Aero 125 help

[jwhite2]

Hey guys,

Thanks for the tips. Sorry I have been absent the last few days from this thread. My first child was born early Wednesday morning. Baby girl, 7.7 lbs, 21 inches. //end proud dad portion.

Got a chance to get out and work in the shop some today. Took noiseguy's advice to throw some two-stroke gas into the crank area to see if I could rinse anything out. Got several bits of the piston rings out of the bottom. Now it is free and rotates easily. Added some more 2 stroke oil back to it.

So do me a favor, go back to my flickr photos and look at the cylinder. I am really debating just finding a NOS piston and cylinder head to replace my busted ones and bolting the cylinder as-is back on. That plus new seals and maybe I will have the compression I need to get this thing started. I also plan to get the original carb and air box from motormike as soon as he messages me back.

Anything else I should take a look at before investing any money? Hoping that $300 worth of parts gets me back to running condition.

Thanks

-J

[noiseguy]

Congrats on the new baby!

You can go that route. Your final compression won't be as high as it would be with a bore and oversize (OS) piston.

If you put in a stock size piston, you'll want to try to get the oversize rings to go with it. They make a stock and a .1mm oversize... get the latter if they are available. You can then file the ring gap to spec. This should be described in the service manual. Otherwise, use stock.

Get a ball hone and hone it out that way. These typically run ~$25 and can be bought off Ebay. They are sold by cylinder diameter. Follow the directions. Doing this will seat the new rings.

I think you'll need to chamfer the ports after this... hit them with 220 and dull the knife edges off the exhaust and intake ports on the inside of the cylinder. These knife edges eat rings.

Clean it up with soap and water to remove grit from hone and sandpaper, and dry/oil cylinder.

That's it. If you're trying to stay cheap, I would fix the head by hand. If your time's more valuable than $, buy a better used one (but in that case, you should probably overbore it...)

[Johnniespeed]

It was mentioned earlier in this post to use a 1982 CR125 piston in the Aero 125 engine, however the piston is not correct, the ring gaps are not in the correct location.
If anyone knows how to modify the piston to fit please post the information.

[Aero125]

Revival bump, picked up an Aero 125. It does not need a top half yet. It has 5000 miles and it might someday so I was hoping to have the items I need on hand.