New Briggs -- I'm stumped

Status
Not open for further replies.
H

Hokiefyd

Joined
Jun 24, 2004
Messages
14,505
Location
Top of Virginia
I have a co-worker's mower for repair. It's the newer "value" or E line of OHV Briggs engines that replaced the old flat head "Classic" line. No start. It has fuel in the tank. Primer gets no fuel to the carburetor. Okay, got it. It should at least cough on starting fluid...that would confirm ignition. No cough at all. Pull plug and cord...the plug does spark (strong). Hmm. Check flywheel key...that's good. Check valve lash...that's good. The engine feels like it has compression. It doesn't feel super tight like an older Lawn-Boy 2-cycle, but it feels decent. Governor arm seems to work right...throttle is wide open at rest (as it should be). There is no choke...just a primer bulb.

So. It has air. It has spark. It has fuel (aerosol carb cleaner). It should be timed correctly (good flywheel key). It feels like it has compression. I'm not sure if the head is removable on these newer engines or if they're a "uniblock" like the Honda GCVs. I'm thinking that it's got to be a mechanical issue in the engine. But even if it were missing a ring or two or even had a hole in the piston, you'd think the carb cleaner would at least "pop" with the spark, right?
 
What lead up to the no-run situation?

Even if the spark looks strong, I'd try a new plug anyway. I'd also flush the fuel system with new fuel, just to take those two possibilities out of the equation.

As far as I know, the real basic flat heads with the pepper shaker mufflers still exist on some low-end make/models. I've seen some brand-new ones in stores like this, this spring.
 
Last edited:
why not try a little gasoline in the cylinder? I use a squirt oil bottle to start my Snapper (bad carb)....I remove the plug, squirt a little gas in the cylinder, reinstall the plug and away she goes.
 
Originally Posted By: Donald
I did not think the newer mower engines had any engine control. It may have a choke, but its automatic. My Kohler Courage has that.

Should pop on starter fluid.


It has a primer bulb. Therefor, it doesn't have a choke. The primer bulb replaces the choke. The spray you are using may not be as flammable as you think. Try a squirt of gas directly in the carburetor or spark plug hole.
 
As was stated try using either gasoline or starting fluid to see if it will fire up. If it fires up check for either a clogged fuel line, inlet needle, bad carb mounting gaskets etc. Some of those with a primer bulb you need to press the heck out of it before anything happens... i'm talking like 20+ presses on it. After you try to start it and remove the spark plug do you smell any gas, or see a wet spark plug? If it's dry and no gas smell then you simply aren't getting any fuel.
 
It's not clear, are you really using starting fluid or are you using carb cleaner?

Between that and "Primer gets no fuel to the carburetor. " meaning to me no actual gasoline is getting into the engine it sounds to me like a fuel issue.

Still I would compare pulling the starter with and without the spark plug to get a better feel for compression.
 
Last edited:
Thanks, will try these tips.

I have no back story on it. My co-worker brought it in, but I believe it's actually his neighbor's mower. It's a year or two old I believe. It's ran before because it's got grass clippings on it. They took it to an automotive garage where they live and they tried a few things, but apparently didn't know the root cause. The plug in it now is brand new...I can tell that it hasn't been run before.

If I can at least get it to cough, I'll work further with the fuel system. I am using real starting fluid. I always keep a can or two of that handy for working with small engines. That's usually my first move: if it catches on starting fluid but then quits, it's probably a carburetor problem. This one doesn't even catch, so I suspected spark, but there is spark, and appears to be strong spark. I may try a new plug anyway. I'll also "feel" the rope pull closer to sense compression. My gut says that there's a mechanical problem inside the cylinder.
 
Originally Posted By: Hokiefyd
Thanks, will try these tips.

I have no back story on it. My co-worker brought it in, but I believe it's actually his neighbor's mower. It's a year or two old I believe. It's ran before because it's got grass clippings on it. They took it to an automotive garage where they live and they tried a few things, but apparently didn't know the root cause. The plug in it now is brand new...I can tell that it hasn't been run before.

If I can at least get it to cough, I'll work further with the fuel system. I am using real starting fluid. I always keep a can or two of that handy for working with small engines. That's usually my first move: if it catches on starting fluid but then quits, it's probably a carburetor problem. This one doesn't even catch, so I suspected spark, but there is spark, and appears to be strong spark. I may try a new plug anyway. I'll also "feel" the rope pull closer to sense compression. My gut says that there's a mechanical problem inside the cylinder.


This is a bit unusual but it can happen: if the ignition voltage is very weak, it might spark OK with the plug removed but not spark at all when the plug is in the cylinder and under compression. Its harder to get a spark in dense air than at atmospheric pressure. If its really not firing at all on starting fluid, then I'd go back to spark. Got a spare magneto lying around?
 
If it's under two years old there's an EPA emissions warranty on the carb and other stuff. Maybe try a legit briggs dealer?
 
