F 4 timing.......

banjoman09

Well-known Member
I took the cap off the back of mag- turned brass strip up to no 1 on cap- put back on and when I try to put it on coupler on
tractor the "tabs" are half off ? And I have the no 1 cyl on TDC....whats wrong?
 
Do you have that coupling with all the holes & 2 little bolts ? You have to adjust that to get it to trip on TDC.
 
The rotor is timed to the magnet shaft with marks There should be no need to simply rotate the whole thing, it must fit the drive coupling slot. jim
 
TDC on the flywheel is the same as piston up. Neither assure that your engine is on the compression stroke. 50:50 chance. They line up at TDC on exhaust as well!! Jim
 
do you have the impulse disengaged ? If this was a runner before I wouldn't go moving the mag coupler just yet , take the valve cover off so you can watch the valves , make sure you see the intake valve open and close then when you get to TDC you put your mag with the impulse disengaged so you can turn it should be lined up with no 1 cylinder and with the mag fully retarded the points should just start to open AFTER the TDC mark has been passed on the flywheel. If the crank and cam are in time and you haven't had the governor out it should line up without having to change the coupler position, but if it has been apart, all bets are off and you will have to find the closest set of holes to make the mag line up, just remember the points must not open until a couple of degrees AFTER TDC , otherwise the spark will happen too soon and it will kick back while you are cranking and I am pretty sure you won't find anyone who finds that outcome pleasurable. The service manuals are easy to find for the F-series and have a pretty detailed section on setting mag timing.
 
time F-4 Mag - I felt compression when piston came up- It was 180 off but I am right now; so how does the mag go in? It can be 180 off also ?
a175707.jpg
 
you need to have the impulse disengaged or else trip it and back it up , because there is about 90 degrees or so where you are just pushing against the spring before it snaps and turns.
 
What / and where - is the "auto impulse coupling" ? Im sure my motor is "set" where it is supposed to be- so how do I time the mag to the motor? Take off the back cap? There is a strip inside that looks like a "rotor strip? built in the wheel; should it point towards no.1 wire on cap? ??? ??? If so- then the "cogs" dont line up on the coupler. Im trying.......
 
That coupler on the tractor should have 2 bolts in it. Remove them & turn to line up with the mag. Put the bolts in & turn the engine over making sure it trips at TDC or a little after. If not, fine tune it one way or the other. Looking at the picture again, did you add that piece with the female slot? Take it out again & move the mag closer & see if there are 2 holes that line up to hold it down.
 
Banjo,there is a lot of bad advice here,please don't remove the two bolts,this is for fine tuning.You have your motor sitting on TDC,but your mag is against the impulse,you need to back up your motor to line up your drive.Your mag is against the impulse it will actually travel father before it snaps this is why its not lining up.The proper way of doing it is to use a paper clip through the hole releasing the impulse.Chances are if your tractor was being used prior to you,theres no need to adjust your mag drive.304-582-9995
 
I'm kinda new to the discussion, might have missed what mag was on it prior.
If it had a Fairbanks or Wico mag on it the coupler may be setup for that,
can't remember if i have had to cahnge the setting on the coupler or not in the
past when i did the same change to the F-4.
I think some of the posters are just telling you to go through all the motions
because that is the most sure way to do it, most times i don't trust how a tractor
was timed previously for good reason, sometimes if i end up cahnging the setting
right back to where it was, at LEAST i know its right and never have considered
it a waste of time.
BUT, if i did one today it would be far from my first one.
Patience and time teaches.
 
Okay.....I will call you and visit about all this If I can; maybe tomorrow afternoon ? or will Sunday after lunch work? Thanks for your help - and all of you ...I will get this!
 

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