1989 marathon

[CP241]

I just picked up an 89 marathon for 250 bucks. She ain't a looker, but theres little to no rust, and mostly minor cosmetic issues. if I dribble a little gas in the spark plug hole shell sputter a bit so I know itll run. Exhaust is puffing air, compression is 115-120psi, nice fat blue spark, , but carb barely (if at all) sucka my hand while cranking. Absolutely no idea when it ran last, judging by the corrosion and surface rust on the clutches it's been a while! and pushing this sonofagun is one heavy sled!

I'm thinking crank seals are shot hence the lack of vacuum on the carb. So I'll have to I'll have to pull the motor and do those. Is there anything I may be missing, or should inspect/replace while I've got it out?

[LukeL]

You are the gas expert, not me, so explain this to me if needed, but I thought the crank seals were in place to cause vacuum in the crankcase under the piston to make vacuum for the fuel pump... if that’s the case, they shouldn’t affect vacuum for the carb, as that’s above the cylinder?

I know with both of the 3PGs I had changing the crankshaft seals didn’t affect compression or carb suction.

[cart around]

Originally Posted by LukeL

You are the gas expert, not me, so explain this to me if needed, but I thought the crank seals were in place to cause vacuum in the crankcase under the piston to make vacuum for the fuel pump... if that’s the case, they shouldn’t affect vacuum for the carb, as that’s above the cylinder?

I know with both of the 3PGs I had changing the crankshaft seals didn’t affect compression or carb suction.

I can explain this a little bit.
There is a port in the side of the piston. It allows the fuel/oil/air mixture to travel under the piston, through the lower end to lubricate the bearings, and then through another passage on the other side of the cylinder that leads to the top side of the piston for combustion.

That's why the crank seals are so important. Everything needs to be airtight for the proper suction to happen.

[LukeL]

Originally Posted by cart around

I can explain this a little bit.

There is a port in the side of the piston. It allows the fuel/oil/air mixture to travel under the piston, through the lower end to lubricate the bearings, and then through another passage on the other side of the cylinder that leads to the top side of the piston for combustion.



That's why the crank seals are so important. Everything needs to be airtight for the proper suction to happen.

Makes sense. I do remember having to orient the piston correctly when rebuilding mine. I did get it correct on the second try!

[CP241]

Originally Posted by LukeL

I did get it correct on the second try!

I tried to warn you before hand... those pistons are directional! Luckily you caught it early. Most of the time it'll wreck the cylinder when you install it backwards.


but back to the original question, i've never worked on one of these motors specifically. When I have it pulled out to replace the crank seals, is there anything else I should pay particular attention while it's out? I'd really rather only pull it out once.

It's a cheap cart and I don't really intend to do a "full restoration" on it. (I also picked up a cheap gas DS I'm going to go through and make really nice.) I was just going to make this ezgo run right, and redo the seat so my kids can drive it around for the summer. and then end of summer, do a little paint and trim work on it to make it look presentable and sell it when they go back to school in a few months. Right now the task is to just get it to run like it should. I can get the crank seals up the road at my local dealer, I just wanted to make sure there wasn't anything else I should replace while I'm in there (points??? Not sure what kind of ignition this has...)

[Dabble Inn]

Good news, There's no points on an 89. Sounds like ya picked up a nice one for the money, How bout a pic?

[CP241]

Compression is fine. Theres no vacuum on the fuel pump at all either. It doesn't even dribble. I'm guessing they're sucking in as much air as the carb is, reducing the amount of suction on the carb. There is a little there, but not a lot.

Good news, at least the carb actually says mikuni on the side. And it definitely looks original. He said he replaced the carb... sounds like another one of those "tall tales" sellers tell

[CP241]

it's 100% complete. motor spins over good, has a good battery, etc. It's just ugly, but for the price it definitely has potential to be pretty nice, even for just a cheap cart. I won't be putting buku bucks into it, because these are probably only worth around $1500 here clean and in good shape, but i'm into it cheap enough if I can clean the carb up and have it running good for $20 in a couple seals and a few hours of time, well worth the investment :) And when I'm done with it, will make a perfect hunting cart for someone.

Does anyone know where to get the rear fender caps? I've found front cowls for around $40 but the fender caps seem to be harder to find. They're there but have holes in the top of them from sun damage. The rest of the body is in really good shape, but the mercedes emblem and the lights gotta go

[Dabble Inn]

I did a search for 'Ezgo rear fender caps' 71-94 comes up a lot, New for about $32ish each

[LukeL]

That front cowl is the biggest pain to replace- but it’s worth it. Makes a big difference.