Wico X start timing

[Erik B]

I can't find any details on start timing in the service manual (pertaining to a '48B), apart from a minimal mention of it (I have the JD 96000-and up B and the IT service manuals). There have been a few posts here about it, and I have Duane Larson's article. Nothing seems to have pictures or detail a starting point for the mag. inside ring setting, and it has to be removed to make any adjustments. I've already set the run timing to 25 deg. BTDC, and since doing so, the B starts really hard. Duane's article details a procedure, but he says it's for the Wico C and XH, which I don't have.

My Wico X has the 6274 cup, which is also stamped "25 degrees." Duane's article on mag timing states that the markings on the inner timing ring are worth 5 degrees apiece. Mine is set for two major divisions west of due north, a.k.a. four minor divisions. I do not know where the run timing was set before I changed it.

Is due north on the inside timing ring of the mag 0 degrees, TDC, subject to run timing advances? So in other words, if I want start timing at 0 degrees, TDC, do I need to set the start timing ring at -25 degrees to compensate for my run timing adjustments already made?

And as to specifics of the start timing ring, if you have the mag off and you're looking at the ring, is west advanced or retarded, relative to run timing (or relative to rotation, run timing aside)?

I know John T directed me to the manual on one recent post for details on start timing, but unless I've missed something, I have all the relevant manuals, and don't see anything detailing that setting.

 

[jd b puller]

You want the mag to "impulse" or click when you are at TDC. The timing is essentially "fixed" at 25 degrees advance. put it on the tractor with both plugs removed. Roll the engine over slowly. The thing should fire when the "LH IMPULSE" mark on the flywheel lines up with the raised bump on the trans housing. If it's really close to that, just rotate the mag forward to retard or backwards to advance. If you're off a ways, pull it off and loosen the 4 screws that hold the cup. Move it a click and put it back on. You should figure it out withing a couple on and offs.

 

[34gpa]

eric,x and xh same thing. your marks should align on the second from the clear left or about 11 o clock as you look at it from the back.
follow everything that duane said and you will get it

 

[Erik B]

Happy to report, before looking at the replies, I decided to experiment. I moved the pointer to straight north, bolted it back on, and tried it.

Started faster and easier than it has since I bought it (and it used to pop off very fast), so I think I"ve got it. I double-checked the run timing with a timing light, still right on at 25 degrees BTDC.

 

[Bob Gauntt]

The mark at the twelve o clock position on the mag case is thirteen degrees and each mark is five degrees. If you set the mark on the striker plate two and a half marks to the left of the center mark on the mag case you should have the impulse set at twenty five degrees.

 

[Kemper]

If you need anymore info,here is Duane Larsons instructions for timing magnetos,he sent me this one time when i was having trouble with my A.


http://jd2cylservice.com/Misc14MagnetoTiming.pdf

 

[John T]

Hey there Erik, its high time we got that old girl up n runnin, there appears to be some MIS INFORMATION below so Im gonna try n get the record set straight (to best of my current knowledge, see PS below) once n for all, here goes.

1) For a review and definitions take a re read of my previous Wico Timing 101 post.

http://www.ytmag.com/cgi-bin/viewit.cgi?bd=rrtips&th=18619


2) Now lets take your questions one at a time;

a) My Wico X has the 6274 cup, which is also stamped "25 degrees." Duane's article on mag timing states that the markings on the inner timing ring are worth 5 degrees apiece.

TRUE (marks = 5 degrees BUTTTTTT see below)

b) Mine is set for two major divisions west of due north, a.k.a.

THAT SETTING IS WRONG AS RAIN for a lag angle of 25 which is what you need !!!! Sure, those marks are 5 degrees each as Duane said

BUTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT

For drive cups OTHER THEN 6274, straight up = 12/12 of Lag Angle (so 2 1/2 to West left of up = 25 lag angle) HOWEVER on the 6274 cup straight up only = 3 of Lag Angle

THAT 6274 CUP NEEDS SET ABOUT 4 1/4 (21 1/4 + 3 = just shy of 25) to West left of straight up for a lag angle of near 25 degrees


c) I do not know where the run timing was set before I changed it.

Changing the Lag Angle there in the rear by loosening n rotating the stop plate DOES NOT CHANGE OR AFFECT THE RUN TIMING it ONLY changes the start/impulse timing. Rotation of the mag in the govenor flange changes BOTH start and run timing

d) Is due north on the inside timing ring of the mag 0 degrees, TDC, subject to run timing advances?

