Valve timing issues

[nutsoverJD]

Is the camshaft for an early model B pre-201000 The same as late model B all fuel after 201000. The reason for this question is I checked everything I can and the valve timing isn't correct. I check crank to cam timing marks. I watch the valve opening and closing exhaust seems to open late past BDC. The intake opens close to TDC and is still open on the compression stroke for a short time. My manual says to check timing and make adjustments by lifting cam gear and turning the fly wheel to LHEO mark and set back on the crank. I have attempted that but doesn't seem correct either.

 

[Mike(NEOhio)]

Seems like you're really hung up on this timing issue. Intake and exhaust opening and closing are almost never exactly are TDC and BDC. There's always some overlap which helps with exhaust scavenging and intake. Where are you checking the crank to cam timing? The gears are marked on the inside so you have to take off the crankcase cover, and where the gears are marked is not at TDC.

 

[nutsoverJD]

I have done that. Why then do I have popping out my intake while trying to start my tractor? That tells me the timing is off. I watch my intake valve closing on compression, it is open on the up stroke. I set my mag according to the manual at TDC

 

[MSD]

I have done that. Why then do I have popping out my intake while trying to start my tractor? That tells me the timing is off. I watch my intake valve closing on compression, it is open on the up stroke. I set my mag according to the manual at TDC

You could have a leaking valve that would cause that. Turn over so that both the intake and exhaust valves are closed on one cylinder and put an air hose in the spark plug hole. You'll have to figure out how to seal it. Listen by the valves and see if there is an air leak coming from them. If not turn over and do the other side.

 

[Mike(NEOhio)]

I don't get "my intake valve closing on compression, it is open on the up stroke". Did you ever find the flywheel to crank marks like I described?

 

[ET]

The cam to crankshaft timing marks are on the inside of the cam gear. The mark on the crankshaft is almost covered by the crank throw and can be very hard to see.

 

[used red MN]

I don't get "my intake valve closing on compression, it is open on the up stroke". Did you ever find the flywheel to crank marks like I described?

Mike or other JD two cylinder guys, okay again playing the field just trying to help. In his other thread linked here Previous JD B No start thread in reply 13 you asked him why he was concerned with the counter weight positions. It seems like the counter weight position can verify the flywheel is installed correctly. Watch this video. JD letter series timing video At 1:15 he explains the cam timing mark alignment and then at 6:00 he explains the flywheel counter weight position and later the drive clutch counter weight position. Comments on that? Do you agree? I would think if he had them wrong it would shake like a nervous mule.
The OP claims he verified the number one piston was at TDC and the flywheel counter weight is at 3 o’clock which would seem to indicate his flywheel is on correct. Leaking valves or not as mentioned by MSD had not been verified one way or the other yet.

 

[TSK]

Popping out your intake…..make sure the plug wires are not switched.

 

[Mike(NEOhio)]

Mike or other JD two cylinder guys, okay again playing the field just trying to help. In his other thread linked here Previous JD B No start thread in reply 13 you asked him why he was concerned with the counter weight positions. It seems like the counter weight position can verify the flywheel is installed correctly. Watch this video. JD letter series timing video At 1:15 he explains the cam timing mark alignment and then at 6:00 he explains the flywheel counter weight position and later the drive clutch counter weight position. Comments on that? Do you agree? I would think if he had them wrong it would shake like a nervous mule.
The OP claims he verified the number one piston was at TDC and the flywheel counter weight is at 3 o’clock which would seem to indicate his flywheel is on correct. Leaking valves or not as mentioned by MSD had not been verified one way or the other yet.

That video is a hand start earlier model. The info I was giving him is based on my late A and 41 H. Neither has the rivet on the crank and the flywheel can go on anywhere. He seems like a new JD owner has the later B.

 

[Mike(NEOhio)]

Pictures of my H crankshaft and flywheel and timing marks on the A. Camera angle is off so the cam gear is actually more to the upper right but you can see the position of the crank throw. It's actually toward the lower left.

 

[nutsoverJD]

I will check all this information. I have verified my crank and cam timing several times. I'm thinking I'm not installing the Mag correctly. I line up my gov marks and the mag drive is horizontal. However, I'm not positive on the LH at TDC. My manual (after reading several times) says to install gov at TDC. Nothing about lining up timing marks in the gov just make sure mag drive is horizontal.

 

[MSD]

Have you checked the valve clearances yet? That could cause it also.

 

[used red MN]

Have you checked the valve clearances yet? That could cause it also.

He originally posted here on YT his first time in the Restoration Processes forum.
This is what he said there.
..”I have been trying to start my grandsons B (he is one years old). I have checked all timing marks from gov to crank. all is good. there is 110 psi compression in both cyl. I checked valve lash and readjusted as needed (wasn't off much). I have a 25degree mag.in it. it is an all-fuel machine. Do I need a 35degree mag? Had it running twice for a short time. Seems to have good spark I cleaned the Carb. Tried either and it will backfire to the intake. I moved the mag some both directions didn't help. Any suggestions will be appreciated. I will buy new plugs, what do you recommend there is champion D21 in there now.“..
Here is a link to that thread.
Original post on issue I suggested he try posting a thread here that thread is linked in my reply 13
above.
Says he has had it running twice for a short time. Above he says the valves were adjusted and 110 psi compression in both cylinders.
I would like to see some pictures of it all. For one I would be curious to see the spark plugs. Plugs fouled with black rich mixture soot don’t fire very well. Just a hunch.

