I guess it’s new rings ?

[Tommybh]

Okay guys how’s it looking so far to y’all what do y’all think I need to do I know I still have to measure and everything but factory cross hatching is still there there are some smudges looks like rust but smooth to the touch no lip or ridge at the top of cylinder idk what exhaust valve spot is from

[Tommybh]

Pics

[CP241]

Maybe just me, but I’m thinking it looks like that motor may have been rebuilt before. The marks in the cylinder and the pitting, looks like it may have sat with water in the cylinder before. and the rust where the head gasket sits, it doesn’t look like a 15 year old motor to me. Too much “wear” but still have cross hatching, and it’s not really worn evenly.

I’d have a machine shop inspect the bore. See if it’s been overbored.

[Tommybh]

The guy who owned it befor had it for 10 years and it sat in his shed and was only driven when his grand kids came to visit I also had to drill out the anti tamper plate from the carb it was never taken off I used a micrometer and dial bore gauge at the tops just now and it’s showing .002 thousands bigger than 2.519 idk how much is too much

[Tommybh]

Also the carb had rust in it reall bad from old gas and I’m thinking it was ran with old gas in it maybe that’s where rust is at top of piston

[CP241]

That may explain it. That pitting can also allow oil to not be “wiped” out of the cylinder and burn off causing smoke. I’d still tear it down, and go through the service manual. Measure everything and compare to specs. Then you can determine what needs to be done to make it right.

[Tommybh]

Okay I know in the rebuild it’s says the spec is 2.519-2.520 and at the top I’m .002 over the smaller number but the bigger number at top .001 over spec how much over is too much over ? Manual says if bottom and top is .004 or more from each other re bore .. does that mean there is .004 tolerance to still use standard rings ?

[CP241]

I don’t know that I’m understanding the question

Assuming you have a bore gauge… you want to measure the bore in several places. Starting about 1” down from the top of the cylinder. And measure in multiple places as you travel further down the cylinder towards the bottom. You can’t do this with the piston installed, at least not accurately.

If you are outside of spec, you’re out of spec. There’s no gray area open for interpretation.

I don’t mean to sound rude, that’s not my intention. and maybe I’m misunderstanding your questions, but others and myself have said that the motor needs to be torn down and everything measured. There’s a spec for every clearance in the motor. And measured with the correct equipment. I don’t understand why you seem to be questioning the advice given and try to find shortcuts. Sure you could probably get away with just throwing some new rings in it with a quick hone. It may last a month it may last a year. But chances are better than not, you’ll be doing this all again before too long. Sometimes you get lucky and a shortcut works. Sometimes you don’t. These robins engines do tend to be a lot more picky about tolerances being right on than others like the Kawasaki’s. And when they run, they run sweet. But something just a tiny bit off, especially in the MCI motors, wrecks the motor to where it becomes cost prohibitive to repair.

Maybe someone else has better or different advice, but I don’t really know what else to say… but measure everything, do what needs done and do it right. Then enjoy it for many years to come.

[Cartmaster]

What he said.

Do it right and it may last another 20/30 years with regular servicing! I agree with CP, it's not worth taking shortcuts. These are the best ever gas cart engines and worth keeping in good shape. Although the mci is not quite as good as the pre mci. Still better than any of the single pot engines. Also best to do it now while parts are still available.

[Tommybh]

Oh no I’m not questioning anyone’s advice I was just taking pictures during the process I’m going to take whole thing apart just what I found so far I was posting .. also I’m just confused by the tolerance in the manual it stats if the taper is out by .004 then rebore I have a dial gauge that is accurate down to .0005 of an inch the top is showing (so far to be .002 bigger than 2.519 ezgo bore spec... but the manual says if top exceeds bottom by .004 then rebore so is there .004 of tolerance allowed before rebore