Due North straight up = 12 1/2 lag angle for all cups OTHER THEN 6274 cup, in which straight up North = 3 lag angle

e) So in other words, if I want start timing at 0 degrees, TDC, do I need to set the start timing ring at -25 degrees to compensate for my run timing adjustments already made?

If you want start/impulse timing at TDC, (which is correct) your initial adjustment consists of setting the lag angle at 25 if you use a 25 advance 6274 drive cup WHICH MEANS 4 1/2 to left West of straght up for a 6274 drive cup. Then install mag straight up n down in govenor flange n see if she snaps at TDC, if NOT you gotta EITHER rotate mag in flange to adjust ORRRRRR remove mag n adjust stop plate unitl it does once re installed up n down


f) And as to specifics of the start timing ring, if you have the mag off and you're looking at the ring, is west advanced or retarded, relative to run timing (or relative to rotation, run timing aside)?

Looking into rear of mag at stop plate and drive cup etc left west increases lag angle,,,,,right east decreases it THAT DONT CHANGE RUN TIMING WHATSOEVER REMEMBER


FINAL NOTE Look yall, if you know how it works you can set the lag angle WITHOUT REMEMBERING ANY OF THIS OR EVEN IF THE 6274 IS SAME OR DIFFERENT, so it dont really matter all that 3 versus 12 1/2 stuff,,,,and thats as follows;

1) You obviously need the lag angle to match the run time advance, cuz if she runs at 25 BTDC but she needs to start at TDC THEN YOU NEED A 25 LAG ANGLE DUHHHHHHHHHHHHHHH

2) When all was new with no wear a 25 advance cup would make her fire at 25 WHEN THE MAG WAS STRAIGHT UP N DOWN IN GOVENOR in the middle of that 10 degress adjustemnt open window slot...

SOOOOOOOOOO once you adjust run timing with a timing light mark the mags location on the govenor flange like Duane did THEN REMOVE N ADJUST THE STOP PLATE so when shes reinstalled she snaps/impulses right at TDC

ANDDDDDDDDDDDDDD if you donT know if its a 25 or 30 or 35 or 6274 drive cup IT DONT MATTER ALL THAT MUCH or if my 6274 info is right or wrong,,,,,if you simply adjust the rear stop plate to where when the mag is installed STRAIGHT UP N DOWN she snaps at TDC then youre close BY DEFINITION cuz absent excess wear (driver and cup and points block n bearings) cuz then the run time advance is close (run time depends mostly on drive cup PLUS mags adjustenmt in govenor) as its in the middle of its adjustment window.


Long time ago Richard asked me to write Wico Mag articles for Green Magazine I just gotta get at it if he still needs them. I can spend 30 mins in my seminars on Mag timing but its hard to cover it here in a few paragraphs with no props or mags or a big drawing board lol, sorry

PS I got much of this info years ago from my own experience and work plus Duane and a ton from mag repair man Glen Schueller down in Texas> he provided me with much of the 6274 (how its different then other cups as far as its top = only 3 versus 12 1/2 for all others) information and Duane and I discussed it only a few months back and he agreed but was going to research it FOR CERTAIN as was his style BUT then he up n passed away grrrrrrrrrr Still miss my friend. STILLLLLLLLLLL it dont matter that much as you can stil set the lag angle so she snaps at TDC when mag is straight up n down in govenor which is middle of that 10 adjustemt slot window

John T
John Ts Wico Timing 101

 

[John T]

Hey there Erik, its high time we got that old girl up n runnin, there appears to be some MIS INFORMATION below so Im gonna try n get the record set straight (to best of my current knowledge, see PS below) once n for all, here goes.

1) For a review and definitions take a re read of my previous Wico Timing 101 post.

http://www.ytmag.com/cgi-bin/viewit.cgi?bd=rrtips&th=18619


2) Now lets take your questions one at a time;

a) My Wico X has the 6274 cup, which is also stamped "25 degrees." Duane's article on mag timing states that the markings on the inner timing ring are worth 5 degrees apiece.

TRUE (marks = 5 degrees BUTTTTTT see below)

b) Mine is set for two major divisions west of due north, a.k.a.

