Lawnmower cuts out on fast idle + runs rough

Jim Parker

• 1041 Answers
• Posted on Jun 21, 2009

SOURCE: brand new honda lawnmower starts and runs fine then backfires

There should be 1 or 2 screws on the carb. You will probably have to remove the air breather to get to the screw(s). I've been seeing a lot of these types of questions, new equipment not running properly. Factory settings were not set properly.

When you find the screw(s), screw in a clockwise direction until it stops; DON'T SCREW DOWN TIGHT, JUST UNTIL IT STOPS. Then unscrew counter clockwise 1 1/4 turns. Try starting.

Continue this process, 1/4 turn at a time up to 2 1/2 full turns. If you forget where you are at on the turning process, start over by screwing back down. Then pick up process where you left off.

If you need further assistance, just let me know.

Jim

SOURCE: starts but when chock goes off stops running

OK take and check this. A lot of the honda engines,especially push mowers,tillers and pressure washers,they put a type of coating inside the gas tank. The bad thing about this type of coating is it has a tendency to peal and wash into the carb. I would look inside the tank to see if there is any debris. I would also clamp off the fuel line and take out the bolt that holds the fuel bowl on and catch the fuel that drains out in a clean tray. If it looks dirty,pull the carb and clean it,it should fix it.

SOURCE: Running problems with Mountfield HP454 petrol lawnmower

First thing to check is the air filter. It may be plugged.

SOURCE: i have a honda o

I have the GVC160 motor....same problems....just found this info (see link),...and it turned out that Honda used a NGK spark plug that was defective,....I couldn't believe that is all it was...after changing the carb (new),...adjusting valves....etc.. I just went down and bought a new spark plug.....and it runs great!!
----
BEFORE go thru all of the advice and look at most other Honda web info.....go and buy a brand new spark plug and start with that! It appears Honda used a NGK spark plug in the past that fails after some time....giving the syptoms of problems with the carb, sticky valve, etc. Do not try to clean and use the old spark plug!! Check this out....it was the answer I was looking for after hours of work, reading, and talking to Honda dealers - http://forum.doityourself.com/outdoor-power-equipment-small-engines/261743-honda-lawnmower-starting-then-cutting-out.html

SOURCE: I have a MTD Honda Lawnmower that is having idling

Generally this indicates a "lean" condition in the carburetor and there are no adjustments. Depending on your abilities, the best fix is to remove the carburetor and clean all the metering passages/jets. In some cases you are better off just replacing the carburetor. I have seen some Honda carbs. as low as $15-$20. Hope this helps to some degree.