1987 marathon 2 cycle having problems

JoshKent

So, I bought this thing off of Craigslist and it has a problem where it moves slowly in forwards and fast in reverse. We replaced the secondary clutch, the drive belt, brushes in the starter, and ground wire. The engine has good compression (95 psi forwards 105 psi reverse) and the forward reverse switch is good. It has a robin ec25-2pg 244 cc engine.

BGW

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

cart around

I would say take the belt off, and push the cart forward, and reverse on concrete to see if there is a difference in rolling resistance. You could have some dragging brakes in one direction.

Does it seem like the engine is running the same in both directions?

If all else fails, study this manual front to back, and pay particular attention to page H-17 figures H-18, and H-19.

Attached Files

85-EZGO(2) (1).pdf (6.71 MB, 0 views)

JoshKent

We put it on a 2 post lift and turned the tires, the tires made almost 2 full rotations. The engine does run opposite direction in reverse, my instructor thinks it might be the magneto


Sent from my iPhone using Tapatalk

cart around

Can I say this really politely? Your instructor doesn't know what he is talking about. (I used harsher words, and then erased them.)

This cart has an electronic ignition. There is no magneto.
I already know that the engine runs in both directions. I'm asking if it runs stronger in reverse. Not faster, I already know that. I want to know what it sounds like compared to forward, and reverse.

If the engine itself is actually running stronger in reverse, it is probably time for crankshaft seals. That's why I told you exactly what page to read in the manual.

Two different compressions like that also tells me that this engine is almost worn out.

JoshKent

Give me a little bit and I’ll get a video for you

JoshKent

It is definitely stronger in reverse

cart around

I'm going to bed until 4 PM. I just shot a couple thousand rivets through the new cockpit skin of an Airbus A321. I'm tired.

Study the manual, and look up different threads on crankshaft seals. Remember this, seals have no affect on compression.

One more thing 120 PSI compression is new. 100 is perfectly acceptable, but that much difference between forward, and reverse means something is worn. (probably rings)
The piston moves up, and down no matter what, but the crankshaft puts a different side load on the piston depending on which direction it's turning. Compression changes with a loose piston.

You should also change the plug, and check the exhaust for obstructions.

Spicyunicorn

Does it run better in forward if you mess with the choke?

JoshKent

No, it does not


Sent from my iPhone using Tapatalk

cart around

I'm assuming that you are taking small engine repair at a vocational high school.
This sounds like a senior project.

We can help you through this with the least amount of money, but you have to understand that 2 stroke golf cart engines are different than the typical B&S, or Tecumseh engine in the lawn mowers they are showing you.

Your golf cart engine runs forwards, and backwards. Is very low compression, and is designed to start, and stop every time you drive it. It does not idle.

Study up the manual to get familiar with everything. You are going to need a steering wheel puller, and an impact to remove the flywheel. You will also need a 3/4" fine thread bolt, and some grease to remove the drive clutch.

https://www.golfcartking.com/ezgo-cr...cle-1980-1993/
There are two of these seals. When they start to go bad, the typical symptom is running better in reverse than forward. That's because the engine spends most of its time running forward, and a wear pattern sets in. Changing direction makes them seal better.

You may also need bearings, and rings. It depends on how much you want to spend, and how deep you want to go in this project.