THAT SETTING IS WRONG AS RAIN for a lag angle of 25 which is what you need !!!! Sure, those marks are 5 degrees each as Duane said

BUTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT

For drive cups OTHER THEN 6274, straight up = 12/12 of Lag Angle (so 2 1/2 to West left of up = 25 lag angle) HOWEVER on the 6274 cup straight up only = 3 of Lag Angle

THAT 6274 CUP NEEDS SET ABOUT 4 1/4 (21 1/4 + 3 = just shy of 25) to West left of straight up for a lag angle of near 25 degrees


c) I do not know where the run timing was set before I changed it.

Changing the Lag Angle there in the rear by loosening n rotating the stop plate DOES NOT CHANGE OR AFFECT THE RUN TIMING it ONLY changes the start/impulse timing. Rotation of the mag in the govenor flange changes BOTH start and run timing

d) Is due north on the inside timing ring of the mag 0 degrees, TDC, subject to run timing advances?

Due North straight up = 12 1/2 lag angle for all cups OTHER THEN 6274 cup, in which straight up North = 3 lag angle

e) So in other words, if I want start timing at 0 degrees, TDC, do I need to set the start timing ring at -25 degrees to compensate for my run timing adjustments already made?

If you want start/impulse timing at TDC, (which is correct) your initial adjustment consists of setting the lag angle at 25 if you use a 25 advance 6274 drive cup WHICH MEANS 4 1/2 to left West of straght up for a 6274 drive cup. Then install mag straight up n down in govenor flange n see if she snaps at TDC, if NOT you gotta EITHER rotate mag in flange to adjust ORRRRRR remove mag n adjust stop plate unitl it does once re installed up n down


f) And as to specifics of the start timing ring, if you have the mag off and you're looking at the ring, is west advanced or retarded, relative to run timing (or relative to rotation, run timing aside)?

Looking into rear of mag at stop plate and drive cup etc left west increases lag angle,,,,,right east decreases it THAT DONT CHANGE RUN TIMING WHATSOEVER REMEMBER


FINAL NOTE Look yall, if you know how it works you can set the lag angle WITHOUT REMEMBERING ANY OF THIS OR EVEN IF THE 6274 IS SAME OR DIFFERENT, so it dont really matter all that 3 versus 12 1/2 stuff,,,,and thats as follows;

1) You obviously need the lag angle to match the run time advance, cuz if she runs at 25 BTDC but she needs to start at TDC THEN YOU NEED A 25 LAG ANGLE DUHHHHHHHHHHHHHHH

2) When all was new with no wear a 25 advance cup would make her fire at 25 WHEN THE MAG WAS STRAIGHT UP N DOWN IN GOVENOR in the middle of that 10 degress adjustemnt open window slot...

SOOOOOOOOOO once you adjust run timing with a timing light mark the mags location on the govenor flange like Duane did THEN REMOVE N ADJUST THE STOP PLATE so when shes reinstalled she snaps/impulses right at TDC

ANDDDDDDDDDDDDDD if you donT know if its a 25 or 30 or 35 or 6274 drive cup IT DONT MATTER ALL THAT MUCH or if my 6274 info is right or wrong,,,,,if you simply adjust the rear stop plate to where when the mag is installed STRAIGHT UP N DOWN she snaps at TDC then youre close BY DEFINITION cuz absent excess wear (driver and cup and points block n bearings) cuz then the run time advance is close (run time depends mostly on drive cup PLUS mags adjustenmt in govenor) as its in the middle of its adjustment window.


Long time ago Richard asked me to write Wico Mag articles for Green Magazine I just gotta get at it if he still needs them. I can spend 30 mins in my seminars on Mag timing but its hard to cover it here in a few paragraphs with no props or mags or a big drawing board lol, sorry

PS I got much of this info years ago from my own experience and work plus Duane and a ton from mag repair man Glen Schueller down in Texas> he provided me with much of the 6274 (how its different then other cups as far as its top = only 3 versus 12 1/2 for all others) information and Duane and I discussed it only a few months back and he agreed but was going to research it FOR CERTAIN as was his style BUT then he up n passed away grrrrrrrrrr Still miss my friend. STILLLLLLLLLLL it dont matter that much as you can stil set the lag angle so she snaps at TDC when mag is straight up n down in govenor which is middle of that 10 adjustemt slot window

John T
John Ts Wico Timing 101

 

[Erik B]

Thanks for taking the time to provide all that detail. To make sure this has sunk into my head correctly, I"m going to restate what was already said, and please tell me if I am backwards.

