Why my stock 89 2 stroke running lean?

[drifting g1]

I have an 89 marathon. I just put a new carb on it, and everything has been gone through this cart. I have premixed the fuel, no oil injection. I mixed it to 40 to 1. I ran it outside the other day when it was about 50 degrees outside. Take off is good but when it get to the top end, it falls on its face. When I pull the choke out about halfway, it takes off like a rocket, then I can open the choke again. I know there is no top end adjustment on the carb, just bottom end, right? What is causing this when it's stock? Is the mixture to rich with oil? I was told from Ez Go to premix to 128 to 1. I'm pretty hard on it at my campground and was told to do around what I mixed it at. I have a Yamaha G1, 2 stroke, and that thing screams, even when it was colder then the 50 degrees I ran the Ez Go at the other day. Any thoughts? Thanks guys

[Dave Box]

With all that oil running through you will be running lean so it is hardly surprising that you need to restrict the air to get it to run right.

EZGO is correct and whoever told you to mix at 40:1 is wrong. Why don't you mix a tank at 128:1, clean all the oil off the plug and see how it runs.

Dave

[drifting g1]

Originally Posted by Dave Box

With all that oil running through you will be running lean so it is hardly surprising that you need to restrict the air to get it to run right.

EZGO is correct and whoever told you to mix at 40:1 is wrong. Why don't you mix a tank at 128:1, clean all the oil off the plug and see how it runs.

Dave

Ya I think that is what im going to do. Guess I thought more oil cause we beat on them so hard, and run them none stop. But then I have learned on here from reading many post just now that I might have to much oil in the gas which is lowering the amount of fuel to air, causing it to be lean. Should I stick with the 1 oz per gallon ez go says for mild use, or 1 and a half oz for heavy use? Would 85 to 1 be ok or should I just quit being stupid and mix to 128 to 1 lol. Thanks for the help

[Dave Box]

I don't think you are being stupid, I think you are being (overly) cautious. Being stupid would be running it on straight gas because you didn't know what a 2 stroke was.

There are many schools of thought on oil ratios and I can guarantee that several guys will now chime in with their opinions and you should take my advice, and there's, and decide for yourself. That said here is my take. EZGO say 128:1 and that is what I do, they do not say xxx:1 for heavy use. Now I do not have any numbers for the oil pump performance but I have seen the Yamaha numbers and they are 300:1 at 1000rpm to 100:1 flat out. Now the whole oil pump idea was to make the 2 cycle less of a polluter by adjusting the ratio according to need. So assuming that the EZGO Robin engine is somewhat similar to the Yamaha we can see that 128:1 is the setting for flat out use. That said, to be honest, I really don't think that it will make much difference if you use 1 ounce per gallon or 1.5 ounces, so you should do whatever makes you feel good. As I said I use 128:1 because a) it is an easy ratio and b) because I don't want excess oil collecting in my muffler and gumming it up.
Finally (and I can already hear you cheering when I say finally) you should be aware that it is not sufficient to simply toss the oil and gas into your fuel tank. If you do so the oil will sit on the bottom of the tank and make a nasty slick down there. You should add the oil to the gas in a container and shake vigorously to ensure they mix.
Let us know if a thinner ratio cures your problem.
Dave.

[madoc1]

ditto.

[drifting g1]

Thanks for the advice. I only mixed up 1 gallon at 40:1 just to try it out. I do mix it in a jug and shake it good before putting it in the cart. I'll drain out the tank and do the 128:1. Guess I was just trying to over protect the motor. Tired of stuff breaking! The Yamaha did have injection, which I took off. I'll let you know what happenes