There are a few different styles of carb used on small engines. Briggs uses the diaphragm carb mostly on lower end engines using tank mounted carbs. Your carb is a "bowl type", used on their larger machines, generally. They don't feature a diaphragm.

The fuel line you're using sounds like "Tygon". It'll do. Probably you replaced a 1/4" rubber fuel line with it. The tygon will stiffen some, and tends to yellow, it's the nature of the beast. Some bubble is normal in the fuel line, fuel still gets past.

You still have a clog in the carb. Probably in the brass "bolt" that holds the bowl on the carb. This piece generally has small holes bored around it's perimeter in the threaded area, and these commonly clog. Poke'm out and hopefully things will cooperate.

J

In the morning, I would just let it idle for a bit to burn off any oil which might have mixed in. The smoke should clear in a bit..

Awesome!

Yes, the oil should burn out of the muffler in short order. Smoke generally stops in a minute or 2.

If it doesn't smooth out then, post back and we'll see about fine tuning.

Just thought to add this: If you still have that sea-foamed gasoline in the tank, some smoke will continue until that tank is burned. Sea-foam tends to cause some smoke while running. No worry.

Nice work!

J

Yep, still had the SeaFoam gas in the tank. Added some more fresh gas. Started pretty easy, less smoke than before, let it idle several minutes. Sounded sort of 'puny', not robust like before. Went ahead a MOWED THE FRONT LAWN!!! It did cut out on me several times - even though the grass was not thick or heavy. Restarted easily. After I finished mowing, I let it sit and idle for a bit. Still some faint smoke, but not much. It just doesn't sound quite normal. It seems to struggle a bit - maybe a little lean?

Sounds a touch lean, perhaps... Though there is usually no smoke with lean, it could be rich...

Is there an adjustment (needle valve) on the main jet (the brass bolt that holds on the float bowl, which was the culprit in the beginning)?

If there is, we can likely tune it out. If not, the only recourse is more cleaning, or more seafoam...

J

Didn't get to work on the mower tonight. Should have time tomorrow.

I don't remember seeing any empty threads in that brass float bowl screw. I'm sure I didn't lose any parts taking the carb apart either. Learned my lesson a long time ago on parts control.

In the body of the carb there is something with two small passages. It is brass too and held in place by a recessed snap ring. That and the brass float bowl screw fit together. I didn't take the snap ring out, but I was able to run all through the passages with the wires and carb cleaner. Maybe that wasn't good enough?

There is still some SeaFoam in the tank. The slight smoke rises and it is whitish. After I shut down my PC last night, I kept thinking about it, and the times that the mower shut off. How during the whole time the mower was running, it seemed to be running at the same speed. Maybe I crowded the linkage a bit behind the air cleaner - maybe?

So, I am wondering if it might be good for me to take the air cleaner off again and check that linkage. I should be able to recognize if I pinched it or not, and if it is still connected. Beyond that, I don't know what to look for. If that is okay, would it sound reasonable to see if it will run itself out? I could put more SeaFoam in, if that might help. I have a smallish back yard left to mow.

What do you think?

Thanks,

Linda

Checking that the linkage moves freely wouldn't hurt. Check that you've got the governor spring in the right holes. Hopefully those were noted when you disassembled.

Ultimately, the governor's job is to keep the engine at a constant speed. It just gives more throttle when the engine slows, and closes the throttle when the engine speeds.

If the governor is disconnected/connected improperly, the engine will often run just on the idle stop screw. That _might_ be what you're experiencing.

It would, to me, seem reasonable to see if it improves over a tank or 2. If not, revisit then.

J

Doggone it, I'm back again. Same mower. After really getting it cleaned up (following all of the suggestions), I did find out that the station where I had been buying gas, had gone to the ethanol mix - no label on the pump, either. So, I bought no-ethanol gas wherever I could find it, and the mower ran fine. Now I can't find anymore non-ethanol gas anywhere close to home. Now, it's Seafoam added all of the time, get one mow done, break it down, clean it up every time before I can mow again.

Am I missing something? I can't afford to replace the mower, and I guess I would probably have the same problem with the next gas engine? Have you/anyone found a workable way to manage this kind of problem?

Thanks in advance,

Linda

I have numerous 4 cycle mowers (7) and 2 cycle trimmers that were used quite a bit when we had rental properties.

This is what I currently do as a norm:

Always 1oz Sta-Bil per 5 gallons of gas; sometimes I'll use 2oz Sta-Bil per 5 gallons.

In addition, I add 5oz SeaFoam per 5 gallons of gas; the next 5 gallons I'll use 5oz of Chemtool versus the SeaFoam.

I check/clean/gap or replace the plug (if necessary) after approx 30-40 hours of usage.

Obviously, keep the filter(s) clean.