Briggs 422707 opposed twin carb

The little throttle shaft dust sponge is in some of those type carb gasket kits. (easily overlooked when it falls on the floor)

When the carb gets old they usually just rot away and no one ever knew they were ever in place.
 
Forest#2 said:
The little throttle shaft dust sponge is in some of those type carb gasket kits. (easily overlooked when it falls on the floor)

When the carb gets old they usually just rot away and no one ever knew they were ever in place.
Click to expand...
c
No screen it was just sitting on top of engine screen for flywheel!
My little rubber gasket worked much better than the Fibre dyst sponge gasket!!
Engine running nice now think its ready to button up cleaning up deck should be cutting soon!
It was a fun project ready to take on another!
Got another opposed twin out of a DOA mower should be a good runner carb cleaned up waiting for some gaskets and gas line!
Thanks Forrest
 
Forest#2 said:
The little throttle shaft dust sponge is in some of those type carb gasket kits. (easily overlooked when it falls on the floor)

When the carb gets old they usually just rot away and no one ever knew they were ever in place
Forest#2 said:
The little throttle shaft dust sponge is in some of those type carb gasket kits. (easily overlooked when it falls on the floor)

When the carb gets old they usually just rot away and no one ever knew they were ever in place.
Click to expand...

Couple more questions
Click to expand...
What spark plugs do you like to run and what rpm settings?
I think low is from 1200-1400
High upto 3400
And what do you think rpms should be when mowing?
Right now I have CHAMPION RJ19LM Plugs
Thanks
 
McTurff said:
What spark plugs do you like to run and what rpm settings?
I think low is from 1200-1400
High upto 3400
And what do you think rpms should be when mowing?
Right now I have CHAMPION RJ19LM Plugs
Thanks
Click to expand...
That is the same plugs that I use because they are readily available. I really do not like CHAMPION plugs but they last a long time in the opposed twins. If you ever run into a opposed twin that will not start up when the engine is hot and you install new plugs and it's ok for awhile and does same thing again after it's run awhile, it;s a weak magneto. I've tried the $80 Napa magnetos and had them fail. I just use the $20 clone magneto's from Amazon or ebay with good results and keep a spare handy. (do not install a magneto upside down. Seen one engine that a guy had pulled the heads thinking bad intake valves, it had spark but would not start. I put it back together and replaced the magneto and it fired right up. The electronics in the opposed twin magneto does some weird things.
You are close enough on the rpms. The specs are in the service manual and the high rpm is easily adjustable on a big screw on the throttle plate. Sometimes that screw over several hours will vibrate to a lower rpm and green or blue thread lock will secure such. (FIRST make sure the STATIC governor is correct if you have issues with high rpms) You want to keep the engine speed at high rpms when mowing, max air across the engine. Install a pre-foam air filter and your main air filter will last longer. (and keep the fins clean. I use a leaf blower or air compressor and clean the engine often if mowing in dirt or lots of dead grass. Clogged fins will result in valve seats coming out.
If you ever have a valve seat pop out contact me and I have a easy permanent fix for such.
Better than trying to do the staking.

Another thing you will notice on the opposed twins that is mis-leading when troubleshooting is when one is cranking fast and not starting (due to ignition issues) and it's getting gas you WILL SEE the carb spitting gas up out of the carb throat making you think a intake valve is not seating. I've seen guys pull the heads looking for bad valves due to seeing such.
It's normal. If you want to see such just kill the ignition and look into the carb throat when it's cranking. You will be surprised if you have never noticed such before. If you give it a squirt of gas as a prime it will spit some back up out of the carb throat when it's cranking fast. (It's the intake valves momentarily doing the compression release)
 
Last edited:
Forest#2 said:
That is the same plugs that I use because they are readily available. I really do not like CHAMPION plugs but they last a long time in the opposed twins. If you ever run into a opposed twin that will not start up when the engine is hot and you install new plugs and it's ok for awhile and does same thing again after it's run awhile, it;s a weak magneto.
You are close enough on the rpms. The specs are in the service manual and the high rpm is easily adjustable on a big screw on the throttle plate. Sometimes that screw over several hours will vibrate to a lower rpm and green or blue thread lock will secure such. (FIRST make sure the STATIC governor is correct if you have issues with high rpms) You want to keep the engine speed at high rpms when mowing, max air across the engine. Install a pre-foam air filter and your main air filter will last longer. (and keep the fins clean. I use a leaf blower or air compressor and clean the engine often if mowing in dirt or lots of dead grass. Clogged fins will result in valve seats coming out.
If you ever have a valve seat pop out contact me and I have a easy permanent fix for such.
Better than trying to do the staking.

Another thing you will notice on the opposed twins that is mis-leading when troubleshooting is when one is cranking fast and not starting (due to ignition issues) and it's getting gas you WILL SEE the carb spitting gas up out of the carb throat making you think a intake valve is not seating. I've seen guys pull the heads looking for bad valves due to seeing such.
It's normal. If you want to see such just kill the ignition and look into the carb throat when it's cranking. You will be surprised if you have never noticed such before. If you give it a squirt of gas as a prime it will spit some back up out of the carb throat when it's cranking fast. (It's the intake valves momentarily doing the compression release)
Click to expand...
Forest#2 said:
That is the same plugs that I use because they are readily available. I really do not like CHAMPION plugs but they last a long time in the opposed twins. If you ever run into a opposed twin that will not start up when the engine is hot and you install new plugs and it's ok for awhile and does same thing again after it's run awhile, it;s a weak magneto.
You are close enough on the rpms. The specs are in the service manual and the high rpm is easily adjustable on a big screw on the throttle plate. Sometimes that screw over several hours will vibrate to a lower rpm and green or blue thread lock will secure such. (FIRST make sure the STATIC governor is correct if you have issues with high rpms) You want to keep the engine speed at high rpms when mowing, max air across the engine. Install a pre-foam air filter and your main air filter will last longer. (and keep the fins clean. I use a leaf blower or air compressor and clean the engine often if mowing in dirt or lots of dead grass. Clogged fins will result in valve seats coming out.
If you ever have a valve seat pop out contact me and I have a easy permanent fix for such.
Better than trying to do the staking.

Another thing you will notice on the opposed twins that is mis-leading when troubleshooting is when one is cranking fast and not starting (due to ignition issues) and it's getting gas you WILL SEE the carb spitting gas up out of the carb throat making you think a intake valve is not seating. I've seen guys pull the heads looking for bad valves due to seeing such.
It's normal. If you want to see such just kill the ignition and look into the carb throat when it's cranking. You will be surprised if you have never noticed such before. If you give it a squirt of gas as a prime it will spit some back up out of the carb throat when it's cranking fast. (It's the intake valves momentarily doing the compression release)
Click to expand...
Thanks
Cleaned up deck and waiting for a belt and can't wait to cut some grass!
 
McTurff said:
Thanks
Cleaned up deck and waiting for a belt and can't wait to cut some grass!
Click to expand...
So its finally finished this mower tested me In almost every way I learned alot and was challenged throughout the entire process!
Thank You to everyone that helped with your knowledge 🙏
Here are a couple pics
Think I will name it McTurff
 

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