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Up Topic Welding Industry / General Welding Discussion / need clarification on sa200 trouble shooting
- - By mooseye (**) Date 03-23-2008 01:16
This old girl has been in the yard in the weather for 10+ years due to a leaking head gasket. The new gasket has hung on the back porch for the same time period. (I have been known to put things off)  Well, I got the itch. I drug her out and installed the new gasket, new plugs, cleaned the carb, honed the points and got the engine running like a top.
The problem is, no arc.
I saw the posts on checking the exciter brushes and slip ring and they look good. I tried to flash the exciter, but I don't know if I did it correctly. I didn't get any sign of an arc or indication that there was current flowing from the battery to the brush holders. I also saw the post on checking the shunts. I have steady 39.4 omhs across the blue and brown wires. I do not have voltage at the 110v dc outlet either. There is not even a small arc at the lead studs at high or low idle, The rehostat  and main switch are clean and have continuity to the studs. I have not, as yet, removed the wrapper since the screws were very rusted. I sprayed them with penatrant to set till probably Monday.
Are there other tests I can do other than visual?
The machine was welding fine 10 years ago. lol
Parent - - By mooseye (**) Date 03-24-2008 00:30
Well, I couldn't wait till tomorrow, and the penetrant had done its job. I went ahead and pulled the wrapper off and it was a mess with spider webs and straw and dirt as well as a few rat droppings.
I did not see and broken/chewed wires, but the commutator looked like coal. I will give it a rub down tomorrow since there is a church right behind where the machine is and I didn't want to disturb the congregation.

http://i198.photobucket.com/albums/aa112/mooseye/DSCF0001-2.jpg

http://i198.photobucket.com/albums/aa112/mooseye/DSCF0010-1.jpg
Parent - By chris2698 (****) Date 03-24-2008 01:07 Edited 03-24-2008 01:10
that looked like mine when I tore it apart full of spider webs and dirt mine welded great but the motor was shot and is now at the machine shop getting rebuilt
Parent - By KSellon (****) Date 03-27-2008 16:20
Vacuum out the housing, as blowing it out with air will only cram debris further into the housing.

The bevel on the brushes needs to meet the contour of the armature. So when you reinstall brushes check the bevel, you may need to seat them using FINE FINE grit sandpaper. (cloth side to armature and grit side to brush, work back and forth until bevel matches). You will know if its right because you won't see arc from the armature to the brush (only a SLIGHT sparkle).

If you don't have 110, you will not have weld output. The 110 comes from the exciter coils and armature. This voltage is the sent to the generator housing coils as a 'flashing current'. Once all that happens it travels thru you rheostat (control) and output stud.

I always tell everyone, the first thing you HAVE to do before starting one that has been sitting for even 6 months, is remove the wrapper (main brush cover), remove the rats nests clean it out, check your brushes and then fire her up.
Parent - - By mooseye (**) Date 03-24-2008 16:28
Ok, I cleaned  the main comutator and got fire from the leads then I noticed sparking from the brushes. Some of them seem to be stuck.
How can I free these up withou dissambling them?    I don't really want to start messing with those rusty scresws and bolts that they are mounted with. I have tugged gently on the pigtails of the brushes. Some of them will move, but not all.
Is there any trick to getting them free or will I have to remove the mounting hardware?
Parent - - By mooseye (**) Date 03-24-2008 18:05
Well, never mind about the brushes. I got them loose. I took the entire brushholder off after breaking the first bolt I tried to take out. A little drill work and retap. So I didn't try that again. I took the one bolt out of the end of the brushholder mount and every one of them was stuck. They would not even move with the holder off. Freed up now and I am going for some contact cleaner.
I guess I am on my own on this one. But thanks anyway.
Parent - By chris2698 (****) Date 03-25-2008 02:14
Ksellon knows a ton hopefully she will give you some tips or you could pm her
Parent - - By KSellon (****) Date 03-27-2008 16:12
How the heck did I miss this post? Call me if you still need help. I am sorry for missing the post. I have been watching the SA-200 board (further down).
Parent - - By mooseye (**) Date 03-28-2008 15:47
As you can see from above, I got her burning "stick" after a good cleaning and freeing up the brushes  My idler was acting up, so I dissembled it and the solenoid plunger was sticking down. I had the old idler that came on the machine, so I swapped the sol. and was in the process of testing and adjusting when the engine began dying. It would restart and run a few minutes then die again. It did this quite a few times till it just would not restart. Now it has no fire to plugs at all. I held my finger on the coil tab while cranking and it was enough to make me remove it quickly (lol) but it didn't feel like a hammer like it should. The points look great(flat mirror finish), the condenser bench tests ok several times and the plugs are less than a week old. I did try with a known good plug also. I am now leaning toward the coil as the problem component. I can get a  MRD4/2 360 A310 mag if the coils are the same, which I believe they are.
What do you think?

PS   I will never let any machine set that long again. This unit is one problem after another and then some.
Parent - - By KSellon (****) Date 03-28-2008 17:39
I am not familiar with the mag you are speaking of. But as long as its a 15 degree mag you should be ok.
Parent - By mooseye (**) Date 03-28-2008 18:05
It is a 360 degree magneto, hence the 360 in the designation number.  I don't know what exactly that means though. Also, the 4/2 means it can be used for a 4 or 2 cylinder engine. It was being used on a 2 cyl. Wisconsin engine so 2 of the plug wire holes in the cap are sealed with something.
I looked at a parts list and both mags seem to have the same coil part number so it should work. I can get the whole magneto for half the price of a new coil alone. The only thing is, I don't know how or have the capability to test my current coil. I hate parts swapping but sometimes that is the only alternative for a shade tree mechanic. I don't have the funds or the need of the machine right now to upgrade the distributor. I would like to get it in usable condition in case someone needs it more than I do. $$$
Up Topic Welding Industry / General Welding Discussion / need clarification on sa200 trouble shooting

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