Surging Engine on 6.5HP Craftsman Push Mower

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YBRmuggsLP21

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• Jun 18, 2018 / Surging Engine on 6.5HP Craftsman Push Mower

• #1

Hey all,

I've been trying to get my push mower running properly, and have been unsuccessful thus far. Basically, if I run the throttle anywhere between (roughly) half to full, it the engine will start surging. It will sometimes stop when just idling, but then as soon as I actually start cutting, it will do it again. Seems to run okay under half throttle with maybe a little popping here and there.

So far I have cleaned and rebuilt the carburetor, replaced the air filter and spark plug, and replaced the fuel cap. (It also has fresh gas and oil). What else should I be looking into?


Thanks!
Nick

 

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Rivets

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• Jun 18, 2018 / Surging Engine on 6.5HP Craftsman Push Mower

• #2

Surging is normally a sign of a lean mixture. When you rebuilt the carb did you set the float level? I like to set them a bit rich, meaning the side of the float opposite the float pin, should be slightly lower when the carb is tipped upside down.

 

Boudreaux In Eunice La.

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• Jun 18, 2018 / Surging Engine on 6.5HP Craftsman Push Mower

• #3

Did you change the red needle seat in the carb ???? Those swell up and the float cannot set right ......

Did you clean the main jet ?? That would be the bowl nut itself.... It has a small hole on top of it and has 2 holes on the side of it.... It those holes are not cleaned well and then sprayed with carb cleaner it will cause your issue.....

Let us know Mon Ami ~!~!

 

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YBRmuggsLP21

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• Jun 18, 2018 / Surging Engine on 6.5HP Craftsman Push Mower

• #4

Aloha,

I didn't make any adjustments to the float, (didnt know I could quite honestly, didnt seem like there was anything to adjust).

Needle seat and jet (bowl nut) were both replaced.

Thanks,
Nick

 

Boudreaux In Eunice La.

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• Jun 18, 2018 / Surging Engine on 6.5HP Craftsman Push Mower

• #5

YBRmuggsLP21 said:

Aloha,

I didn't make any adjustments to the float, (didnt know I could quite honestly, didnt seem like there was anything to adjust).

Needle seat and jet (bowl nut) were both replaced.

Thanks,
Nick

Click to expand...

Fuel line can be going bad on it... You have only one line on that one.... Clogged nipple on the tank.... Carb not cleaned well as in dipped in carb acid over night and then sprayed out well ..... Groove side of seat facing needle instead of down toward the carb body....

Those are the only things left to check.... Unless for some reason your governor needs to be reset..... Or a new gov spring ........

Let us Know Mon Ami ~!~!

 

Boudreaux In Eunice La.

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• Jun 18, 2018 / Surging Engine on 6.5HP Craftsman Push Mower

• #6

If the above doesn't do the trick then you might need a valve lap.... How old is the engine ????