Governer Bypass Complete...Now backfiring

[Mike D]

Alright guys, I could use a little insight. First off, I got my G16 cart rebuilt, rear seat on, body back on, lights installed...finally. I did the sticky post of drilling out the governer to bypass it. Now I've picked up the occasional backfire while deccelerating. I'm not sure what may be causing the problem, and before I do anything I was looking for some advice. I thought this was addressed on another thread, and if it was I'm sorry. I couldn't find it.

Next thing is, more power/speed increase. I've noticed that two site sponsers offer some high perf parts for the G16. I looked at the Plowman's site and CPP. Their parts/kits seem to both have their advantages, but I'm not sure which one is better bang for the buck. I don't climb many hills or do much off roading here in south florida, but more low end with a small increase in top end would'nt be bad for neighborhood bragging rights.Any advice you guys have is greatly appreciated.

[Tonka329]

Well Mike, I think you may be "pushing" the RPM's a little high. I have noticed that 4 strokes seem to backfire on high RPM. It may something as simple as timing also I don't have many hills around my area either... I will be leaning to the Dixie Power Kit from CPP. I will be putting a 7" lift and 22" tires. Torgue is always helpful with that!

[boltz]

It may be unrelated, i would look at the air box and make sure it is all tight also look and make sure your spark plug is tight and last loomand make sure you don't have an exhaust leak. I have a g16 and have no gov on it period and have no problems. Good luck

[rib33024]

Check the butterfly in the carb, sounds like It's NOT shutting all the way, you might need to adjust the cable , this will cause back fire--

[Mike D]

I did notice that I have what sounds similar to a car type of exhaust leak upon acceleration. When I get to a certain rpm, the sound stops. Kind of like when the engine is under load, up until a cruising speed. I'm hoping that it isn't a rod knock, but I know with cars the knock continues through the power band of the engine. Anyone had anything similar to this as well? Can anyone tell me how to check the timing on this motor? I need to get a manual... just been dragging my feet. I will also be looking into the suggestions that everyone posted. Thanks fellas

[sabercat]

rib is prob right check your butterfly is closing all the way.

[BigBlockMan]

A closer look is needed. A exhaust leak will cause a backfire, Also as mentioned butterfly not closing, and also a engine with a little extra carbon on the piston or head will also cause a backfire.

[Mike D]

The backfiring usually happens when I've slowed down considerably from my cruising speed, like nearing a stop. I don't know if that helps anyone for possible diagnosis. How would I go about looking for carbon buildup? Just pull the head, or is there anything else. Also is there something I can add to the fuel or motor to break up any carbon without a tear down. That may cause damage to the valves or seals, I'm not sure. I also know that the old air cooled VW motors would backfire from valves not adjusted. Do you guys think that's possible?

[sho305]

Richen the idle jet .25 turn and see what it does. Make sure you are not turning the ignition in/off with the pedal and throttle is open where it turns the engine on/off. If it is the car will take off when it starts. Set valves .004 each, make sure you seal the cover if can leak and fill the fins with oil. You can try running some Sea Foam in it, the stuff works great on outboards. Exhaust leak like they said, check that. If the cart has a lot of time on it, not a bad idea to pop the head off and lap the valves, its not that hard to do or have done. Lot of small engines could use that and you will find out how good the valves are.

[Mike D]

Thanks sho and everybody else for the input. I'm going to try all of these ideas in the next few days. My jobs are real heavy with work this week, so I'm going to mess with the cart when I can. I'll update when I try some of these things. Thanks again