Hisun Engine Surges

[Demerest]

I bought a used 2017 Coleman with the stock Hisun engine. I got it home and it started right up but it surges up and down at idle. What would be the first thing I should look for?

 

[Minimichael]

I bought a used 2017 Coleman with the stock Hisun engine. I got it home and it started right up but it surges up and down at idle. What would be the first thing I should look for?

The jet's probably clogged or lacquered up so the carb is functioning lean. Post pics of the carb, and thoroughly clean it and the jets. Don't adjust anything else yet.

 

[Demerest]

Would a complete tear-down be necessary or just do the jets with carb cleaner and compressed air?

 

[creia]

Would a complete tear-down be necessary or just do the jets with carb cleaner and compressed air?

"... thoroughly clean it and the jets" (See reply above) = "complete tear-down."
Michael

 

[LIVIT]

Along with a good carb clean. I would dump fuel tank, could have some old fuel, debris etc...

 

[Lizardking]

The first mini bike I bought is a 2016 Coleman with the same engine that started up and ran good but idled bad. I cleaned the idle jet and solved the problem. I still took off the carburetor and completely cleaned it as suggested by others. Flat head screwdriver to pop it off and cleaned using a bread tie wire for the small holes.