B&S V-Twin Backfires Under Load

Bat57

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Oct 3, 2019
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I have a B&S 26Hp V-Twin (44R677 0016 G1) that I completely rebuilt with new seals and gaskets, soaked and cleaned out all passages. Engine idles and runs at operating speed fine but when I engage the mower deck it starts to backfire some. Any ideas what would cause this? Going to try a higher octane fuel to see if that helps.
 

bertsmobile1

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Out the carb or out the exhaust
Black smoke or white smoke.
The jets on those carbs have a bad habit of falling out unless the O rings get replaced so they will run fine till th throttle is opened up & the engine starts to suck fuel through the main jet.
 

Bat57

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out the carb I believe No smoke. the jets on the v-twin actually sit in the top of the tube and insert down into a grove from the top. Not like the Nikki carbs on the single cylinder engines. I replaced both o-rings on the 2 jets and replaced all the seals and gaskets with new ones. I am going to take it apart again and recheck everything.
 
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