Loping engine

J

jyl23

Forum Newbie
I have a fairly new DR Trimmer with a Briggs ex675 motor. I didn't empty the gas over winter. The nit wouldn't start. I bought a new carburetor and installed it. The mower started right up but it doesn't run smooth, it lopes. What is wrong?
 
Loping or throttle surging is normally caused by a dirty carb that has idle passage in the carb clogged. If you engage the trimmer head does the loping go away or no different
 
If not a Briggs carb the aftermarket carb could be suspect. Also an intake air leak between the carb and were the intake pipe connects to the engine block could cause lean issue. And third an issue with the governor. If you hold the governor steady to stop the surging how does the engine sound. Smooth running or running rough.
 
I will look at these things tomorrow, thanks. Is there something besides spraying the carburetor with cleaner can I do to the original carburetor?
 
jyl23 said:
I will look at these things tomorrow, thanks. Is there something besides spraying the carburetor with cleaner can I do to the original carburetor?
Click to expand...
With a new aftermarket carburetor, and the engine is hunting and surging, it is running lean (not enough fuel). The air/fuel mixture ratio is not right. Best thing you can do in this case is completely clean the original OEM carburetor and reinstall.
 
Tiger Small Engine said:
With a new aftermarket carburetor, and the engine is hunting and surging, it is running lean (not enough fuel). The air/fuel mixture ratio is not right. Best thing you can do in this case is completely clean the original OEM carburetor and reinstall.
Click to expand...
And just to add to Tiger if it is the carb with the metal fuel bowl, don't figure the bowl nut because that is were the main carb jet is located.
 
I tried to clean the original carb., the unit still wouldn't fire. I went ahead and sent the aftermarket one back and ordered a good one. Thanks, you guys for all of your help.
 
Do you have good fuel flow AT the carb inlet?

How much trash is in the fuel tank?

Fuel tank cap vent venting?
 
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