New to me G29 with a bad smoking habit

[rojo143]

Originally Posted by rstacy

Is the oil level rising?
What you are describing sounds like a cart that has been running on gas with ethanol.
The ethanol ruins the rubber tip needle. Now the needle doesn't seal properly and allows excessive gas in to the cylinder which will mostly burn while the engine is running. After listening to enough engines with this problem you can actually hear the problem when the engine is starting. Its a slight burble sound as the engine starts.
The bigger problem is that while the engine isn't running gas continues to siphon in to the cylinder, past the rings and down in to the oil. Now the thinner oil gets past the rings and causes the engine to smoke and contaminate the muffler so that even after you replace the needle and change the oil, the car will still smoke for about an hour while it burns the crap out of the muffler.

Of course it could be that your rings are shot and its time to hone the cylinder and install a new set of rings. This is probably the case if your oil level is not rising over time.

No the oil level is not rising today I notices I am down a bit on the dip stick after the little bit of driving I did on it over the weekend. So looks like I will be cracking the head off of it after the holidays. When I do I plan on inspecting the valve seals, the cylinder and piston to see if I can get away with just do rings or not. Thanks for the input.

[Rob_C]

It's common for the oil rings to relax if the engine has gotten too hot. I've lost count of the number of rebuilds I've done for that reason and have two G29s here to do at the moment. They start and drive fine but smoke like there's no tomorrow. Usually when taking the plastics off the engine you'll find grass, dirt, mud etc jambed in the fins and blocking airflow.

Clean the lot, hone the bore lightly, replace both crank seals and the valve stem seal while you have it apart. If you figure it has some wear, replace the piston while you're at it.

Pick of a previous example for your amusement.

[rojo143]

Originally Posted by Rob_C

It's common for the oil rings to relax if the engine has gotten too hot. I've lost count of the number of rebuilds I've done for that reason and have two G29s here to do at the moment. They start and drive fine but smoke like there's no tomorrow. Usually when taking the plastics off the engine you'll find grass, dirt, mud etc jambed in the fins and blocking airflow.

Clean the lot, hone the bore lightly, replace both crank seals and the valve stem seal while you have it apart. If you figure it has some wear, replace the piston while you're at it.

Pick of a previous example for your amusement.

Thank you for the insight. When I first bought the cart the fan duct on the passenger side was filled with grass and other debris, but I never thought to clean out under the cylinder covers. Guess I will add that to the list of to-do's. The cart only really smokes when it first starts up and gets going after about 500ft of driving it stops, so that was making me think it would be a valve seal or something else that expands after it gets warm. Since I just replaced the fuel pump the oil no longer smells like gas, but it is burning oil. I am getting a borescope today so I can look down inside the cylinder to get an idea of what needs to be done and if I can get away with just honing it or if it will need to bored. I will upload some pictures of what I find to get some more experienced opinions.

[rojo143]

Well after a quick ride to the front of my neighborhood (maybe 10 minute round trip) I got back home let the cart cool down and then scoped the motor. Found the source of the initial smoking issue. The head will be coming off over the holidays and getting rebuild and I will more than likely hone and replace the rings on the piston as long as the cylinder looks OK. Tha k for all the help thus far everyone!

[rstacy]

Originally Posted by rojo143

Found the source of the initial smoking issue. The head will be coming off over the holidays and getting rebuild

Wow! I have never had one that bad. You going to have to do more than pull the head.
Start with pulling the engine.

[rojo143]

Originally Posted by rstacy

Wow! I have never had one that bad. You going to have to do more than pull the head.
Start with pulling the engine.

Yeah I agree and the engine will be coming out just not at the current moment. It cannot be that bad considering the smoking stops after the engine warms up(granted I have no experience with these motors), but there is not that much to this engine and can only be caused by about a handful of different issues. In a car engine my first attempted fix would to be to inspect the head, valve, valve guides and seals. If I see any issues I will correct them and see if it gets any better. While I was scoping the cylinder I did not see any major signs of damage or wear on the bore and the piston had a uniform gap to the cylinder as I moved it though its stroke. I will tear it open after the holidays and report back my findings.

[Rob_C]

Yep, relaxed oil rings. I've found more oil than that on top of the piston, makes you wonder how it still runs. A quick hone, new rings, gaskets and seals and you'll be smiling.