6.75 Briggs Auto choke

[Sawfxr]

Rivets,
It's a brand new carb right out of the box. It was only on the motor for less than a minute before it started surging. I didn't bother pulling the bowl because of the fact it was a new B&S carb and not a used one. I experimented a bit this morning by putting more tension on the governor spring and raising the running RPM's a little. The surging seemed less and was not as bad with about 150-200 more RPM's on the handheld tach.
E.

 

[Rivets]

Ok I guess I can't help. Good luck.

 

[pugaltitude]

:biggrin:

Rivets,
It's a brand new carb right out of the box. It was only on the motor for less than a minute before it started surging. I didn't bother pulling the bowl because of the fact it was a new B&S carb and not a used one. I experimented a bit this morning by putting more tension on the governor spring and raising the running RPM's a little. The surging seemed less and was not as bad with about 150-200 more RPM's on the handheld tach.
E.

Sounds as though its sucking air somewhere. Check the oring and intake manifold.
Also the spring for the ready start carb is different to the primer.
The primer spring is stronger.
Did you fit the primer as well or just the carb?

 

[JosephP.]

Am a newbie to site and am having the exact same issues with warm starts on my 675series ready start mower.I have had this issue since 2010 when I purchased it.When I change bags I have to wait. I keep my gas can,gas on mower,carb impeccable.Run my fuel through a 15 micron sock,drain my mower of gas,take float bowl down,etc.etc.etc. Point is I have avoided all the issues of starting my mower that I could think of thinking it was something I may have been doing wrong or missing. Then I started looking up online and finding that I am not alone.I have had my thermostat arm exposed 1/2 a dozen times evaluating and tweaking the adjusting piece on the choke itself.Replaced it,re built the carb and still,,,,starts perfect 1st time cold,then once hot (ZIPPO) nothing. Is there a air filter box and carb that I can go back to,"old school"with. I consider myself to be pretty hands on being as how I run my chainsaws,back pack blowers and have a pretty good basic concept of this stuff but this auto choke just ain't working. Is there a up to date diagnostic check for these systems or is a new carb my best bet? Even a way to manually work the arm once the engine is hot ?????

 

[tspikewell]

Am a newbie to site and am having the exact same issues with warm starts on my 675series ready start mower.I have had this issue since 2010 when I purchased it.When I change bags I have to wait. I keep my gas can,gas on mower,carb impeccable.Run my fuel through a 15 micron sock,drain my mower of gas,take float bowl down,etc.etc.etc. Point is I have avoided all the issues of starting my mower that I could think of thinking it was something I may have been doing wrong or missing. Then I started looking up online and finding that I am not alone.I have had my thermostat arm exposed 1/2 a dozen times evaluating and tweaking the adjusting piece on the choke itself.Replaced it,re built the carb and still,,,,starts perfect 1st time cold,then once hot (ZIPPO) nothing. Is there a air filter box and carb that I can go back to,"old school"with. I consider myself to be pretty hands on being as how I run my chainsaws,back pack blowers and have a pretty good basic concept of this stuff but this auto choke just ain't working. Is there a up to date diagnostic check for these systems or is a new carb my best bet? Even a way to manually work the arm once the engine is hot ?????

I have had luck taking off the air filter and using a screwdriver or other implement to hold the automatic choke in the open position and then starting the mower.

If the choke is in the shut position it will not receive enough air to run.

Then put air filter housing back on...and continue mowing...