MTD Briggs & Stratton lawn mower surging help

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Ant...

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Hello all
Have this little MTD Briggs & Stratton lawn mower that I'm trying to get running right. the problem that I'm having is I can't get it to stop surging. I've been through the carburetor Twice and still having the same issue. I've cleaned up the coil contacts regaped it. Could this still be in the carburetor?
Here is a link to a video of the mower running

https://youtu.be/K2Kuuq78U0Q
 
L

Luffydog

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I would say is your problem is within the carb. Can you hold the governor shaft and smooth it out. Trying cleaning it again sometimes hard to get all the little passages clean. Then if that didn’t do it I would replace
 
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Rivets

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When you cleaned the carb did you replace the float needle and seat? At the same time you must adjust the float level so it is parallel with the carb body.
 
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Ant...

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Rivets said:
When you cleaned the carb did you replace the float needle and seat? At the same time you must adjust the float level so it is parallel with the carb body.
Click to expand...
I didn't change the needle and seat.
Just so everyone knows this is the plastic carburetor that I'm workin on with this mower. I pulled the white cartridge out, took it all apart cleaned it out. Don't think I left anything behind. I'll pull it one more time.
 
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bertsmobile1

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Ant... said:
I didn't change the needle and seat.
Just so everyone knows this is the plastic carburetor that I'm workin on with this mower. I pulled the white cartridge out, took it all apart cleaned it out. Don't think I left anything behind. I'll pull it one more time.
Click to expand...

Is the main jet still in the bottom of the long tube ?
Just about every time I have a customer come in with one they have cleaned , the main jet is missing.
heaven knows I have sent some into low earth orbit by hitting the jet holder with the wrong compressor supply while working in brain dead mode.

Did you replace the complex plastic seal and if so was it the correct one ?
One has the O ring that seals the float tube as a stand alone part while the latter model has the O ring as part of the seal.
Also the cheap imported kits for these carbs contain the correct parts for the Chinese copy , not the USA made version, that is assuming it is a good set & not one that was rejected because the parts were wrong or defective.
There are 2 different lengths of needle for these carbs and yet a shorter one for the Chinese copy.
 
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Ant...

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bertsmobile1 said:
Is the main jet still in the bottom of the long tube ?
Just about every time I have a customer come in with one they have cleaned , the main jet is missing.
heaven knows I have sent some into low earth orbit by hitting the jet holder with the wrong compressor supply while working in brain dead mode.

Did you replace the complex plastic seal and if so was it the correct one ?
One has the O ring that seals the float tube as a stand alone part while the latter model has the O ring as part of the seal.
Also the cheap imported kits for these carbs contain the correct parts for the Chinese copy , not the USA made version, that is assuming it is a good set & not one that was rejected because the parts were wrong or defective.
There are 2 different lengths of needle for these carbs and yet a shorter one for the Chinese copy.
Click to expand...


I think I may have found the problem. I just got another one of these plastic carburetors on a different mower. I will post pictures shortly. if you look down the throat of both carburetors the one that is surging is missing either a plug or a jet on the left side in the throat of the carburetor.
 

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A

Ant...

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Just an update.
The problem is definitely the carburetor. I swapped out carbs with one that I just got in on another Mower.. mower runs perfect with it. If you look at the two pictures of the carburetor the one is missing either a jet or a plug in the left side of the throat of the carburetor
 
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bertsmobile1

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Right for the wrong reasons.
Please disregard my previous post I was thinking ( or not thinking as the case may be ) of a different carb so it is tosh as far as this problem is concerned.
 
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