Gravely magneto question

pete3046 · Dec 9, 2015

Hi,
I have a new to me Gravely L and want to give it a major tune-up, clean carb / fuel system, oil/filter and service the magneto. I plan to change the points/condenser and clean the impulse, etc. I'd like to take the magneto of the tractor for this and have a question on the timing. If I line-up the coupling timing mark to the magneto mark prior to removing and then reinstall with the same match, will the timing be correct? Also, any other magneto tips are appreciate!

Thanks,
Pete

Bret4207 · Dec 9, 2015

It should be.

El Toro · Dec 10, 2015

I used a dab of finger nail polish then don't turn the engine until the mag is reinstalled. Hal

Bret4207 · Dec 11, 2015

If you lose time you reset it by lining up the mags timing marks and setting them when the piston is 3/8" before TDC.

ztrmower · Dec 11, 2015

if you put back exactly as you take apart nothing should change.

pete3046 · Dec 11, 2015

Thanks guys! I'm working on the Gravely this weekend! I have the mag off and the carb soaking and parts should be here tomorrow!
Pete

pete3046 · Dec 11, 2015

Thanks guys! I'm working on the Gravely this weekend! I have the mag off and the carb soaking and parts should be here tomorrow!
Pete

jeffcat · Dec 12, 2015

I was going to tell ya if the Mag works then leave it alone! There are four types of mags on model "L" machines with Fairbanks Morse and Wico the most common. Really old ones were Edison and Bendix. Don't break that cover on a FB cause they cost over $75.oo if you can find them. If you didn't loosen the drive collar coming out of the front of the engine then timing it up is easy. Take out the spark plug and hand turn over the engine really slowly. The piston should be just before the top of stroke when you hear the mag go SNAP and you should see a white hot spark. If not, loosen the two bolts that hold the mag and turn the drive backwards one halt turn. That should put it back in tune.. DON'T loosen the drive collar unless you want to have a massive pain in the butt getting it back on mark. ALSO you want to the mag, adaptor collar, and drive to be as straight as possible so things don't bind or wobble. Have fun

Bret4207 · Dec 12, 2015

Edison-Splitdorf. Good mags.

When you put it back together and bolt the mag back down, make sure you leave a bit of clearance so the coupler isn't real tight between the in mag and impulse drive. 10 thou or so should be plenty. I busted one of those couplers one real cold morning because I set things with no gap.

pete3046 · Dec 14, 2015

I have Wico mag. I did take it off, cleaned it up, new points, condenser, checked the 'mag' timing on the bench and then reinstalled with turning the motor. In general the mag was in good shape. at the same time, I drained fuel, cleaned/rebuilt the carb and fresh spark plug. She ran much better after her little tune-up. There is still a slight miss at idle now and then, but overall Much better.

Although the one item that still doesn't work is the kill switch on the side of the mag. I choke the tractor off and I'd rather not do that?

Thanks,
Pete

Bret4207 · Dec 14, 2015

You just need to fix whatever isn't allowing the switch to ground. Could be a broken wire, which might explain the miss at idle.

pete3046 · Dec 19, 2015

so, I got a new little kill switch kit and pulled the magneto off again and I noticed the new kit has this little metal item that looks something like a little flag, spade opening on one end and round terminal end on the other end. The old kill switch did not have this part and although I think the 'flag' is shown in the parts breakdown, it's not clear to me were it goes and what it does? Any help would be appreciated!

Thanks,
Pete

Gravely magneto question

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