 

[Mike(NEOhio)]

I will check all this information. I have verified my crank and cam timing several times. I'm thinking I'm not installing the Mag correctly. I line up my gov marks and the mag drive is horizontal. However, I'm not positive on the LH at TDC. My manual (after reading several times) says to install gov at TDC. Nothing about lining up timing marks in the gov just make sure mag drive is horizontal.

I was thinking it's your mag today, too, so I got my H mag, Wico X. All letter series use the same one. It could have been assembled wrong in the impulse coupling. A you turn it the rotor shaft will stop with the rotor V up and the lugs will be bout 20 degrees past vertical and you will feel the spring loading up. When the lugs hit horizontal the coupling trips and first arm will pass the upper terminal firing #1 and the V will stop about 4-5 o'clock. Another half turn of the coupling loads up and trips for the second arm to fire the lower terminal. Next half turn it goes back to the top. When you set #1 to TDC and drive slots horizontal, set the mag with the V up and turn the whole mag forward enough the get the lugs into the slots and seated to the gov. Then rotate the mag to rear till you hear it trip. I can make you a little video of the mag action if need be.

 

[Mark-Ia]

Forget about the timing marks, if the drive lug is horizontal install the mag, if it backfires or pops back through the carb, switch the wires.

 

[nutsoverJD]

thank you I will try what you suggested Mike(NEOhio)

I was thinking it's your mag today, too, so I got my H mag, Wico X. All letter series use the same one. It could have been assembled wrong in the impulse coupling. A you turn it the rotor shaft will stop with the rotor V up and the lugs will be bout 20 degrees past vertical and you will feel the spring loading up. When the lugs hit horizontal the coupling trips and first arm will pass the upper terminal firing #1 and the V will stop about 4-5 o'clock. Another half turn of the coupling loads up and trips for the second arm to fire the lower terminal. Next half turn it goes back to the top. When you set #1 to TDC and drive slots horizontal, set the mag with the V up and turn the whole mag forward enough the get the lugs into the slots and seated to the gov. Then rotate the mag to rear till you hear it trip. I can make you a little video of the mag action if need be.

I checked my mag as you suggested. I took pictures, my first pic is rotor position before my first trip drive lugs are horizontal after tripping. Second is rotor position after tripping.

I was

thinking it's your mag today, too, so I got my H mag, Wico X. All letter series use the same one. It could have been assembled wrong in the impulse coupling. A you turn it the rotor shaft will stop with the rotor V up and the lugs will be bout 20 degrees past vertical and you will feel the spring loading up. When the lugs hit horizontal the coupling trips and first arm will pass the upper terminal firing #1 and the V will stop about 4-5 o'clock. Another half turn of the coupling loads up and trips for the second arm to fire the lower terminal. Next half turn it goes back to the top. When you set #1 to TDC and drive slots horizontal, set the mag with the V up and turn the whole mag forward enough the get the lugs into the slots and seated to the gov. Then rotate the mag to rear till you hear it trip. I can make you a little video of the mag action if need be.

 

[Mike(NEOhio)]

thank you I will try what you suggested Mike(NEOhio)

I checked my mag as you suggested. I took pictures, my first pic is rotor position before my first trip drive lugs are horizontal after tripping. Second is rotor position after tripping.

That looks right. Second pic the rotor has already fired the upper terminal. It should have tripped when the lug were horizontal. If you continue turning the coupling another half turn, till horizontal again the second arm of the rotor should end up just below the lower terminal. That would be 180 degrees on the crank and #2 at TDC.

 

[nutsoverJD]

OK I was thinking the V between the terminals should be more vertical. thank you for clarifying

 

[nutsoverJD]

I checked my valve position. in all phases on the stroke. My RH TDC intake valve is slightly open (waste spark) when LH is on compression stroke TDC. The RH when on compression stroke at TDC the LH TDC (waste spark) intake valve is closed. Anyone with an explanation on why that would be?

 

[a49deere]

Where are your valves located when you put your finger over #1 cylinder (LH cylinder) when you roll engine over (By hand) and start to feel compression and then continue that piston to the top of that stroke, not going further than TDC. Now, this may seem like a rather stupid question and by no means an insult, you are aware that #1 cylinder is the one on the left when looking from the seat, Correct? When that cylinder is on its compression stroke, verified by pressure build on your finger(It may actually be hard to feel because of slow speed turning by hand), I like to take a piece of tie wire bent at a 90Deg angle and insert into cylinder, watch as wire moves out of cylinder until obviously piston is at top of its stroke. where are your valves now on that cylinder?