Briggs and Stratton16 hp OVH Engine Surges/Runs Bad Pops Throughout Intake.

[Mower King]

Sometimes popping through the carb can also mean valves out of adjustment or a valve train timing problem also, besides the carb......really need to try to isolate the problem or it's easy to chase everything, and get nowhere!

Always check spark plug 1st, if it don't fire right, not much else works right.....and it's super easy to check / change!

 

[Scrubcadet10]

280000

OHV Single Cylinder

.003 / .005 Intake

.005 / .007 Exhaust

Valve clearance.... is that what you set them at? basically .004" and .006"

 

[StarTech]

A couple things to check also.

• Is both rocker arms moving the same amount. A worn exhaust lobe on the camshaft can cause back pressure at the carburetor. I just one this that ran extremely poorly and actually sounded like it needed a muffler until I pulled the air filter and then it had back pressure coming out of the intake. I then check the rockers and found the exhaust barely moving. New camshaft fixed the problem.
• Another possible source is the intake seals. I had one last year that that sounded like it was sneezing and the o-ring at the head was leaking air.

 

[seattlepioneer]

<<I had the carb and lines off like 100 times already never had this much trouble with such a simple engine.. unless there is something i am missing inside the carb. Does anyone know a good aftermarket carb that has worked for them? debating on getting a new one but oem is like $120 thats more then i paid for the mower lol. >>


I'm not an Xprt, but when you find yourself doing the same task repeatedly, it's probably something else that's the problem.

I found myself with a similar problem that led me to believe the engine was being starved of fuel. Naturally I cleaned out the carb repeatedly, cleaned out the fuel tank, replaced the fuel line -----no improvement.

So what's left? As it turned out, the intake manifold that carried the fuel/air mixture from the carb to the cylinder was cracked. That allowed fresh air to be sucked into the cylinder rather than fuel/air mixture. No fuel = no power.

So I would encourage you to keep looking for possible causes of the problem rather than repeatedly performing the same repairs, hoping for improvement.

The Xperts here can probably suggest further things to investigate.

<<Another possible source is the intake seals. I had one last year that that sounded like it was sneezing and the o-ring at the head was leaking air. >>


I notice Star Tech in the previous post suggests that just the kind of issue issue I described be checked out.

 

[Jws123]

Will take a look at it again tomorrow il re set valves and check all seals and intake for cracks and yes both rocker arms move a lot dont think its a worn lobe.

 

[Fish]

Take off the valve cover, and crank the engine while taking a video of it.

 

[Jws123]

Take off the valve cover, and crank the engine while taking a video of it.

Will do also forgot to mention when i got this it had a bent push rod on exhaust replaced it assumed it was due to a backfire or something.

 

[Tinkerer200]

Will do also forgot to mention when i got this it had a bent push rod on exhaust replaced it assumed it was due to a backfire or something.

A bent push rod almost always means a slipped valve guide. Valve guide should not extend more than 1/8 inch above head casting. Otherwise valve keeper hits top of valve guide bending push rod. IF this is the case, B&S says the only fix is a new head. I have a tried and true permanent fix as well as some others sent to me IF you want them, address below, put in proper format and remind me engine model number and what you want.
Walt Conner
wconner5 at frontier dot com

 

[Jws123]

A bent push rod almost always means a slipped valve guide. Valve guide should not extend more than 1/8 inch above head casting. Otherwise valve keeper hits top of valve guide bending push rod. IF this is the case, B&S says the only fix is a new head. I have a tried and true permanent fix as well as some others sent to me IF you want them, address below, put in proper format and remind me engine model number and what you want.
Walt Conner
wconner5 at frontier dot com

Yea i saw that on few other posts when i took it apart that people said valve guide slips was not the case on this one i checked when i replaced head gasket I will get a good vid when i take the valve cover off again

 

[Jws123]

Re adjusted everything today new gaskets still runs like shit pops threw intake However i got the blades today so i decided to just run it i cut the grass for about 2 hours it appears to run steady when under load blades on and moving it cut the grass no problem as soon as the load is gone its back to reeving up and down and pops.