1983 Marathon Engine Trouble

[ScooterMcTavish]

If you have access to a machine shop, you can get these jugs bored out, and there are oversize pistions available for the engine (click on the site sponsor link at the top). Just note that the tolerances on these engines are very tight (.007" between the cylinder and the jug). A much cheaper way to do the rebuild if you have access.

If the cylinder isn't damaged, you can always hone it out, and try some upsized piston/ring combos, but the learned folks here suggest that these cylinders wear out of round. Might be worth a try if you wanted to go the cheapest route - just make sure you've got a good inside micrometer before pursuing this.

[devadasy]

thre are engine shops around here that should be able to redo the cylinder and many machine shops also in the area. as for damage to the cylinder when I lowered the piston it looked and felt nice and smooth. the piston is what looked a little beat up on top and on 2 edges. it looked like tool marks on the edge. this weekend I should be pulling the cylinder off to look at the shape piston the rings and cylinder are in. to me it looks like the piston took most the wear.

[devadasy]

the other thing is without a service manual I have no idea how to remove a muffler on a 83 since it is the only year of that style

[Dave Box]

oops posted in the wrong place

[devadasy]

The piston inside engine looks like its missing a ring and cylinder does not look the best



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[ScooterMcTavish]

Still thinking a top end kit might be the way to go. Once you add in how many hours you'll waste if the rebore doesn't work, it seems like "better safe than sorry" might be a good mantra.

Hard to tell looking at the cylinder photos, but the piston does look cooked on it's top ring. Likely means significant cylinder damage.

[racin161]

Bet I know where the dents in the piston came from. A broken ring ?????

[Old Browny]

Originally Posted by Dave Box

The bottom line is that with the piston loose in the cylinder and less than 90 psi it is shot so don't even bother measuring it. As regards a manual you will be hard pushed to find one for an 83 -1983 was the oddball year for the 2pg engine. The muffler was placed behind the engine and it layed down instead of standing up. The '83 golf cart had a different engine frame, muffler & exhaust stack. It only lasted one year though...lots of problems. However the manual is pretty generic so as long as you get one for 81 - 88 that will be fine.

Of course if you go down the route of replacing the top end (and as BCM says, you must also replace the Crankcase oil seals) then there are plenty of guys here who will help you. In that vein here is some advice. Grab hold of the clutch that is attached to the engine, now try to move it up and down. If it moves you have crankshaft bearing issues and this is going to have a huge effect on your future decisions.

Dave

Hello Dave Box Some thing queer here I have this 1983 model ,Confirmed by Ezygo as 1983 from the MFG code. In mine the muffler is in the vertical position as pics sent in to Pachango 90 will conform. While talking to you you seem to know a bit about the cluth system. Can you tell me if the clutch system can be accessed fro the back end of the cart . I need to look at the clutch drive as apossible cause of a clanking sound that I have refered to in previous posts