Back Fire While Coasting

[lbzya1]

Has anyone had a problem with their G-16 back firing while coasting down hills?

I have a 2000 stock G-16, while driving down our driveway we have to coast towards the end 9 times out of 10 it will back fire. What is the cause of this and is it damaging the motor when this happens?

Any suggestions would be great.

Jeff

[Mike Mac]

A number of things could be the culprit. Throttle not adjusted correctly, air filter assembly not sealed correctly, or exhaust gasket leaking, are some, but maybe not all the causes of a backfire.

[G1-G9]

on our G16 it only back fires when you leave your foot on the pedal. if we dont take our foot completly off from it the thing will back fire every time.

[stuff4mason]

Yea, I fought this problem for the last year. These guys above are right. I learned to go very slow down hills. A little brake pressure at the same time a little gas while going down hills, and you can avoid the backfire.

[lbzya1]

I think G1-G9 is right. I may have had my foot on the pedal while coasting. I will try gas and brake at the same time or maybe just let it coast without my foot on the gas. Thanks for all your help.

Jeff

[sho305]

There are two ways you can try to get rid of it, assuming it does this when you hit the pedal again since nothing should be powered with no pedal. You can set the throttle up so when it starts it idles just faster than the starter which is quite slow so as not to make the cart go. Fiddle with the idle mixture and get it a little on the rich side, that would be open more than it needs. Do they have idle mix? I forget many new engines they are getting rid of them and you have to enlarge the jet.

The second way to try is set the carb so it shuts all the way with no pedal, so it can't idle or get any air when you coast. Some say this works, others say idle works. Sometimes they backfire due to the idle being lean and other times it is just a hot muffler with gas in it. Some carbs will get strange when they close all the way, due to no airflow it messes up the fuel flow.

The above assumes you have a sealed airbox and all that. Some carts someone messed with and adjusted the carb cable too tight so the throttle is on when it starts. That can cause it and you can tell because the cart will not go slow, it is either off or 5mph/etc and no 1mph is possible. Loosen the throttle cable so it does not take off when the engine turns over to start.

[Doug c]

When I have several people on the cart and go up a big hill, it back fires when I let off the gas completely on the way down the other side of the big hill.

[crash12888]

The main issue is because the carb butterfly is adjusted or being held partially open. You need to adjust the throttle linkage and/or back off the stop screw so the butterfly is 100% closed.
When coasting down the hill the engine is still turning and if the throttle is open even a little bit it will still draw fuel. So while the spark is grounded by having your foot off of the pedal when you get to the bottom and push the pedal you fire all the gas that has been sucked into the cylinder and exhaust.
Get the carb to close and it will go away.

[Doug c]

I have noticed also that it backfires when we stop, engine no longer running, within a few seconds after cruising around the neighborhood. It only backfires when we have been driving it around for awhile.