What NOT to do...Unless you start from BATT switch, and have a starter fire

[daddysgirl]

I feel the need to preface this lengthy albeit important post by stating that I have been working on electrical systems for 15 years. The events described below are a direct result of a mistake I made. I got distracted, and It's worth explaining this because I am well aware of how much worse it could have been.

OK. Here goes:

I have had to rewire the rear junction box, make harnesses for everything in the engine compartment, and at some point, I'll do the dash switches.
I have found and fixed many bad wires, all hoping (really hoping) that the starter was OK. It's a 42MT and the ONLY limit I have on my mechanical ability on this 8V71 is changing parts that are that heavy.

I fully admit to a couple of "stupid, I know better than that" moments no one can afford to have.
For this embarrassing experience, what you need to know: Master switch was OFF. The installer (15+ years ago) wired the neutral safety switch to the starter little side terminal, where the switch wire should go, and to rear stud 12. So, I put it back. I also ran the water hose under the bus to make sure any debris was wet.

First of all, rather than steam cleaning the bottom 1/2 of the engine...I used Brake Clean. I know, but I thought it would dissipate and it was three days ago. IT DOES NOT FULLY DISSIPATE.

Secondly, I ran a test (successfully even), but didn't remove a wire from the starter batt terminal to stud 12. I was distracted when I reconnected the batt positive cable. I left the starter wire connected to the battery positive terminal. NEVER ALLOW YOURSELF TO GET DISTRACTED!!!!

I had my son with me to watch the starter. I went up...pulled the battery switch, and THE ENGINE STARTED!. The starter sparked, Logan said "Kill it". I did. The engine wouldn't stop and the starter solenoid started a fire burning a blue flame just on the top. It ran for about 45 seconds (sounded BEAUTIFUL) but the master was off, I thought the kill switch was still blocking the air, and didn't realize the amount of fuel available to burn. I was on my way back to shove a pillow in the intake when it shut off.

We doused the solenoid with baking soda, and out went the fire. Oddly enough, the starter ground cable is in perfect condition. There isn't any soot anywhere, and all three electrical panels are fine. Stud 12 didn't even get hot in the junction box. Good thing the master was off.

The point of this, other than admitting I made a mistake, is to let you know... You NEVER want to experience the feeling of hearing a 8V71 start when you just turn on the battery switch, standing outside the bus.

It looks like I'm going to have to have it towed after all. I am so angry with myself I can't stand it. I thought if this nightmare can serve one person to be extra vigilant, it's worth the embarrassment. I thought I was anal about safety. I'm sure more so now.

[BIG DOC]

  HAD A SIMULAR PROBLEM. LEAVING FLORIDA AFTER A XMAS TIME AT DISNEY. STOPPED AT A REST STOP FOR A QUICK NAP IN GEORGIA. UP AT 2 AM FOR THE DRIVE. START THE BUS.POUR A CUP & OFF WE GO. ON TO 95 RAMP. FELT A BIT DOWN ON POWER,HEY MAYBE JUST ME. JUST GETTING UP TO SPEED,TRUCKER CALLS ME ON CB SAYING FLAMES COMING OUT THE BACK.GET STOPPED, DON'T SHUT OFF. RUN BACK , OPEN SIDE DOOR,FIRE COMING FROM STARTER (STILL RUNNING). GET 3/8  WRENCH & DISCONNECT AIR LINE OFF SHUT DOWN ON GOVERNOR SO IT WILL NOT SHUT OFF.THE DAMAGE IS ALREADY DONE. THEN SHUT DOWN THE BAT SWITCH.LET IT COOL A BIT,DISCONNECT THE CABLE'S OFF STARTER,BOLT THEM TOGETHER & TAPE GOOD.PUT BAT. BACK ON FOR LIGHTS ETC. COULDN'T GET A 24 VOLT STARTER. DROVE HER HOME  LIKE THAT. CHANGED ALL THE STARTER RELAYS,SWITCH'S THEN.. DOC

[daddysgirl]

Your starter didn't stop spinning when you let off the start switch?
And this might sound stupid, but how did you get it started again...or you never shut the engine down?

[B_K]

From the way I read it he never shut it down until after he was home!
  BK 

And yes btdt!

