First issue with Sa250

Date 03-26-2012 00:44

About three weeks ago I had a belt problem. Machine would kick to high idle and belt would chirp. Removed the hood, tensioned the belt and found out that the bearings in the pump were worn. Fan would wiggle a bit. Figured it would last a week. Put machine back together and checked belt chirp. Flipped switch to high idle and no chirp. Turned switch back to Auto and it idled down. Tried one more time, high idle, no chirp back to Auto.....uhhmmm, back to auto?...idle?? Hello?? Idle?? Ran it for three weeks at high idle while I would troubleshoot on Sundays when I got back home. Thanks to John at Stumpf's for the info!!

I tested here, tested there, tested it everywhere!! Found my reed switch broken and while checking one of the wires off the pc board the terminal pulled off of the board. Well, there's some simple troubleshooting!! Ordered new board, new reed switch and wire. Meanwhile I replace upper and lower hoses for radiator, coolant, water pump, plugs, wires, gas cap seal. Installed my Murphy gauges and so on. Today I pulled the hood, doors(really getting annoying) and installed the new reed switch, new board and found one of the electronics burnt on the back side of the board. Thought, hmmm, maybe?? Started it up and it went to high idle......and stayed there. Back to the schematic and checking with the meter. Low and behold after a few minutes I find I have no voltage and my high idle/Auto switch. Chase down the circuit and find it is fed from the back of the alternator thru the oil pressure switch. Voltage on the input side of the oil pressure switch, nothing out the other. Took a jumper wire and jumped the switch. Started and went to idle immediately. Struck and arc, went to high idle then went back down after a few moments.

So, not wanting to burn massive amounts of fuel while I wait for the part and me to get back home this weekend I had to rig up some farmer wiring. Took a toggle switch, one wire to the power side of the oil pressure switch, then the other to the other side. Turn off the switch and it will pull to full fuel while I crank to start then run up to high idle. Then I can turn on my temporary toggle and it will perform as normal! So glad to have low idle back! Bit of a backwoods solution but I can't use my backup welder while I wait to repair this one as I am using both.

Glad it's a nice simpleton welder!! Not some complicated computer controlled thing!!

By texwelder (***)

Date 03-26-2012 03:09

What year is your sa 250 and how many hours you got on it. I have a sa 250 too and mine will idle down some times and sometimes it won't its a 97 model. Just never really messed with it much since its a back up machine now, but now I'm curious

By Cumminsguy71 (*****)

Date 03-27-2012 00:30

Mine is a 1991 model. About 2 weeks ago I had an oil pressure light and it would not idle down. Then this last week oil pressure light went bye bye and it would not idle down. When I would test the voltages at the magnetic solenoid it was erratic from day to day, week to week. Sometimes I'd have it, other times not. Same at the ot Auto/High idle switch. Erratic voltage's 6 volts one day, battery voltage the next.

Got it to where it would idle down, little bit hillbilly but effective and then the starter took a dump today!! Never ending cycle! Got a place I deal with that can do a quick turn around for me so hoping to get off this job and jerk the starter at the jobsite and drop it off on my way back home. Oddly enough tried the welder this a.m. and it would not start. Went to the plumbing supply to pick up some things and went out to start the truck and, click, click!! Worked it a few times and it started. Kinda hope I could get a week to do maintenance on all of my junk!!!

By Oneatatime (**)

Date 03-29-2012 03:22

Might sound dumb, is the oil pressure light bulb burned out now?

By texwelder (***)

Date 03-29-2012 11:37

Yeah the bulb on the oil light might be burned out have seen that happen several times

By Cumminsguy71 (*****)

Date 03-29-2012 18:12

No, light works. Had no voltage at the Auto/high idle switch and it's fed from the oil pressure switch which is fed by the alternator. The oil pressure light is fed voltage from the Auto/high idle switch. So domino affect led me to an open oil pressure switch. My rigging worked good except for the problem of the starter going bad on Monday!! Used it yesterday putting on some service connections and auto idle works fine when my toggle supplies voltage to the Auto/high idle switch.

Had the starter joint rebuild the starter. Said it was the original starter. Pulled the back off and he laughed. Said that I got my use out of the brushes!! The armature was starting to wear into the screws that hold the brushes on!! He turned the armature on the lathe, put in new parts and this thing spins this engine over so fast it seems like its going to fly off the machine!! It's never turned over like this before!!

By texwelder (***)

Date 03-30-2012 12:29

Yeah y sa 250 is a 97 model and everything is original