Briggs and Straton help

[Ken Cunningham]

Dump some seafoam in there and see if that helps. A clogged carb will cause hunting. The engine wont get enough fuel, so the govenor opens up the throttle to dump more fuel in, then its running to fast so the govenor closes the throttle, then the cycle starts all over again.

 

[mostly_gas]

Sounds like a fuel supply or mixture related issue. Check plug for fouling replace if questionable. Check fuel lines for cracking, flaking and at 10 yr old I would replace. If fuel lines clean, check for intake leaks, if none then pull and disassemble carb, looking for sediment. Typically a stretched spring will change the operating RPM but not cause fluctuating RPM.

 

[bp fick]

I rebuilt a carb off a tecumseh this winter for my neighbor's snowblower. I actually found a lot of rotted out rubber seats and rather plugged up passageways. My guess is this. With the use of so much plastic instead of the metals and brass of by-gone days, it doesn't take much. (ethanol doesn't help!!). I have had two push mowers consecutively that were B&S, fixed throttle and plastic carbs. Again, it doesn't take much for them to start with the "hunting" or oscillating rpms.

Sometimes I kit them, sometimes I just replace the carbs. Start with a cleaning and a kit. If you have to replace the carb, shop til you drop for the best price.

We all want low prices on these small engine devices and we are typically getting more and plastic and less and less durability, imo.

 

[emmy71]

Lots of good advice. I will check out the carb good this weekend and update.

Thanks,
Terry

 

[emmy71]

I managed to have some success today with the lawn mower. I believe I had multiple problems and have most of them fixed. The fuel line was old and cracked so I replaced it. I believe the float was hanging up some in the up position so I imagine that the carb wasn't getting a steady supply of fuel. I cleaned that and the rest of the carb with the spray carb cleaner. I did not have a lot of time to spend on it so I had to give it a quick cleaning but I do plan to disassemble and clean out all the varnish. I also believe there is an intake leak so I will make a new gasket for it. It now runs really well under load. It still hunts a little with no load but not too bad. Thanks for everyones help.

Terry

 

[schmism]

some of the newer carbs are a plastic body and they warp and crack over time. when that happens they run lean and will surge (or hunt). usually a replacement plastic carb is only a few bucks.

i wish you could get an old school metal carb with manual choke and throttle.

Quick story about these new fangled versions with no choke or throttle. had a neighbor with one could NOT get it started in spring. he fought with it for over an hr. (new gas, plug etc)

i walked over, took the air cleaner off, put my hand over the intake pulled the rope twice and it coughed to life while i manually ran the choke with my palm.

after 30 sec or so it was running full bore, put the air cleaner on and he mowed started pushing around the yard....

 

[Bobby R]

Why don't you try putting high octane gasoline in it. My pressure washer did the exact same thing and someone suggested going to a higher octane fuel. This eliminated the problem. The 10% ethanol they put in regular gas is not good for small engines, and I'm told will eventually burn them up.

 

[bp fick]

duplicate

 

[bp fick]

Old thread, but....


If an engine isn't designed for octane higher than X, putting higher Y octane in is usually not worthwhile. Also, most of the ethanol gas around here, anyhow, comes in both regular and premium. Most all of it has ethanol.

 

[Deere Dude]

Why don't you try putting high octane gasoline in it. My pressure washer did the exact same thing and someone suggested going to a higher octane fuel. This eliminated the problem. The 10% ethanol they put in regular gas is not good for small engines, and I'm told will eventually burn them up.

X2. I had problems over the years with chainsaw and mowers and snowblowers, pressure washers etc. and then my brother-in-law who is a stickler for keeping that stuff running good said to put the highest octane gas with no ethanol you can find in it. Throw a little sea-foam in to help it. Everything starts on first pull almost and ruins smooth where everything used to hunt and cycle and start hard. I always used to go to regular unleaded with ethanol that I would use for the car because it was easy and cheaper. Not any more. A few gallons of premium gas lasts a long time using it on those type of engines anyway. :thumbsup: