G16A 2000 Yamaha gas cart

[kksi]

I recently took this cart in for service again as the cart was backfiring. Running at full speed it was fine. Coasting and coming to a stop is where the cart would backfire. I was told two things:

1) The governer was adjusted for full speed and because of this there is constant gas being put in the carburetor even when your foot is not on the gas pedal. This over abundance of gas in the carburetor will cause the backfiring.

2) Running this model at high speeds will ruin and eventually burn up the motor.

Can I recive some opinions on these situations ??......thanks for your help !!!

[pistolpete]

how is the air filter? i have a G16 and i run it goverened wide open. never have any problems. try useing fresh 93 octain fuel for a tank or two.

[essness]

I dont like the answer you got with regards to the gov. So, I'll try to give a better one. When you let off the gas the butterfly in the carb should be closing, generally when backfiring occurs it's because that butterfly is not closing. Make sure your accelerator cables are not so tight that the butterfly is not closing.

Now, the second statement regarding running at higher speeds/rpms will eventually burn up your motor is true. Just make sure you are not exceeding about 4000 to 4200 rpms and keep the oil full and clean.

[kksi]

Thanks for your reply and help. Question......even though the engine is now 12+ years old would it be feasible to use a good synthetic oil to help avoid engine breakdown??

[essness]

I use a synthetic in all my carts. My 97 G16 as well.

[junior1954]

Engine backfire on deceleration sounds like a burned exhaust valve or one that is adjusted too tight. Respectfully, engines don't backfire on deceleration because they're getting too much gas. Could be carbon build up on the top of the piston as well. Try Seafoam in the carb. Dan at Plowman's said that unless you do something to unrestricted the air filter, the cart can suck oil through the breather tube at high rev.s. They sell a kit that includes a new high flow air filter (I thinks it's a K&N) and bigger jets for the carb to accommodate the higher rpm's.

As to a G16a engine, it has an over square bore where the piston diameter exceeds the stroke. Over square engines can rev higher and as was noted above 4000rpm shouldn't be a problem-boats, snowmobiles, motorcycles, etc. all run that fast and more. It does have a splash lubrication system (no oil pump), so synthetic (like Mobil One 10-30) is highly recommended-don't put anything thicker than that in as it doesn't "splash" as well. 25mph is about 4000rpm with stock tires and gearing.

[kksi]

Thanks for all the great answers. This forum has been very helpful.

[kksi]

ok I just got my cart back from the shop after the 3rd time for essentially the same problem. The cart would run, die and then not be able to restart. This shop supposedly made the necessary repairs only to have the same problem happen over and over. On the work order they said" last time we will work on this cart and will need a new carb soon". My question is....I know a little about engines but admit Im far from an expert. But these engines are just basic engines and no computer components etc so why are they having so much trouble fixing it? And...how do you know you need a new Carb vs just getting th old one rebuilt??

[golfcartg]

ok I just got my cart back from the shop after the 3rd time for essentially the same problem. The cart would run, die and then not be able to restart. This shop supposedly made the necessary repairs only to have the same problem happen over and over. On the work order they said" last time we will work on this cart and will need a new carb soon". My question is....I know a little about engines but admit Im far from an expert. But these engines are just basic engines and no computer components etc so why are they having so much trouble fixing it? And...how do you know you need a new Carb vs just getting th old one rebuilt??

I get where you're coming from and I totally understand your frustration. Dealing with the same issue over and over can be incredibly annoying, especially when you're not sure why it keeps happening.

Here's the deal: the shop's suggestion about needing a new carburetor is probably on the money. See, when you press the gas pedal, coast and then get that backfire, it's often because the fuel isn't flowing right within the intake. Now, that could be because your current carburetor is all gunked up, and the rubber and gaskets within are no longer sealing properly, when you let off that pedal to coast and get all that back pressure coming off the engine, fuel and air seeps in the the cylinder, and when you press your foot back on the pedal, all that extra fuel ignites. Boom. You get the back fire. If the carburetor was recently replaced and they used an aftermarket carburetor, aftermarket carburetors are not tuned to OEM spec, no matter what they claim, and could also cause this issue.

To sort this out once and for all, I'd recommend getting your hands on an OEM carburetor straight from Yamaha. That way, you know it's tuned specifically for your cart, and it should fit and work like a charm. Make sure to replace all the gaskets and seals around the carburetor too. That'll help keep everything sealed up tight and running smoothly.

About messing with the valve lash – unless you're planning on diving deep into an engine rebuild, I'd steer clear of that. If all else fails, look into adding a spark arrestor or silencer to the tail pipe. Cheers