Briggs and Stratton running on one cylinder

[Nosuchluck]

I have a briggs 18.5hp twin horizonal. Getting no compression on one side. Both valves are moving correctly, no blockage in the intake, healthy spark. I pulled the piston, rings aren't stuck. It'll fire up and run on the one cylinder, so I know its getting plenty of gas. Really not sure what's causing it.

 

[bbirder]

I have a briggs 18.5hp twin horizonal. Getting no compression on one side. Both valves are moving correctly, no blockage in the intake, healthy spark. I pulled the piston, rings aren't stuck. It'll fire up and run on the one cylinder, so I know its getting plenty of gas. Really not sure what's causing it.

Check valve adjustment

 

[StarTech]

Engine numbers would be helpful as there both a L-head and an OHV twin engines. Old L heads have the tendency to reduce valve clearance to zero leading to no compression.

It would been wise to have done a non invasive leak down test on the cylinder with no compression prior to tear down as it pointed you in the right direction. It can be foriegn material holding the valve off the seat, broken valve seat, a blown head gasket, or bad rings.

Here I have a Honda GCV160 with no compression with both valves moving the same and correctly gaped. Even the spring heights are the same. But the leak down indicates a 80% leakage rate through the exhaust valve. I probably have a bad valve seat but requires a complete tear down of this particular engine due how the engine designed just to check. It will be my first Honda of this design to go into. It will used as a training exercise so the customer will not get billed for all the time involve for me learning new to me engine design. Things like this usually take me a lot longer as I careful pay attention to the disassembly the first time I do it.

It is sorta like the first time I pulled a Cam Am rear differential it took 4 hours and a week later the same job only took one hour which is what I figured was the needed time as that is what I billed the first customer, writing off the other three hours as training.

Now the Briggs are not that hard to find out but as I said a non invasive test should have been done first.

 

[hlw49]

Engine numbers would be helpful as there both a L-head and an OHV twin engines. Old L heads have the tendency to reduce valve clearance to zero leading to no compression. As StarTech said. If it is a V twin and has a two barrel carb it could be one side of the carb is stopped up. As each barrel feeds one side of the engine.