Hello all,
Thought I'd start a build thread to document the revival of my 82 ATC110.
I bought this on a whim last night, after deciding that I really want to go off roading with my friends but wasn't all that interested in a dirt bike.
While very rough and very incomplete, I have enough experience with old junk that I decided it was worth the risk and the challenge of bringing this parts bike back from the dead, and returning it to running and riding condition.

Might as well start with the overall condition of this thing.

The bad:
The gas tank is very rough and incorrect, I believe it is off a 1980 model. The seat is just foam and a cover, the pan is nearly nonexistent. Carb, exhaust, and recoil start are all missing. Plastics are in poor shape, missing large chunks, and have extensive zip tie stitching repairs. Both the front fork bearings and the rear axle bearings are shot.
The engine was stuck from sitting open to the elements and the sub-transmission has been cannibalized for parts. This thing has clearly been crashed. Handlebars might be bent, and the skid plate is mangled.

The good:
Aside from all the missing accessories, the engine internals are all complete and while the oil is dark, it's at least full of uncontaminated oil. The main transmission shifts through the gears, the tires hold air, and the whole thing rolls and steers. The numbers on the engine and frame both agree that this is an 82 ATC110, so at least my stuck engine is correct to the thing.

Right when I got it home, I tore into it a bit. I pulled the engine out and got the jug and cylinder separated. While the bottom end and valvetrain appear to be in decent shape, there's rust in the jug and scoring on the piston. The right thing to do would be an overbore and matching piston. I inspected all of the CDI parts and while it's all there, I'm not sure that the coil is correct. The wiring is in poor shape so I expect that, if nothing else, a full rewire will be required to get spark.

For now, I started with a parts order. New bearing kit for the forks, bearings and seals for the rear axle, JIS manual impact bits to get the engine covers off, and a set of good used sub-transmission internals. All that seems to be missing is the countershaft, but I found a whole set of internals for a good enough price that it made sense to buy them all.
Still doing research on options for the piston and cylinder jug, if anyone has suggestions I'm open to them. Same for the recoil start, if recoils from other engines can be retrofitted, I'd like to avoid the expense of buying a used "correct" recoil for this.

If you've made it this far, thank you for stopping in and reading! I can't wait to start making this thing better!
Click image for larger version. 

Name:	20240228_213557.jpg 
Views:	27 
Size:	354.6 KB 
ID:	271237Click image for larger version. 

Name:	PXL_20240229_044506523.jpg 
Views:	25 
Size:	1.12 MB 
ID:	271238Click image for larger version. 

Name:	PXL_20240229_044523699.jpg 
Views:	29 
Size:	1.17 MB 
ID:	271239