Lawnmower /small engine guys

I've a briggs 300E engine on a push mower. Won't start. No spark.

Is the electronics embedded in the coil?
just

I have worked on a lot of those motors. Never replaced one coil.

That machine has the plastic carb on it. It was always the carb ---- every time.

The lack of spark would make me think it has more problems than a bad carburetor

if you remove the top cover/recoil starter the brake and kill switch is at the back and is actuated by the safety lever and cable , the flywheel for lack of better term gets rusty and you need to clean the magnet and the coil then you place a business card in between the two to set the gap and tighten the coil back down , remove the card and pull it over and see if you have spark , you have to have that safety lever pulled over to take the brake off and not have the kill switch on.

Safety lever cable can stretch,also. Won't let it fire. Bypass it temporarily ,and see if it fires.

That's the same method my dad taught me for setting the coil/magneto.

Concerning the carburetor... Mine has the little plastic one with the jet cartridge in it. I kept having problems with the crystallized slime clogging the jet. I finally pulled the gas tank, hose, carb, etc... and cleaned them all back to factory clean... Then I started using Tru-Fuel and haven't had any issues since. It's a bit expensive to run that stuff but the flawless performance is worth it. When I go to work on the yard, I want to work on the yard... Not the mower.

Mike

I'll check that switch tomorrow. Tried the old screwdriver in the plug wire and hold on. felt nothing.
Better change the gas.
This is our back up trim mower. Hasn't run for a couple of years . haven't needed it til now.
Rust could be a problem now. There was no rust a couple of years ago when we first had the problem.
thanks for the info guys.
just

startron is what I have gone to and 91 octane no ethanol http://www.starbrite.com/item/star-tron-gasoline-additive?category_id=586

one ounce treats 6 gallons and it is hard to pour much less than a half ounce so that is about what my 2 gallons get , the bottle says you basically can't over treat, I use mixed gas in everything it is just easier to have one can and keep it fresh and treated.

I had started using startron in 2018-2019 then my mower got left out all winter snowed on it started snowing in October and I was imagining it was going to be a mess I started pulling through slow to just turn it over and it popped off and started on the 2nd pull after being under a foot of snow all winter , I was sold
then in 2020 I was cutting a neighbors tree May 6th , and May 7th had a blood clot and didn't pick my saws up again till mid November, 2nd pull and my saws fired right up. so now startron with every Can in the small engine stuff.

those little plastic carbs have a diaphragm and gasket between the carb and tank that was usually my issue with them replace that clean the carb with some carb and choke and dump the gas tank and clean it out

I have 4 of those little mowers over the years never paid for a one of them 3 co-workers gave me because they would use regular 87 E10 and they would be a gummed up mess in the spring they would go buy a new 129.99 mower and give me the old one. or they had used it for a few years then had an issue. and one I got when my grandpa passed and no longer needed it.

could go around on big garbage day week and get them off the curb if you were fast enough to beat my old neighbor he would cruse around with a trailer slow rolling town , then take them all back to his house and get as many running as he could , parts from the others he always had 3-4 mowers for sale on his front lawn

I too like startron.

Have one of the plastic carb mowers. Every time I try to use it the carb needs cleaned.
To the point the carb is held together with drywall screws,

My plan is next time I touch it it gets new carb and run dry every time.
Most contrary carb I've seen. Mower is like new.

It was used too much when it was new.

Startron and 91 with no ethanol has made an incredible difference on my stuff. Small engines, boats, snow machines all fire right up after storing, no problem. Haven’t had a carb off in a long time and that used to be a common practice around here. My old Enticer snow machine sat for three years in Canada with startron treated fuel. Primed each cylinder with gas and it started and ran like a top. I always had to pull and clean carb almost every year before.

I'm not saying it doesn't have spark issues, but I never replaced one coil on those motors ever. That plastic carb was the issue every time. I can clean them blind folded.


I spent 4 years working on small engines at a hardware store, and ran a repair shop out of my garage at home for about 3 years before that. If I had a dollar for every time someone told me that it "didn't have spark" and it was really bad gas - I would be rich. That is a go to response for 99% of people. It's because 30 years ago when your lawn mower didn't start It was a spark issue.

When I put my small engine machines away for the season, I always add Sta-Bil to the gas and let them run for awhile before I store them. I never have a problem getting them to start when I next start a new season.
I've never done this, but I hear some people disconnect the gas line to the carb and let the engine run until the carb is empty. They say that works too for starting the next time they use it.

