jd g timing

Im having trouble timing my 47 john deere g with a wico mag.If i pull the mag clear out,should there be a mark on the gears inside where it should line back up?Also im assuming the left hand cyl as yoou sit on the tractor is #1 cyl.I dont have a manual for it but i do have one for a 60,are they simmilar?THANKS,TIM

If you pull it all the way out, all you see is the open female drive slot in the end of govenor shaft where the mags drive coupler mates into.

The advance run timing is a function of the mags drive cup (like if its a 25 or 35 advance drive cup),,,,,,,,,the rotational position of the mag in the governor housing (forward CW retards, CCW backwards advances) ,,,,,,,,the points gap,,,,,,,,wear n tear n slop in the drive n gears etc.,,,,,,,,,the correct govenor to cam timing

You can use a timing light when shes running to see just where the run time advance is firing it (should be in the 20 to 30 BTDC or so range) and that can be adjusted to some extent by loosening the mags top n bottom bolts n turn it CW to retard or CCW to advance it.

The initial start impulse timing (when she snaps) is a function of the mags rear lag angle adjustment plus again the CW or CCW rotation in the govenor and points and wear etc. That needs to be right near TDC for good starting.

If CW or CCW rotation in the govenor cant get the run time advance in the 20 to 35 BTDC range you either need a different drive cup or perhaps the govenor to cam gear timing is off.

Duane Larson has a canned timing procedure on these, Ive never refined and saved mine, I need to do that.

John T

take the mag turn it all the way to the left and turn the flywheel until the holes in it are level with the ground. turn the mag tio the right until it trips and tighten it down. if it back fires your 180 out. you can either redo it or just change places with the wires in the mag.

Yo John, Dont you really mean turn it TO THE RIGHT (Forward CW) ,,,,,,,then get the flywheel where you told him (TDC on left cylinder) then slowlyyyyyyy turn it backwards TO THE LEFT (CCW) until it snaps?????????

Of course THAT ONLY SETS THE STATIC START IMPULSE TIMING, NOT THE RUN TIME ADVANCE. It takes a timing light to tell where shes actually firing at when shes running. The timing light can also then be used to adjust the run timing by loosening the mag and rotating it (forward CW to retard and backwards CCW to advance) HOWEVER one has to then mark the exact position (to preserve the run timing) and remove the mag to adjust the rear stop plate to re adjust the start impulse (like Duane Larson suggests) as rotation of the mag affects BOTH start n run timing.

I do it a lil different then Duane, I set the correct lag angle,,,,,,,then by mag rotation get the start impulse at TDC,,,,, then fire it up n stick a timing light on it and if its in the 20 to 30 BTDC range I just let it go. If I were going to pull it or wanted to insure absolute max HP then I would go the extra step n do as he does if I dint luck out on the first try


Yall take care now

John T

thanks for getting my left and right correct. i've never timed mine but once and that was in 1999 and it cranks and runs good as i described. i'm not into all this techinical stuff, but probably should be. i just try to keep it simple so any other dumb bunnies like me can get it close and can play with a little bit from there. i'm glad guys like you know all the ins and outs of all these things. i'm just to dumb to follow them so i have to go with what i've been told and seen that it works for me.

Hey John, sounds like you have yours a poppin just fine DONT FIX IT IF IT AINT BROKE LOL.

Reminds me of when my daughter was young learning left from right n we were always preaching at her NO ITS YOURE OTHER LEFT LOL

Happy Easter

John T

Thanks for the info,i got it running and know i need to time it,where is the timing mark? And what should it be timed at?Thanks,Tim