Fixing Up Old Marathon Carts

[Dave Box]

82 and 84 are great years. Believe it or not 83 was a bad year. EZGO made several "improvements" in 83 most of which were deleted in 84. All your parts should be interchangable so you have a good donor cart. The oil ratio is 128:1 (yes I know that sounds dreadfully lean but trust me on this). This works out to be 1 ounce of oil to 1 gallon of gas. It is not sufficient to pour oil and gas into your fuel tank, in fact I am willing to bet that the bottom of both of your tanks are lined with a nasty tar residue, this is undissolved oil. You should pour the oil into your gas container and shake vigorously to mix the gasoil before you pour the mix into your fuel tank. The one exception to 128:1 is if you rebuild your engine then you should break it in with a tank at 40:1 (3 ounces to the gallon)

Dave

[TouringArtist]

The mixture should be 40:1.

[pachanga90]

I'm with DaveBox,The ratios are 40:1 break-in,128:1 running.I run 1-1/2oz per gal,but i run mine hard,ungoverened and flat-out for good stretches.I've run it like this 2 years(heading into 3),no problems.My Dad has run his like this since 99',only went thru motor once when it broke a ring.Other than that it was perfect,no scuffing,hot-spots,etc..Hope this helps.

[bud light]

Welcome Old Pike
You will get hooked.

[Dave Box]

Originally Posted by TouringArtist

The mixture should be 40:1.

You really shouldn't pull numbers out of the air and present them as fact, someone might believe you. 128:1 is what Robin wrote as the spec for the 2PG engine and this is what EZGO quote in their manual. Of course you can use whatever ratio you like, it's your cart, however if you are laboring under the impression that if 128:1 is good then 40:1 must be three times as good I'm going to burst your bubble.

There is no oil pump in the 2PG engine. It relies on the swirling action of the crankshaft counterweights and crankcase pressure to distribute the lubricant. The crankshaft bearings are gravity fed through small galleries in the crankcase. Using an unduely rich mixture of oil runs the risk of blocking these relatively narrow passages with a gloopy mess.

Unburnt oil is just going to pass through the engine and collect in the muffler which will eventally block up. Even a partially blocked muffler will rob the 2PG of power and at 9 hp it has precious little to spare. For further information search this forum for "barbeque muffler". In fact I suggest that you light a fire under yours now, you will thank me tomorrow.

Any 2 cycle engine is a polluter, it's inherent in a design that has the inlet and outlet port open at the same time. http://en.wikipedia.org/wiki/File:Ar...e_Zweitakt.gif
Any oil that escapes from your muffler is just going to lay on the ground and eventually get into the water table causing yet more health issues for the population. If you can see a blue cloud behind you then you are running too rich.

In addition the designers of your carburetor went to great lengths to get the jetting just right. By overdosing on the oil you are inadvertantly changing the fuel / air ratio. This has the effect of increasing the air part of the ratio and making the mix leaner. Leaner engines run hotter which is counter productive for an air cooled engine.

[EZGO-MY-WALLET2]

wow, 128:1...I wouldn't have thought that. I have a sparky, but still good info to know. Good luck on your carts and look forward to some pics....

[OldPike]

Wow. Thanks, Dave. I'll try that out ASAP. Maybe I can get this thing up and running soon. Yeah the tank was pretty caked in grime but I cleaned that out. If I can get this one running I'll try and get some pictures up. If you can still point me in the direction of a marathon manual that would hekp a lot. Glad to hear that I have two good years though.

[black_hemii]

my cart is an 87 ezgo pre medalist with 3 pg robins engine i rebuilt about 3 months back because of tinging noise and it still does but only in rev but runs great anyone know why

[rokcrlr]

Originally Posted by black_hemii

my cart is an 87 ezgo pre medalist with 3 pg robins engine i rebuilt about 3 months back because of tinging noise and it still does but only in rev but runs great anyone know why

Did someone put the 3 pg in your cart? The 3 pg didn't come out till 89