I'm a big dope

I would be hugely surprised if it turned out that you damaged your welder. That DC starter solenoid probably did not engage at all with the polarity reversed. Worst of the worst case may be that you damaged that solenoid, highly unlikely though.

The battery, though, is another story.

I had a chance to download and look over the electrical schematic of the engine and welder and I think you are spot on on your comment. I replaced the battery and the engine now cranks but still doesn't start. I drained the gas tank, replaced with fresh fuel, checked the fuel filters, cleaned the carb, replaced the plugs, checked the oil level and air filter; but it still wont start, very frustrating! I'm not sure what to try next? rick

Ignoramus5766 wrote:

You may have fried the (presumably) electronic ignition :-(

Mark Rand RTFM

Do you have spark? And check the timing.

Snicker - let us hope it was like me :

I forgot the choke on the other side of the machine!!! Put it in the start mode and zoom. I almost pulled my arm off until I got a brain to really look it over - all sides since last time.

Martin

Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member

semidemiurge wrote:

Will it try to run if you give it a shot of starting fluid? If so, the orifices in the carb might be gunked up from the old fuel. This has happened to me more than once. Jim

Um, how about listing the symptoms. Does it crank, does it make noises like some fuel is firing, is the fuel coming to the carb, does it start if you simply add a spoon of gas to the carb, etc etc.

It needs three things to run: Fuel in the cylinder, compression, and spark. What is missing?

Pull the plug and attach the plug wire. Lay it against a ground point, Crank it and see if there is a spark. If not, you probably damaged the ignition circuit.

Put your finger over the plug hole and crank. Do you get pressure?

Spray some starting fluid in the carburetor and crank. Does it fire?

Try these and see what you find.

Tom

Well the story gets even better :) I bit the bullet and pulled the carb, it wasn't very dirty but I cleaned thoroughly. I thought I would try testing the fuel shutoff solenoid by connecting it directly to the battery and it would not energize when directly connected. I got the multimeter out and decided to test the battery6 volts!!! I had been sold a 6volt battery not a 12 volt! The battery was smaller than a normal automotive battery so the salesman must have gone on size only. This would also explain why the fuel gage wasn't working properly (it apparently needed 12 v). The funny thing is that the battery cranked the engine fine and it would sound like it was almost ready to fire up. The 6v just wasn't enough to energize the fuel cutoff solenoid. So after exchanging the battery it fired right-up ;) The battery label had no indication as to its voltage, which I thought was strange. It was a good learning experience despite all the waisted time and effort. Thanks for everyone's help and input. rick

I thought that fuel shutoff solenoids were on diesel engines only???

(I have one in my Onan DJE generator).

Congrats!!!

Why would it care? Although there's a bit of residual magnetisation in those things, they're just soft iron cores, not alnico.