[shortlid]

I have been looking for a Gravely walk behind tractor for years. Finally found one in my price range. Can you folks help me get it back up and running? I belive it is a 1958 but build plate ois missing. Engine is free, I have changed plug, changed oil. Tank is rusty, but no holes.

 

[jrd]

From those pix, it looks decent. Reasonably clean, not obviously abused. The MA106 is a good unit, once you get her running you'll have many hours of fun brush hogging.

My '58 has a round-end tank, yours is the more common flanged-end. You've also got the newer style shroud. Either your machine has had some parts replaced (very common) or it's newer than '58, maybe 63 or so.

I PMed you; the basics of getting these beasts running are pretty much the basics for any simple engine. Compression, spark, mixture, and it pretty much has to run.

You should also check out the gravely manuals site. Lots of good information there.

 

[shortlid]

Thanks for the reply jrd. Here are pics from side of Magneto. Is this the shut off? Nothing on handle bars.

 

[Antarctica]

Yes - you hold that button down, shorting the mag, until it dies.

Getting it going:

1) verify spark
2) If spark is there, try to get it to cough with some starting fluid.
3) report back results.

 

[jrd]

What Antarctica said.

These engines are so simple, if the basics are there, it pretty much has to run.

Per PM: Pull the plug, reconnect it to the wire, lay it on the head.

Turn it over by hand. You should hear a snap from the mag at TDC (verify by looking through the plug hole at the position of the piston). When it snaps you should see a spark.

If you don't, it's time to pull the mag and investigate. Most likely points and/or condenser. When you pull the mag, take note of the timing marks, so you can put it back together the same way.

 

[edwardgoodridge]

If you plan on using it a lot my opinion is get the magneto professionally rebuilt as intermittent starting and stopping problems are often caused by those wico magnetos. The more they wear out the later they fire which is why checking magneto to engine timing is important. If you find slow engine speeds fail to give expected torque better consider getting compression back up that also makes the tractor safer to use.

 

[nhgravely]

If you set the engine to the marks on the mag (the mag drive has a line on one of the ears and the fixed shield on the mag has a line) and you don't move the engine at all, you can take the mag completely off the tractor and work on it @ the bench. Just don't rotate the engine with the mag off. After you get it fixed (the mag) then bolt it back on exactly as your removed it.

I have found that the points are almost always dirty or oxidized and won't make contact. Also, the impulse coupling on the drive end can be sticky and cause the impulse not to set. You will never be able to hand pull one of these over fast enough to start it without the impulse. You can bench test the mag by anchoring it down to a metal table and laying a connected spark plug on or touching the aluminum body and spinning the drive using a vice grip as a handle. Do not fire the mag without grounding the spark plug wire or attaching it to a grounded spark plug. Bad for the coil. Really very simple to work on if you take your time and read the manual.

 

[edwardgoodridge]

A metal screw driver between the magneto body and kill button also grounds it. Don't forget to take it out when making a starting attempt.

 

[fireant911]

... You will never be able to hand pull one of these over fast enough to start it without the impulse...

Hmmm... that may be the case of WICO magnetos but I have a Fairbanks & Morse magneto that I operated at least 150 hours of run time without that magneto snapping EVER. In fact, with the magneto off, I can freely hand spin the shaft with no resistance yet it continued to run and hand-crank for a year and a half (cranking with normally two pulls). I set the timing when the unit did snap but once that stopped, the unit hand-cranked just like it always had with no further adjustment. Later, I removed this non-snapping magneto to inspect further and reset the timing by aligning the marks and it cranked just as before.

I did seek out a replacement magneto (WICO) and the old non-snapping Fairbanks & Morse has been sitting on my workbench untouched. I know that others have said these units cannot crank without the snap of the magneto but I have an example of one F&M that operates fine without the impulse. I have read here before on numerous occasions that these cannot operate without snapping AND I am NOT trying to argue but I do not totally agree that the machines cannot start without a snapping magneto... at least that is not the case with my Fairbanks & Morse. No arguments from me... just saying that my experience has been different!

 

[shortlid]

I took Wico mag off cleaned points with very light sandpaper, wire brushed off bottom of mag, mount and where it mounts to tractor. Get gREAT spark first snap of mag, then nothing.

 

[Bodjick L]

I've had to take my magneto off and clean the surfaces to ensure good contact with the engine mounting surface. You might also want to check the condenser.