03 CarryAll diesels then runs backwards

[GHale]

Symptom: I Let off the gas, engine appears that it is stopping but then knocks 1 time, diesels and rotates backwards so much so that cart starts backing up until engine shuts down in a second or two of dieseling. Any ideas why when I remove foot from gas pedal why it won't stop running?

Thanks for your input if you've seen this before.

Garry

[Volt_Ampere]

After run is usually caused by carbon buildup.

[GHale]

Suggestions on which way to head for carbon buildup? SeaFoam or other additive like auto carbon issues?

Thanks

[Volt_Ampere]

Remove head and remove carbon.

[lockman1]

Yeah... I agree with V_A!

BUT... you could first try a 1/2 oz of SeaFoam in the spark plug opening,
Remove the spark plug, pour in about a 1/2 shot of SeaFoam, and reinstall the spark plug, (without the plug wire attached),
Turn the engine over for about 10 to 15 seconds, then, let it sit for an hour or 2.
With the cart in maintenance mode, reattach the plug wire, and in an open space... start the engine!
Once it starts, it'll smoke like h*ll!, run it at part throttle until the smoke dissipates, and see if the dieseling stops!
If not... then pull the head to clean the carbon deposits!

WTH... it's worth a shot! (or a 1/2 a shot!)

[GHale]

I will try the shot in the plug thing and let you know.

FYI - When I pulled the air hose off coming from the air filter, I found the bottom of the intake to the carb wet with gas. I tightened the spring attached to the throttle hoping to shut the fuel supply off. Actually makes it diesel then run backwards worse. A few times when dieseling for 10 seconds or longer I turned the ignition key to off and it continued to diesel then run backwards. One time it ran for maybe 2-3 seconds backward and the cart backed up 8+ feet.

Is it safe to assume that by turning the key off that regardless of possible micro switch malfunction, there was no electricity going to the plug?

I'm going to prove this theory further by having the dump bed up before shutting off and then snatching the plug wire off while dieseling. If it continues to run then, it has to be carbon heat buildup causing preignition.

Where's the least expensive place to buy a head gasket for the FE 350? My cart is a RG and was built in 03 34th week so its closer to an 04.

Thanks

[GHale]

"Problem solved" - carb throttle screw needed backing out a few turns as the throttle was not closing all the way. Also - ran Blaster "Lawn mower Tune up", through it by running engine and spraying into air intake. Fantastic stuff and I would recommend trying that before rebuilding or buying carb.

I bought extra cans as I have a sick mower and generator that this may help on as well. I found it at "ACE" Hardware but may be in big box stores as well or on-line

Thanks for your assists.