse coupling drops out, so you are back to 13 degrees advance. What I didn't understand in your earlier post is that you advanced the timing light to 13 degrees, but you didn't say that aligned the spark with the pointer. In fact, being below the pointer indicates retarded timing.

Using the timing light the notch on the pulley is below the pointer by about 1.5 inches with the engine running at about 550 rpm. At about 1600 RPM, which I can only reach by using a lot of choke, using the timing light the notch moves up nearer the pointer by a small amount.


between 550 and 1600 rpm, there would be no real movement of the timing; the impulse is no longer engaged at either speed, so you have 13 degrees advance built into the magneto.

I tried using the timing light while hand cranking but I do not get a flash from the light when hand cranking. I did get a flash with the spark test light when hand cranking. Should I be getting a flash from the timing light while hand cranking?


You should get a spark (flash of light) right when the impulse clicks.

With the engine running at about 550 rpm I rotated the top of the magneto as far away from the engine as it would go. This moved the notch to about 1/2 inch below the pointer. At 1600 RPM the notch bounces around a lot and it is not even visible for about 1/2 sec, every 2 or 3 sec. I don't know if the timing is changing during this time or if the plug isn't firing. There doesn't appear to be any break in the rhythm of the flashes. Also I inserted the spark test light and it showed no interruption in the firing. Could this mean that my magneto/distributor is not operating correctly?


Moving the magneto away from the engine is advancing it, as evidenced buy your notch starting at 1.5", and then moving to 0.5". However, your timing is still retarded.No pun intended.

Question: Is the spark going to the plug exactly when you hear the click from the magneto when you are static timing ? If this is so, does this mean that I am correctly timed when, while slowly hand cranking, the click is exactly when the notch aligns with the pointer? With this condition is it still possible that the governor is installed incorrectly-- maybe off by a tooth? I have ordered a new gasket and will be ready to remove the governor and try again to install it correctly if this is the likely problem.


The answer to your questions are yes. The spark is sent when the impulse coupling releases the magneto (the click); however, that coupling has some strong springs in it, so I have seen them actually move the engine past the notch just a hair, making it difficult to be real precise. This is why, to static set the timing, you set the pointer to align with the notch, then rotate the magneto away from the engine block SLOWLY just until the click. If you look at that point, your notch may have ticked just a hair past the pointer, due to the magneto spring. Sometimes, I will "back up" the mag just a hair from where it "clicked" to compensate. A "hair" is a scientific measure here.

I think your governor is off a tooth, but I also think your distributor cap may be allowing the spark to arc across all the wires. I don't believe your "northern lights" description to be normal. If you haven't replaced the cap, give it a try. Or at least clean the inside and look for possible arcing. Also, retime your magneto to the governor, or governor to the engine. Lastly, make sure the rotor and pinion inside the magneto are timed correctly to one another, using the marks.

Best of Luck!

Edited for some typing errors, content unchanged