620 starter question

John, you say,,

Quote:--“ It would only turn over slowly wahoo wahoo wahoo sound. No fire. Tried again the same”

--That is usually a sign of thick motor oil at the ambient temperature you were starting it at.. Even a good multi-weight will drag the starter speed down at –8°F.. Once the engine drags the starter down the current draw goes way up & that means very low voltage to the ignition coil so you get a “no start” along with the slow cranking.. That coil needs all it can get even with a by-pass starting system so low cranking speed pulls the coil below it’s spark producing threshold.

Quote:--“ (tried it) Again and it turned it over really fast (like it should) and it started right up”

--That is usually a sign of the engine firing just as soon as the starter starts cranking so the consecutive firing of the cylinders helps the starter to crank easier. Once they fire off just once & the starter speed increases there is plenty of spark to start it with.

Quote;--“ It died when I failed to manipulate the choke fast enough because of my big mittens. Tried to start it again and it turned over slowly again”..

--With the start & stall you probably didn’t fire on the first turn of the starter again so were back to the slow cranking again & therefore no spark to fire up with..

Judging on your slow/fast cranking & the –8°F ambient I would wait before judging the starter worn or defective..

A slow initial cranking could be normal at 8° below zero if your engine oil is thick, or your battery is slightly undersized for your tractor..

You might see how it acts at 30 & if ok then suspect a slightly small battery or thick engine oil..

You could also have a broken ignition by-pass wire between your starter & ignition resistor.

Clooney

The time it did start, it not only turned over much faster, but the starter had a little different sound. I will check all other alternatives before tearing into the starter. I would guess that the starter hasn't seen the light of day since 1957.

You might also check the starter to casting bolts behind the flywheel as those have been known to work loose & cause starting problems also.

Clooney

What is the purpose of the other wire connected to the switch? It was connected on the side of the switch and there was a bunch of rust all over that connection. I cleaned it up as well. I may put it back in and see how it works before I do anything else.

The throw-out mechanism is quite sticky. What type of oil should I use to lube it? Should probably be something fairly thin.

Thanks again.

You ask,,,
Quote:--“ What is the purpose of the other wire connected to the switch? It was connected on the side of the switch and there was a bunch of rust all over that connection. I cleaned it up as well. I may put it back in and see how it works before I do anything else.”

--That is the starting By-Pass wire I referred to in the first post. The purpose of that wire is to by-pass the ignition resistor & run full battery voltage from the starter battery cable to the coil side of the ballast resistor.. It’s purpose is to raise the coil’s voltage to full battery during cranking only.. If that is/was corroded it could lower the coil’s cranking voltage & cause a no-start if/when the starter works hard & lowers system battery voltage.

Quote:--“ The throw-out mechanism is quite sticky. What type of oil should I use to lube it? Should probably be something fairly thin.”

--I used to use a good light weight motor oil but lately use a synthetic motor oil.. Any good motor oil should work.

If you have a good ignition system that gets enough voltage during cranking that tractor should start even if it cranks slowly.

Clooney

1) Remove, clean and wire brush, and reattach EACH N EVERY Battery and Starter and Ground cable connection. I use the felt washers under the battery terminal connections then spray them with that red anti corrosive spray.

2) You might wanna have that battery load tested at a battery shop just to be safe.

3) If she still acts the same despite all the above, it could be a faulty carboned up or burned starter switch ORRRRR RR a burned, pitted or worn down exterior starter motor post, as thats what the switch engages against. It would be necessary to remove the swith and inspect both it and the post under it for carbon or pitting. I have had some success on the post by cleaning and light filing and wire brushing to get it back down smooth n clean. Similarly, if the switch contact is badly burned or pitted or carboned up, it may need replaced. NOTE if it has the extra lil side terminal post get a similar switch cuz a wire from that post leads up to the coil or ballast used as the ballast by pass starting system.

4) Finally, if the battery,,,,, ,,cables n connections,,,,, ,,starter switch,,,,, ,,,and exterior starter post are ALLLLL LLLLL good,,,,, ,then it may need starter repair. That may be simply new brushes as you asked, but it could also have worn bushings/bearings or even a short in the armature. Often a simple clean up and a set of new brushes and re lube will get them going. However, I always clean or replace that exterior post and install a brand new switch if Im in there. NOTE: Remove a battery cable if youre down at the starter to avoid a major short when working.

Good Luck n God Bless, let us know what happens.

John T in Indiana

John T