[daddysgirl]

I am very glad I wasn't going up 95. AND I now understand why the fuel tanks and 8D's are 30' from the engine. NOT going to be moving the batteries now. I am going to have my gas plumber move the LP tanks though

I am just so darn mad at myself. I know better (My dad is in my head screaming)

[bevans6]

One thing you always have to remember with mechanical two strokes is there is no electrical way to turn the engine off.  The only proper way is to put the governor in no-fuel with the engine stop lever.  If you have air pressure and everything works the way it's supposed to, you do that by flipping the run switch off, which turns the skinner valve off, which lets it open and send air pressure to the engine stop air cylinder, which pushes the lever and the engine stops.  If you just started the engine and there is no air pressure, you have to reach past the fan belt (on MCI's) and turn the lever by hand.  The other two ways are to turn off the fuel and let it run until it runs out, or starve it of air.  Using a pillow is a great way to buy a new engine, or a serious rebuild, when it sucks the whole pillow in through the intake and out the exhaust.  FWIW the emergency stop switch works if the dash master switch is off, but the main battery switch must be on.  It takes it's power from the main buss side of the master switch, which is connected somewhat directly to the positive side of the disconnect switch.

Brian

[daddysgirl]

That's one of the "things. The master toggle was off the entire time... and the engine started when I pulled the battery switch on. I wasn't even in the bus. There was no air. BUT I have both inside engine access panels open, and I would have opened the valve lever by hand from the inside before I added the rigid pillow...that I would have tried to hold on to because you are 100% right. I think blocking the air was the only thing on my mind at that moment.
I thought the flap in the air box was still closed because the kill switch was activated last year. It is set up on a spring like return toggle that all else being well, to start it, I have to hold that switch while pressing the start button to reset it (Bill told me that a few weeks ago). That's also what surprised me.

Question: Last year when the kill switch was activated, the engine was running. Could there have been enough fuel pulled in to allow it to run for about 45 seconds???
But I had to close the battery disconnect because it caused the starter to look like the fourth of July...and the fire started.

[bevans6]

If there is no power in the bus (disconnect off) and the emergency stop switch is off, you can just manually re-latch the flap trigger.  I haven't had one for years but I recall it's easy to do, but with a little trick to get it to latch.  I never had to hold a switch, or press the start button to re-latch it, that idea seems wrong.

Do you have the schematic for your bus?  If it's wired correctly power to the starter goes through the master switch, so if it's off you can't start the bus.  It sounds like you have rewire things, and were trying to bypass things, so you achieved that for sure, and at least you know the engine runs and the starter works.  I don't think that fuel or oil could still be present after so long, it's my feeling that you just plain old started the engine, and it obliged by running.  I'd try it again, minus the fire, and see if it starts again or if it ran till it lost prime, or emptied a fuel filter, or something.  With no air pressure none of the engine shut-down features will work.  The only reason it would stop is lack of air or lack of fuel.

[daddysgirl]

When I hold the shutdown switch, it opens the valve behind the blower (the lever with the hole in it).
You would be 100% correct in that the guys who installed the new engine and automatic tranny rewired a few things. I had to clean up the rear panel, and I labeled every single wire, in addition to writing down every stud/breaker/relay location, AND taking pictures as I went. I read the schematics, and a couple of things, like the neutral safety switch is supposed to be wired to the neutral relay and ground..it wasn't. It's connected on one side to stud 12, and the other to the small stud on the starter solenoid. Stud 26 was EMPTY, etc... Been that way since 2000, so I put it back.

Starter switch is NOT connected to the starter. MCI mechanic had me do a test that put the start switch wire to the battery positive (temporary, for a test with the charger cables). I did. My mistake was not removing the starter switch from the battery positive terminal on the solenoid...hence the engine started when I pulled the battery switch, the starter just kept right on cranking, and (I believe) there was just enough brake clean residue to light a blue flame on the solenoid. I've been working on wiring and engine and house systems for over 15 years and three X-Hounds. Each had it's own unique head scratches. I can follow any given wire and 99.9% of the time, figure out what and why it was done. This was nothing but a mistake I made...that I know better than to make. My question now, (after I install all new battery and starter cables tomorrow...that are not melted) is if this mistake killed the starter.

If you know a better way to open that flap (I have access from the inside access panel) please let me know. This is the only time I have ever had to deal with the shutdown, and although a pain in the butt at this moment, I was taught to never bypass safety systems. As you noted earlier, there is no electrical shutdown mechanism. And I'm really grateful for the advise. If I'm not learning something every day, I shouldn't be operating a bus