Two cylinder briggs now a one cylinder

[trkbldr]

Two year old Feriss ZTR with a two cylinder 30 HP Briggs commercial engine. Engine started popping and running rough about a week ago.
So far I have replaced the gas with gas from a different source, replaced both spark plugs, confirmed spark to both plugs, and checked the air gap
on the flywheel. A few days ago I could remove either plug wire and the motor would continue to run. Today when I pulled the left plug wire the
motor immediately died. Pulling the right plug wire has no effect on the motor. I once again confirmed spark to right side. For some reason this cylinder
is not firing. I have a limited knowledge in this area and could use some advice on what the problem could be and how to further diagnose the problem.
My best guess is either a carb problem with no gas going to this cylinder or a valve issue. Hoping it's not a valve issue as that will mean a trip to the dealer.
Any advice will be greatly appreciated.

 

[Baby Grand]

Bent, worn or displaced pushrod or rocker?
Locked up intake valve maybe?
Have you tried checking the valve gap settings, yet?

 

[amaxwell]

I would start with the easy stuff first.Have you replaced the spark plug on the side that is not working. Could be just a grounded out plug.

 

[trkbldr]

Checked valves today. Gap was perfect. All seems to be OK. Nothing stuck or bent. Have already replaced plugs. Swapped mags today and same cylinder still didn't fire.
However, when I removed the air filter and slowly dripped gas into the intake, it would smooth out and sound fine. My limited knowledge tells me that cylinder is not getting fuel.
Sound right?

 

[sdef]

Checked valves today. Gap was perfect. All seems to be OK. Nothing stuck or bent. Have already replaced plugs. Swapped mags today and same cylinder still didn't fire.
However, when I removed the air filter and slowly dripped gas into the intake, it would smooth out and sound fine. My limited knowledge tells me that cylinder is not getting fuel.
Sound right?

Sounds like it to me also, assuming the spark is strong enough and the spark timing is correct. I would assume a single carburetor that feeds both cylinders?Does it have a separate fuel source for each cylinder?

Sounds kinda strange if it does not. Possibly a bad camshaft lobe affecting that one cylinder or a broken piston. However, trickling fuel into the air inlet seems to isolate to a fuel related issue. I would also do a compression check and compare the two cylinders. Inexpensive gauges can be found at auto parts stores.

 

[Walt 2002]

When asking advice on an engine you really should furnish the engine model number so we know what engine we are talking about. Some B&S engines do have separate sections for each cylinder. I can send you a Service Manual IF you like, address below, put in proper format and remind me engine model number and what you want.

Walt Conner
wconner at frontier dot com

 

[trkbldr]

To answer the questions: Single carb fed by one fuel source. The engine is a model 49M977. Walt, I appreciate the offer of the manual. I really only do basic
simple stuff so the manual would most likely go unused. I really don't have time to devote to further tinkering on this mower. This morning I threw in the towel and took it
to the dealer. Hopefully I'll have it back in a couple of weeks. Thanks to everyone for the suggestions and help.

 

[amaxwell]

Can you let us know what they find

 

[trkbldr]

Well it wasn't two weeks, only two days. They cleaned the carb and replaced the fuel filter and it runs like a champ. At a reasonable cost also.
Great dealer giving great service. Joe Hills in Bardstown Ky.