Shop Time w/T.W. Friends

OK shop guys. I’m not a wrench man like you all I just kinda know how to turn a wrench once in a while. I got this small motor genny that backfired (or after fired) when I shut it down and then proceeded to pile oil out the carb. This is the mole patrol gasser rig I showed you guys that has been working wonders on my vermin.
So the foam filter was soaked in black oil so I cleaned it and the carb with starting fluid. Checked the oil and Sprayed a couple times in the carb and the machine started up and ran for a good 15 minutes before I shut er down.
Now there’s a couple variables in play here
I been running it on half choke to smoke show the tunnels
I welded on a stick of pipe and a silicon hose
This particular time I had mounted it to the back of my tractor. I ran across the property while it ran fine. This was after smoked all the tunnels and was running it lean before shutdown.

Got to the garage and was ready to unhook it and put it up. Once I shut it down it backfired and spit out a black soot spot on my driveway outta the hose. Then it started puking oil from the air cleaner.

Is there anything I should be aware of or just run it and keep oil in it? Maybe not so much choke and run it more lean?

 

More pics

 

Theory:
By running with the choke on you are accumulating carbon in the exhaust system, the longer pipe adds to this as well.

That carbon makes hot spots in the exhaust, when you turned the ignition off the engine still processed a few revolutions of fuel/air with no spark putting a bit of raw fuel in the exhaust - with the carbon hot spots = backfire & soot spot.

The oil in the air cleaner may be from the engine briefly turning backwards from the backfire - the crankcase vent might go into the air cleaner. Could be from riding on the tractor while running too - the crankcase vent on generator engines might be a bit different as they tend to be stationary and at a single speed in use.

Also check the oil condition, running rich might be diluting with gas.

 

I'm gonna free associate here.

Running with the choke on will increase the vacuum of the engine.

The engine has a reed valve in the block that allows un burnt vapors from the crank case to be pulled into the carb throttle body to be burnt. I'm betting vapors and oil got pulled into the intake. Depending on the orientation of that engine, there could be quite a bit of oil pulled into the carb throttle body.

Because the engine was running at a vacuum ( low pressure), a fluid(oil) will want to be pulled into a lower pressure area. I'm guessing there is nothing wrong with the engine, you just need to run it full throttle with no choke.

Obviously squeeze the filter as dry as possible and make sure oil level is correct.

I'm not good at explaining, but when an engine throttle is choked off, the engine will get air from any place that it can. The crank case is the 1st place that has access to any air.

If you have ever noticed on many choke butterfly plates, there is often a small notch. This is on purpose so seals are not compromised. Seals are good at dealing with pressure , but not good at not pulling in and leaking because of excess vacuum.

 

i've had a few different small engines like that end up with soaked air filters--i think all of them with the crankcase return end up like that. so not really a symptom so much as a condition of it's functionality.

like kodiitten mentioned, there's a return into the intake on there to 'burn' crankcase vapors(most of the motors i've taken apart like that, it seems to do more to burn oil than vapors, but engineers must know something i don't). but also to prevent gasses from building up within the crankcase. they're all relatively simple motors, with relatively loose tolerances-- they're all built to 'work', not work efficiently. some will still run at compressions as low as 40 psi, where automotive engines, anything less than 100psi is mostly dead(that 'big ox' snow blower i repaired a few years ago ran something like 45psi compression-- i spent a ton of time thinking the rings were shot on it, where i really just had a bad coil). most have a ton of blow-by, and after excessive use, you could almost take the old oil out and run it in a 2-stroke.

it's definitely not helping putting that much back pressure on the exhaust. i would suggest you purge it after a smoke session-- just run it un-choked, and without your tunnel adapter for 15-20 minutes to try to clean things up before storing it again.

and if you're trying to smoke them out, it could also help to add a little transmission fluid to the gasoline.

 

Another pic to show the carb orientation
This genny was given to me as a salvage from a barn burn I demoed a couple years back. I guess Firman is a common Lowe’s brand of genny and don’t know its origin. But it’s a good running little motor with low hours. The folks I got it from said it only had like 4 hours on it before the fire.

 

Happy Birthday @Hunterdc1 !!

 

@soundman98
I see what you are saying and I bet raising the suspension pulls the diff on center from the bar.
Like anything else in the custom world. It works. Maybe they couldn’t find a spot to mount with
The correct geometry.. I’ve played with enough geometry in the race cars to know if it’s not right, it’s not
right. Weird shit happens. So I guess it’s the wow factor here and not performance. But still..

 

The machine is not designed to do what you’re doing with it. It’s gonna have these issues. Many years ago I built a fogging machine out of a push mower for mosquito control. Motor was not affected. Basically a drip tank into the exhaust. Smoked a parking lot like nobody’s business. All from a 3 1/2 powered push mower. You can then use different “stuff” in the tank for your smoke. Not hard to do….

 

Morning all have a great day back to work for me
@Hunterdc1 happy birthday

 

Happy birthday!

 

Happy Birthday @Hunterdc1
I hope you do something you enjoy today

 

@Hunterdc1







37 huh

 

so, in honor of the youngster @Hunterdc1 I grilt up sumpin special just for you!!

 

Happy Saturday morning, friends! Hope everyone has an awesome day


Happy birthday @Hunterdc1


The shop crew tried to put together a little and was going to get you something special. We searched high and low for all we could get, we looked high on door jams for pennies and low under the couch for 1/4’s.

We put all we found together and got you this nice

Enjoy!

 

Good morning and welcome to the weekend everyone

Happy birthday @Hunterdc1 , from that last pic you posted, looks like your liviin the dream

I hope you have a wonderful day and wanted to say thanks for your work posts. Unprecedented info from my distant perspective

Unrelated, RIP George Foreman. A truly unique American.

 

Happy bday @Hunterdc1

 

Happy birthday, @Hunterdc1!

 

I know there are better boxes and you get what you pay for, at the moment that one will be better than this one and I can put this top box back on the other one and let Cole have it.

I bought the Craftsman boxes in the 1990’s new.

 

My parents came by yesterday because my dad wanted to give this to my son. Cole is the only male in our family of his generation.

This pistol belonged to his great great grandfather (my great grandfather). He was a sheriff and this was his duty weapon. He died in 1957.

As my dad told Cole how he got this gun he had a tear in his eye, it’s the 4th time in my life I’ve seen my dad tear up and I’ll be 50 this year. He’s a tough man and been through a lot.

Dad’s grandpa gave this gun to his dad, dad lost both his parents in a car wreck when he was 12. Dads uncle (who my dad and his sister lived with after the accident) took the pistol and kept it until my dad was 18 and gave it to him.

I’ve never heard him talk about it, it honors me dad gave it to my son and not to my brother or me.

It’s a smith and Wesson .38 serial #432xxx

Anyone have a book they can tell me what year it is? @JimBeam maybe? I’ve looked online and can’t find specifics, only ranges.

Don’t care what it’s worth, it’s priceless to our family.