Briggs and Stratton auto chock plastic carburators

[WilliamBeeth]

I am new to this site and forum as of today and a rookie so please bare with me.

I have a craftsman self push lawn mower with a briggs and stratton Platinum series 7.25 163cc engine model #104M02-0008. It has the new platinum auto chock carburator thats supposed to be guaranteed to start on the first pull every time. Wishful thinking.
I had to clean the carburator with carb clean now when it starts it putters and blows grey/ whiteish smoke.

Anyone know how to increase the idle speed on that carburator and engine.

Thank you in advance for any assistance its appreciated. Also a diagram showing the correct carb linkage would be so helpful.

William Beeth
Phoenix, Arizona

 

[FordBroncoVWJeta]

How long ago did you buy it? I just bought a new mower last week with a B&S motor and its warrantied for two years. They would probably throw a new carb on it and call it a day.

 

[Fawteen]

It's an auto "choke".
Make sure the arm is actually pulling the butterfly closed when you're starting it. I have a Kohler on a mower and if it doesn't start the first pull I have to just reach down and give the lever a pull to close the choke. Then it fires right up.

Beyond that there isn't much to do on these small carbs, especially if it's fairly new.

 

[MasterSolenoid]

Originally Posted by Fawteen
It's an auto "choke".
Make sure the arm is actually pulling the butterfly closed when you're starting it I have a Kohler on a mower and if it doesn't start the first pull I have to just reach down and give the lever a pull to close the choke. Then it fires right up.

Beyond that there isn't much to do on these small carbs, especially if it's fairly new.

YES. Check that the butterfly is 'closed' when starting.
I always cleaned my mower every Fall and must have LOST the very small spring that closes the butterfly.
Once I realized it and bought a replacement, my Mower (B&S bought 2011) is back to starting on the 1st pull.

To check 'auto' choke lever, remove any engine covers so you can see what your dealing with.

If you need to replace the Carb, here is what I did.
https://www.bobistheoilguy.com/foru...e-in-china-review-lawn-mower#Post5087017

 

[RyanY]

I had one of those plastic auto choke carbs on a B&S a few years ago. Could never get it cleaned well and finally just replaced it.

 

[mk378]

White / blue smoke means you're burning oil, likely from tilting the engine and having some oil spill into the intake system. This should resolve itself. Over-choking or other fuel rich condition causes black smoke.

The choke system is typically controlled by a thermostat near the exhaust. It pulls on a rod to open the choke after a short warm up.

 

[benjayman227]

Not sure why you are interested in the idle speed, but it's likely not adjustable. The newer carbs have fixed-position everything: main jet, idle jet, idle speed, governed speed (unless you start mangling the linkages/springs).

I'll also toss out the usual recommendations of fresh, ethanol-free (if available) gas, stabilizer, drain the tank every year, etc.

 

[WilliamBeeth]

Thank you benjayman227, thank you for your reply. I know the chock spring can be shortened uping the rpms but then I risk over revving the engine and ruining the engine. I am awaiting a reply from briggs and stratten. I will let you know how it eventually gets resolved if your interested.

It sounds like I might be buying another new or rebuilt card on ebay. Not sure yet.

 

[bubbatime]

These carbs are less than $20 brand new. You dont clean a carburetor that cost less than $20. You buy a new one, slap it on, and then it runs like new again.

Look for a bendable tab that a spring hooks to. Bend the tab to increase or decrease the engine RPM.

Check the oil level. If its over full, the carb needle and seat has leaked gas into the oil. And it will smoke like crazy.

 

[mk378]

That's the governor spring. The CHOKE system has nothing to do with rpm.

What exactly is the problem this mower has or you perceive it to have?