max iv running very rough

[cvflats]

I have been working on a 1993 max IV for a while. was left out in the rain for 2 years not driven. guy said if you can make it run you can have it. It has a kohler mag 20 in it. I have rebuilt the carb, changed the spark plugs, and changed the chains. Took it out for a test drive yesterday. Did great for the first 1/2 mile then started running rough and then finally quit. It would start and run briefly with the choke pulled out and i was able to limp home. Let it rest a while and tried again. Ran good for the first 1/4 mile this time and then rough again. Is it overheating? It idles great. any ideas?

thanks

[MaxRules]

Did you clean out the gas tank and put in fresh gas? Is the gas tank vented?

[northerner]

Since it hasn't been running for a while it probaly hasn't seen the new "green" gas with ethanol in it yet. It tends to loosen up any junk in your tank, lines and carb. I had the same prob with my 18 vangaurd and heard of other guys probs to. Cleaned out the carb an she was a gonner again. Just my 2 cents worth

[SlimChance]

MaxRules and Northerner have good suggestions and I would try those first. Something else that would cause this is the coil may be breaking down as the engine heats up. I have seen this happen before on Kohlers. As the ignition coil gets hot, it drops power and shuts the engine down. If it cools off for a couple of minutes, it will restart and run a short time.
Just something else to check on.

[amphibious drew]

Do it once and do it right. clean the tankand carb thoroughly. replace all lines and fuel shut off (or clean shut off). Make sure petcock is clean and clear. make sure gas cap vent is clear. If problem persists its something else because you did everything.

[cvflats]

I cleaned the gas tank and blew out the fuel line with compressed air. Previous owner installed an electric fuel pump which i have replaced. I also put an additonal filter between the pump and the carb. The gas tank is new so i assume it is vented. what is the petcock?

[MAX IV Mark]

check out the lines inside the tank as well. I bought a machine with 1.7 hours on it that did the same thing. It would idle great but as soon as you give it throttle it would die. My lines inside the tank were eaten up and melted from what ever was in the tank. I also blew through them multiple times until I figured it out.

Mark

[amphibious drew]

Petcock is the part that connects your pickup line in the tank to your fuel line outside the tank. if your lines are deteriorating blowing air through them won't fix anything.

[phil_1066]

Had the same problem with a new Max 2. The local kohler agenstripped e carb bfound nothing wrong but put it back together and has worked perfectly ever since. \they think it might have been water in the engine

[tattooman]

change fuel line and try SEA FOAM in the fuel. It keeps things cleen and running smooth.