Totally agree with everyone that on today's small engines, fuel is 99% of the time the prob. It's cool that I'm old enough that when I started piddling with them about 28 years ago, It was plugs or points bad. But if he can hold a screwdriver in the plug wire onto flesh, that's a cause for concern. Remove spark plug, and snap it into plug wire, grounded against the engine, at dark will be easy to see.
If you don't have spark, #1 issue is kill wire. As others have mentioned, letting go of safety handle kills mower. It is a small wire that plugs onto coil. Follow it from coil, to the switch and stop brake. The cable from handle attaches here, and letting go of the handle allows a spring to pull brake onto flywheel, and a little arm contacts wire grounding the wire and killing the coil. If you unplug that wire from the coil, and it starts, that wire is grounded somewhere. Most likely melted the plastic off the wire near an engine fin. CAUTION: you wont be able to kill the engine unless you pull off plug wire. Let us know how it turns out

The aluminum key in the flywheel will cause it to not have a spark and is over looked by many.

An engine with a sheared key will have spark, it will just be out of time, so that it won't start.

Throw the old lawnmower in the dump and go down to wal mart and buy a new chinese one for 125 bucks or less.
It,ll run good for a couple or 3 years with cheap gas,then go buy another one.
My old one was still running OK but the wheels fell off from rust.Probably from storing it in a snowbank for 7 months a year

last time I needed parts for my aunts mower I went to the dump , she had worn out a wheel I picked up 3 more off a very similar mower and replaced the pair on the front so that she would get an even cut

99% of the time you don't even have to work so hard as to take it to the dump around here write free on a piece of paper tape it to the handle and roll to the street/road it is unlikely to be there in 24 hours and it saves you loading unloading , paying , or any more work than getting it to the end of your drive way

It'll leave faster if you put $25 on the sign.
Works for tires too.

Got an old lawn boy I want to refurbish if I find seals and carb parts.
They were the best.

depends where you are at , here if it has no sign at all most people will walk up to the door and ask

lots of people fix and sell mowers around here so not uncommon to see 2-3 in a front yard with a sign for 40 dollars each and very few get stolen

we have a lot of honor system firewood also

my cousin has an honor system pay what you can vegetable stand he makes more than he thinks the vegetables are worth often.

maybe that is why I still think this is a great place to live.

I am not saying theft doesn't happen but generally low value large to move and hard to sell items aren't the target

One of the local guys here sells fishing minnows.he works all day so he has his minnows in a cooler outside,and a drop box for the money.People who dont trap their own fishing minnows will go and get minnows there and leave the money in the box.
An honor system that works when people are honest.

Switch is OK. Pulled the coil and cleaned the rust from the fly wheel and coil. Now I have spark.
Still don't start. Got a new carb ordered. We'll see.
total cost so far $1.86 for spark plug.
$16.-00 for carb.
Fresh gas ???
just

You pricing your labor/time?

Boco, some people like to tinker. To be honest I think like you do.

There are quite a few guys that like to work on small engines.
I give stuff to one fellow here,he uses them for parts if he cant fix them.Especially old chainsaws.
I had him re build a skidoo engine for me once,real reasonable price and great work,quick return.
He has a shop and tools and likes working on stuff,I dont have the tools or time,not to mention I am not that good at tinkering with engines.

squirt bottle with a little fresh gas is a great tool the small engine shop in town uses the catsup and mustard bottles I use something like this i got for a couple dollars at a restaraund supply store and used for other stuff for years then when I needed it for an engine it got repurposed.
https://www.amazon.com/New-Star-Foodservice-26238-Squeeze/dp/B009LS6QQY/ref=sr_1_1_sspa?gclid=Cj0KCQjwzLCVBhD3ARIsAPKYTcR8BvEEvHD-eA1G4JsEt5P8jIL7RZvzsunOZGNR9_CVs6izoLO-TUkaApQdEALw_wcB&hvadid=241609188843&hvdev=c&hvlocphy=9018907&hvnetw=g&hvqmt=e&hvrand=16621096280273789518&hvtargid=kwd-2995829023&hydadcr=13959_10210617&keywords=mustard%2Bsqueeze%2Bbottle&qid=1655493531&sr=8-1-spons&smid=A1XRDHEV66IVUP&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzUVlTM1hYREJUOVZEJmVuY3J5cHRlZElkPUEwNjc1NzIxMjRCRk1GVEhBSDg4SSZlbmNyeXB0ZWRBZElkPUEwMjk2NTc1M0c2VkRNVlEyVVJXTiZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1

I dump it out into another implement after every use so it is always fresh gas and I am not storing gas in the bottle I only put a few ounces in but it lets you dispense a little gas into the carb opening very hard to pour jsut a little gas from a can and it leads to other safety concerns. I know a guy who was pouring gas form a Styrofoam cup into a car carburetor to make it run like that and the car shot flames up the carb then he was holding a fire ball in his hand could not drop it fast enough.
so squirt a little , step back pull start cord see if it pops off if it does then carb is the right direction to go.


edit: I know a guy who was pouring gas form a Styrofoam cup into a car carburetor to make it run like that and the car shot flames up the carb then he was holding a fire ball in his hand could not drop it fast enough.
Just in case pouring from a cup wasn't a bad enough idea , gas dissolves many Styrofoam cups very quick. don't do this bad idea