Two bolts and it’s off.

 

Do you put location marks on the mag to reinstall? Will the timing be affected?

 

I would suggest yes to first and maybe to second. Have you ever pulled tire for better access.

 

I am not familiar with Gravely but on other engines with the external mag such as Wisconsin there is a pipe plug in the casting behind the mounting face. Remove the plug to see the drive gear then with the spark plug out rotate the flywheel until you see a tooth with a bevel cut out. Now remove the mag and do not disturb the flywheel until the unit is reinstalled.

 

I'll have to look to see if it has a pipe plug. I've pulled the distribotors out of Harley's. They have a timing hole to align the timing marks. This thing is really difficult to install the points with the mag in place. I've done it but it is a pain in the butt.

 

If this is a strap start model do not experiment with spark advancement. You might cause yourself a kick back. Put a drop of machine oil no more on the pad inside.

 

The marks are on the face of the mag but you should only use those as a guide to get you close. jrd's instructions are pretty fool proof...just don't crank the engine while you work on the mag and you should get it back together just fine.

 

Right.

Check out the condensed service manuals (you've already downloaded those and looked through them, right? ) There's a good drawing of what the face of the mag looks like, including the timing marks.

 

Yes, I have several manuals downloaded and have viewed them. Just was not sure what I was looking in the drawing as the Gravely is not located here where I live. I'll look at this we we get back up to the cabin.

 

I assume this is a strap start L and this is a well used wico magneto. It tends to fire a little past tdc as it wears out. Which is a safe place to leave it. If not happy with that then consider do the engine timing which is not difficult but its dangerous if you should by mistake advance the timing too far. Good luck with your project.

 

Why don't you consider this. Pull the spark plug and ground the magneto. By putting a small screw driver behind the stop button. Turn the strap pulley clockwise by hand to take out the slack. Continue on slowly until magneto impulse arm clicks. Hold camshaft right where it is with locking pliers. Now go ahead and make your own marks. The chain probably should come off if this is electric start. I'd do almost anything to avoid pulling magneto. Just to clean the points. Good luck with your project.

 

As a gravely wico magneto wears out it will no longer fire as originally set. It tends to fire later. So you can't use those magneto markings. At least not as a way to get it to fire exactly at tdc compression. Face book gravely club has this under discussion right now. You are well advised to read it.

 

The point of my earlier post was not "How do you get the timing right". It was "how do you get the timing back where it was, if you pull the mag off".

It's correct that when setting timing, you're better off working out where the mag actually fires, than simply trusting the marks.

I disagree about pulling the mag. I can do a much better job by getting the unit up on a bench where I can see it, than trying to do it on the machine. There are often multiple right ways to do a job.

 

Several years ago I went thru the same problem when starting the engine. At that time I removed the points and cleaned them. What a pain in the butt with the mag installed but it did fix my problem. This machine does not get ran that often & I started having problems again. I did remove the top half of the points and cleaned it but tried to clean the bottom half while the mag was still installed. I found that hard to do & that is why I posted the question. Although what I did, did help considerablly, I am going to remove the mag and see how that goes. It has to be easier than trying to work on the points while the mag is installed.

 

I admit that I haven't removed one for a long time, but I've heard that it's a ideal time to clean the bottom and the base to ensure a good ground

 

What I did finally with a old wico magneto that gave me endless problems was send it out for a professional rebuild. Then I replaced high tension wire, plug and all the misc parts that go with it. I have basically a new system. I am now hoping that long term storage will no longer give me a problem.

 

If you don't run these old machines too often, which mine does not run for quite some time, what causes the corrosion on the points? Also how would the rebuild you speak of eliminate this problem?

 

Different Ls have different Magnetos and also different mounting holes. It all depends on when built and if the Mag was replaced. You can have either two or four mounting holes in the chassis for where they mount. So then you also have some that use two bolts and some that use one bolt and one stud. Two bolt units normally have lengthwise pattern while one bolt/one stud ones have them crosswise. If someone lost the stud and installed a bolt, those are a royal pain.

 

My rebuild cost around $150 including core exchange its a investment I was glad to make.