My mag"s lag plate was set at 4 clicks CW of center when I pulled it, after it wasn"t starting well, after setting run timing to 25 BTDC with a light. What it should have been was 4.5 notches CCW of center. So in other words, where mine had all but 3 small divisions remaining to the left of the center pointer, when viewing it removed, from the back, it should have been exactly the opposite, all but three small divisions remaining to the right of the pointer.

Put another way, in your summary of where to move the lag plate even if you don"t know which one you have, it sounds like you use it to undo the angle of the mag. has been turned for run timing purposes, kind of like imagining the lag plate is on a pendulum and you always want to keep the bottom center marking pointing toward the center of the planet. That"s hard to visualize from a forum posting, but helped me to understand how to have a reality check when all the adjusting"s done.

 

[John T]

Sounds like youre gettin the concept correct and once thats the case YOU DONT NEED TO REMEMBER ANYTHING MYSELF OR ANYONE TOLD YOU.....and whether a 6274 cup is same or different (as I believe) then any other 25 or 30 or 35 cups.

The mark on the stop plate needs to be around 4 + HASH MARKS TO THE LEFT CCW WEST OF THE TOP CENTER NORTH INDEX MARK for a 25 degree lag angle when using a 6274 drive cup....... Left/Right and East West are while looking in at the BACK of the mag i.e. West is left CCW when mags removed n youre lookin at the drive cup

BUT YOURE ALSO RIGHT when you move it youre simply backwards compromising to set the start/impulse BEHIND (i.e. lags) wherever you set the run time advance. YOU SURE DONT WANNA HAVE TO LOOSEN N MOVE THE MAG FOR STARTING THEN RE ADJUST FOR RUNNING so thats why you adjust the lag angle so its x degrees less then where shes running and so she starts at TDC......

Nuff said,,,,,,,,,

John T

 

[Anonymous-0]

Duane & I once had a discussion on installing & timing magnetos. Duane advocated installing the mag for a TDC trip (standard proceedure) then the drawing of a line on the magneto flange across the gasket and over onto the governor. We found we did almost exactly the same thing. I had one other little "twist" that I find makes it still easier and requires a bit less trial and error!

Before I put the mag on the tractor, I pencil mark where the stop is on the mag's mounting flange. Doesn't matter if you mark the center of the stop's vee, the leading edge or the trailing edge of it, just mark where it is some how and in some place that will still be visible after the mag is on the tractor.

I then install the mag carefully setting it for a TDC impulse trip. At this point, I transfer the mark on the mag over to the governor case. Now just like Duane suggested, I have a single line showing how the mag is positioned with the governor at the TDC impulse trip point.

Next I measure and mark the flywheel with the run timing I want and I start the tractor.

Next using a timing light I move the mag to establish the desired run timing and shut it down.

Now I transfer the governor mark over to the mag flange now that the mag has been moved. I now know where it was, and where it needs to be and how far to move the stop ring.

Next I remove the mag and simply move the stop to the OTHER (the second) mark on the mag flange and erase the first mark from the mag.

If you put the mag back on lining up the mark on the mag and the mark on the governor you'll have BOTH a TDC start (I always check that trip point to make sure) and the run timing you established with the timing light.

By marking the stop's location FIRST this method tells me "how much to move the ring" to re-establish the TDC trip after I've moved the mag from the original setting to the needed run timing adjustment. Rarely takes a second run through. Works even if one or all the internal marks have been obliterated!

 

[F-I-T]

That's how I do it Al. You can get it so close that way I doubt that I have had to go around a second time.

 

[charles lendman]

Now who said there isn"t a "tractor God"?? What a great bunch of helpful people here!! Love to read ALL the info!! Politics noitwithstanding!!LOL....Charles

 

[Erik B]

And now to muddy the waters with an observation from experimenting today:

The B starts way easier when the start timing is set to about 10 degrees BTDC, not at TDC, where it"s supposed to be.

Run timing is still at 25 degrees BTDC, and the mag and flywheel have recently been removed and carefully put in their correct orientations.

 

[Anonymous-0]

Amen.