G2 Engine Issue

[chrisnin]

Hi all,

Just looking for some help. I have a G2 that is acting up. When you press the gas pedal all the way down, the engine loses power. If you keep the pedal depressed 1/2 way, it will run fine at half throttle, but as soon as you go past 1/2 way, it starts to cut out. I checked the air filter box, and it seems to be sealing tight. I did notice that my air filter and foam filter appear to be saturated with some type of oil/gas goo. Oily residue was also on the bottom of the air filter box. Spark plug was also a bit fouled up. Washed the filters in warm water with a mild detergent, dried them, and also changed the plug. Still does the exact same thing! Air filter is still a bit oily, even after washing. I see that it also has an in-tank fuel filter, so I'm wondering if that's the probelm? I did spray some carb cleaner into the carb as well... hoping I don't have to pull that apart.... any ideas what may be happening here? Any help is much appreciated!

[SteveRand]

Hi Chrisnin, and welcome to BGW! You've come to the right place! Now, about your G2...

Was the spark plug fouled with oil, or with carbon soot? Was there oil in the carb? Check the engine oil level - if it is overfilled, oil can be forced into the air cleaner box through the blow-by hose. Replace the paper air filter.

Try pulling the choke partially out while you're driving at full throttle. If it runs better, the carb is running lean. If it gets worse, or there's no change, it's either running rich, or you have mechanical or ignition issues.

Post the results, and we'll go from there...

[chrisnin]

Hi Steve, thanks for the response. The plug was covered with carbon soot. The air filter was (and is still after washing) very oily. I didn't notice any oil in the carb, but I didn't take it apart either. I tried running it while using the choke as you suggested, and it didn't make much of a difference, it still kept cutting out at full throttle and then kicks in again after it stalls for just a second. I changed the oil in the spring and it has been running fine all summer and the oil dipstick reads as being full. Would the air filter being saturated with oil cause this problem? I just ordered a new air filter, foam filter and in tank fuel filter. There was also some oil residue in the bottom of the air box. Thanks again for the help!

[chompy]

It sounds to me like your engine is hitting the electronic govenor. If the engine over revs the eletronic govenor will cut off the ignition for a second and kick back in when the engine slows down. Only fill half way on the dip stick. Change the air filter.

[TROUBADOUR]

I had what appears to be a similar problem last spring. Problem turned out to be the cable linkage -- accelerator pedal to the carb. The clip was loose/worn and with a bit of pressure it would slide instead of move the rod on the carb.

[SteveRand]

If the air filter element is oily, it may be causing your rich mixture - which the sooty plug suggests. Try driving with the air cleaner box disconnected from the carb. This usually causes a lean mixture, and pulling the choke out slowly will correct it. If this happens, the air filter is too restrictive.

Check the hose between the valve cover and the air cleaner box. If it has any oil in it, we need to determine why the engine is pumping oil out through it. If the air filter is causing the restriction, the intake vacuum might be pulling oil into the airbox.

There might be too much oil in the crankcase, or the rings could be worn, and the blow-by is creating too much pressure in the crankcase. It's also possible that the the oil return hole between the head and cylinder is blocked.

Hopefully, it's just a dirty air filter!

A lot to take in here, but just trying to cover all the possible causes.

[Mike Mac]

All suggestions are good, but like Chompy said, first replace the air filter. Washing the paper air filter closed all the pours and now has no air flow through it.

[chrisnin]

Wow, this is one helpful website! Thanks everyone for the suggestions... I'm hoping to get the new air filter by Wednesday, and will start there. I did check the hose going from the air box to the valve cover... and sure enough... there is oil in there too. I'll drain a bit of the oil down and see if that helps the situation. It's strange that it ran fine all summer after the oil change in the spring, but maybe it just took that long to saturate and clog the air filter as I only use the cart a couple hours each week? As I mentioned earlier I'm pretty sure that the in tank fuel filter has never been changed, so I'm going to change that out too. Do those things get clogged up normally? I'm thinking that after 20 years, some sand or sediment from the gas tank may have eventually clogged that filter...

[Flintrock]

Don't change that in-tank filter, remove it completely and put an in-line filter in between the fuel pump and the carb......

[Mike Mac]

Sorry Flint but, I do use the in tank filter. First it is Yamaha, so it's a good one and with the flow rate of these cars, it should go many, many, many years before it needs changing. And any time you can eliminate clutter in the engine compartment I'm for it. Less is always better!