Many of those primer bulbs pump air and they get a tiny leak

try about 15-20 presses on the primer bulb.

Its not like old school primer bulb you see on a leaf blower or string-trimmer.(IIRC)
 
Last edited:
Reduce the spark plug gap to .020. Is the oil grey with metal particles? Is the compression at least 50 psi? Stuck intake valve? Sheared flywheel key?
 
Originally Posted By: JTK

As far as I know, the real basic flat heads with the pepper shaker mufflers still exist on some low-end make/models. I've seen some brand-new ones in stores like this, this spring.


Earlier this spring, I was walking through a local Walmart and sure enough, their entry-level model still uses the B&S flathead engine that's basically been around for decades. It was my assumption that they no longer were allowed to manufactured them, but I assumed wrong. I will probably pick one or two of them up on clearance this fall and hopefully will have a lifetime supply of a cheap mower that has plenty of replacement parts available.
 
It's fixed. Two problems. First, the engine was massively overfilled with oil. The plug was not wet when I pulled it, but I figure that there was enough oil in the cylinder to soak up the starting fluid. After draining the oil and pulling the rope a few times, it coughed on starting fluid. Nice!

Next was looking at the primer. The bulb was fine, but it was pushing air out a little side vent rather than pushing fuel up into the carburetor. I cleaned the carburetor and reassembled and checked primer operation. Good. Put mower back together. It runs. Success.

And for a flat cost of zero!

This is the first of the newer OHV E series engines I've used and I like them. They're small (140 cc), but they're smooth and pretty quiet. And dead simple. Give me a small speed control lever on the engine like the Tecumsehs had and I'd want one!
 
Originally Posted By: Hokiefyd
This is the first of the newer OHV E series engines I've used and I like them. They're small (140 cc), but they're smooth and pretty quiet. And dead simple. Give me a small speed control lever on the engine like the Tecumsehs had and I'd want one!


I've never worked on THAT particular engine, but every other Briggs push mower engine I have ever seen, you can up the RPM's by simply bending a metal tab that is attached to the governor spring. Kick the RPM up to 3200 RPM instead of the factory 2850 and you will have a real runner on your hands.
 
I fixed one of these and sold it on a Bolens recently. Run the engine dry when storing it. The carb clogs up easily and leads to no starts and surging. Other than that it runs fine once it is running.

I'm not sure how it holds up long term. The flathead holds out pretty well and is time tested. The lowest HP flathead, the 3.5hp one, probably uses so little gas because of displacement that it probably still complies with emissions.

If they can continue to sell them they will continue to produce them, that engine has been around forever,
 
Originally Posted By: Hokiefyd


This is the first of the newer OHV E series engines I've used and I like them. They're small (140 cc), but they're smooth and pretty quiet. And dead simple. Give me a small speed control lever on the engine like the Tecumsehs had and I'd want one!


Did you see my "fun little re-engine project" thread? I ordered a replacement Briggs 190 CC (6.75 ft-lb torque) engine and put it on an old high-wheel deck that had originally had the smaller 158cc flathead. I left it the way it came from Briggs with an engine-mounted throttle only- no controls whatsoever on the handle. Old school :-)

Anyway, I assume this is the OHV engine you're talking about. I see it has a float type carb- and to me that's the deciding factor in its favor. In hindsight, it might have been a great choice for my re-engine project given that its so much lighter than the 190CC engine. But its a little more expensive.

The small Briggs flatheads still use a diaphragm (Pulsa-Jet) carb, and I've made a solemn vow to never use one of those again. I do still own a 2-horsepower rated "slant carb" Briggs from circa 1958, but its a "vacu-Jet" jet carb that's not nearly so quirky. And it has a manual choke.
 
Originally Posted By: man114


If they can continue to sell them they will continue to produce them, that engine has been around forever,


The 190cc flathead is my favorite walk-behind engine, bar none. Not the most powerful, not the lightest, but smooth, QUIET, and pretty uch bulletproof. Its still available in a lot of configurations. I doubt its going out of production anytime soon.

The little "pepper-shaker muffler" (I like that) 158cc flathead is only in 4 shaft configurations, at least through Equipatron. But still kicking for a little while longer, anyway.
 
Status
Not open for further replies.

Similar threads

buck91
  • Locked
Poulan repairs
Replies
6
Views
3K
buck91
P
  • Locked
3.5 hp Briggs and Stratton hard to start when cold
Replies
4
Views
16K
yeehaw1960
cwilliamsws6
Briggs 3HP 80292 magnetron conversion?
2
Replies
22
Views
6K
wag123
jeepman3071
  • Locked
No start - flathead briggs and stratton
Replies
15
Views
23K
TFB1
D
  • Locked
B&S 8.5 OHV snowblower almost runs....
Replies
14
Views
18K
Nick R
Back
Top Bottom