300E Series engine surging

H

hotrodkev

Forum Newbie
Joined
Jul 15, 2018
Threads
1
Messages
2
New user, first time poster. So, hello everyone and thank you for any help you might be able to throw my way!

I received a Yard Machines 20" push mower with the 300E series Briggs & Stratton engine that wouldn't start. I went over the obvious first. Fuel, oil, air filter, and spark plug. All looked well, so I gave the ol plastic carburetor a thorough cleaning. Primed the engine and it started right up, then almost immediately started surging. I went ahead and removed the carburetor and cleaned it once more. Same outcome.

I then:

Removed the gas tank and fuel line, flushed and cleaned. SAME OUTCOME.
Installed a new spark plug. SAME OUTCOME.
Removed the coil and scuffed the flywheel and coil to ensure they were nice and clean. SAME OUTCOME.
Swapped with a different carburetor. SAME OUTCOME.
Swapped the coil. SAME OUTCOME.

I'm at my wits end with this one and just cannot seem to figure it out. I need help.
 
B

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,700
hotrodkev said:
New user, first time poster. So, hello everyone and thank you for any help you might be able to throw my way!

I received a Yard Machines 20" push mower with the 300E series Briggs & Stratton engine that wouldn't start. I went over the obvious first. Fuel, oil, air filter, and spark plug. All looked well, so I gave the ol plastic carburetor a thorough cleaning. Primed the engine and it started right up, then almost immediately started surging. I went ahead and removed the carburetor and cleaned it once more. Same outcome.

I then:

Removed the gas tank and fuel line, flushed and cleaned. SAME OUTCOME. Always worth doing
Installed a new spark plug. SAME OUTCOME. Again worthwhile
Removed the coil and scuffed the flywheel and coil to ensure they were nice and clean. SAME OUTCOME. Total waste of time polishing the coil unless your are an idiot on U-Tube trying to sound intelligent. But cleaning the mounting posts for a good ground is
Swapped with a different carburetor. SAME OUTCOME. Points to something else
Swapped the coil. SAME OUTCOME. Surging has nothing to do with the sparking so waste of time

I'm at my wits end with this one and just cannot seem to figure it out. I need help.
Click to expand...

Surging is always due to lack of sufficient fuel to maintain high speed running.
So either you still have a fuel blockage in the system or you have an air leak between the carb venturi and the inlet valve.
Running under the coil that you polished then replaced is a manifold tube, usually plastic and usually cracked or loose.
Do not over tighten the 1/8" bolts, replace the gasket is the bolts or tube is loose.
Replace the tube is if is cracked or warped.
Replace the O ring seal just to be on the safe side.

300e means nothing what is needed to get proper information & help in the model , type & code.
If this is a Chinese Briggs then it will be on a sticker and also electroetched in the block behind the carb.
IF it is a USA made one the numbers will be on the heat shield above the muffler
 
Last edited:
Boudreaux In Eunice La.

Boudreaux In Eunice La.

Lawn Addict
Joined
Jul 22, 2017
Threads
21
Messages
2,154
Hot Rod you have the newer style plastic carb on your mower..... I am very familiar with those ....... I will post a link for you to a video........... Hold a sec...........
 
Boudreaux In Eunice La.

Boudreaux In Eunice La.

Lawn Addict
Joined
Jul 22, 2017
Threads
21
Messages
2,154
Ok here's the link to the vid...... If you don't like a lil comedy skit then skip to the 8:00 minute mark and see the problem you have.....

It's a lot easier for me to post a video than trying too type all this stuff....

https://youtu.be/_5PBMOZLclQ

Let us know Mon Ami ~!~!
 
H

hotrodkev

Forum Newbie
Joined
Jul 15, 2018
Threads
1
Messages
2
Boudreaux In Eunice La.

YOU ARE THE MAN!! Apparently the little ball in the top of the cartridge was the issue ( I didn't realize this could be removed). I pushed that out and didn't see any debris but went ahead and re-cleaned everything once more. Fired right up with no surging.

Thank you again! You have a new subscriber to your channel. :thumbsup:
 
Boudreaux In Eunice La.

Boudreaux In Eunice La.

Lawn Addict
Joined
Jul 22, 2017
Threads
21
Messages
2,154
Thanks for the reply Hot Rod...... But that's not my channel.... My channel is Boo LuQuette. I do have small engine repair/how to vids and gardening.... Plus other cooking and at my radio show on Thursday nights at KBON 101.1 FM.

Check em out when you get a chance..........

Plus Tard Mon Ami ~!~!
 
You must log in or register to reply here.

Footer Links 1

Top