85 Marathon 244cc Engine Rebuild

[Dabble Inn]

One more

[BBuford]

Love it. I just got a 1986 and I am doing the same thing as we speak. Except, I am letting my EZGO shop put the crank in. It was worth it to spend the $. I painted all the engine covers and various brackets along with muffler. Fixed and installed the 4in. lift. I want to paint mine this winter maybe!

[Dabble Inn]

Originally Posted by BBuford

Love it. I just got a 1986 and I am doing the same thing as we speak. Except, I am letting my EZGO shop put the crank in. It was worth it to spend the $. I painted all the engine covers and various brackets along with muffler. Fixed and installed the 4in. lift. I want to paint mine this winter maybe!

Probably a good idea, I was a bit scared (as you can tell in my above posts lol) when the new crank measured a hair bigger at the bearing mating surfaces for lateral. Plus I knocked it in the old fashion way which I don't suggest unless you've done it before with success LOL.

I'd be very very curious what your lateral play ended up being?? If ya think about it and if it's not too late would you mind asking them when ya pick it up? Thanks...........

Speaking of mufflers I need a new one, When I was handling it putting it back in I flipped it over once and it sounded like a coffee can full of rocks. I tried to order a new one but of course the entire country is on backorder, I will get one when they come in. I would guess the back pressure isn't correct with it anymore

[Dabble Inn]

Update;

Got it completely done and have been running it everyday, It smokes occasionally a bit from the extra rich 40:1 oil mixture. It's about halfway through this first tank and I can't wait to use it up, Then it'll go back to 128:1....

I'll do another compression test after the first tank but it runs really nice so far, I'm at 6000ft elevation and top speed is 22mph by gps...

Here's a few final pics

[Alex Faught]

I can't wrap my head around 128:1, that is super lean! Factory recommended?

[kyerik]

Yes- but these are relatively low rpm/low hp 2 cycle engines. They top out around 4,000 rpm. Chainsaw/weed eater engine rev up closer to 9,000 and need more lubrication.

[Dabble Inn]

Originally Posted by Alex Faught

I can't wrap my head around 128:1, that is super lean! Factory recommended?

Yep that's factory recommendation, honestly I couldn't believe it either when I first got it 17 years ago. 1 ounce oil per gallon of gas.. I even added 1 extra ounce of oil the first time and it smoked a bit, so been mixing the 128:1 ever since..

I'm not sure under load but with the back tires off the ground it revs to 5200 in forward and 5600 in reverse

[racsan]

so (therorecially) it could go faster in reverse? 20+ backwards seems crazy