Rebuilding a 80212

poorboy

poorboy

Member
#1
#1
Got it torn down last night and had a couple of questions. This will be for another Atlas that I'm rebuilding for my girls to ride around the block.

Everything was pretty clean.

The intake valve was stuck really bad with and after some work it came out. It is slightly bent and you can see light when shined in from the valve spring box. I'll get a new one for sure

The piston has one score line that you can hang a nail on. It starts just above the skirt and doesn't make it to the first ring. QUESTION. Can I just hone the block, it's in very good shape and use the piston as is with new rings or will that scoring come back to bite me in the butt?
 
125ccCrazy

125ccCrazy

Well-Known Member
#2
#2
the piston should be fine, just make sure that there isn't any burring on the score mark..... Don't go overboard on the honing with a cool bore, just lightly deglaze it...... some guys just ring it without honing but I always lightly hone the cylinder unless it's excessivley worn.... Check the bore by squaring up a ring in the bore at various depths like 1/4" down, 1" down ect and check the end gap at each depth...this will tell if the bore is tapered or not and if it will need bored to get it straight again...
 
poorboy

poorboy

Member
#3
#3
Thank you sir. Cylinder wall and piston show no signs of burning at all. This is a 69 model and internally is in very good shape...I imagine that intake valve being stuck closed saved this little guy from certain torture.

Any advise to getting the flywheel off? I don't have a puller but should probably just go buy one. Once the screen is off there are no other fasteners correct?

Points gap? and I'm sure I should replce the condensor as well?
 
125ccCrazy

125ccCrazy

Well-Known Member
#4
#4
poorboy said:
Thank you sir. Cylinder wall and piston show no signs of burning at all. This is a 69 model and internally is in very good shape...I imagine that intake valve being stuck closed saved this little guy from certain torture.

Any advise to getting the flywheel off? I don't have a puller but should probably just go buy one. Once the screen is off there are no other fasteners correct?

Points gap? and I'm sure I should replce the condensor as well?
Click to expand...
I would suggest a puller, you don't want to hammer on the flywheel or the end of the crank....

Personally I would plug the little hole for the accuator for the points and put a new solid state coil on it and eliminate the points but if you want to run the points the gap is .020 and defininetly replace the condensor....

The easiest way I found to lap in valves is to get some two part 5 min epoxy, clean the valve head and an old lifter real good with lacquer thinner , acetone, rubbing alcohol .... not all three but one of those, even brake cleaner... mix a small amount of epoxy and glue the lifter head to the valve, get the valve and lifter as close as possible to being centered... let it cure over night and then use a cordless drill, chuck the lifter in the drill and run it slow periodically putting valve grinding compound on the seat of the valve until you get a nice grey line all the way around the valve and seat.... make sure there isnt any pitting in the seat also..... Oil the valve stem before grinding to prevent any friction...
 
poorboy

poorboy

Member
#6
#6
OK, got it all back together and she runs great. One last question. The recoil starter like to try and remove my arm from time to time. What causes these little motors to suck the rope back in so violently? One time it actually broke the plastci t-handle.
 
poorboy

poorboy

Member
#8
#8
So, if the key sheers, wouldn't the flywheel sping freely on the crank? I guess the only thing holding it on would be the recoil clutch?

I'll check, just trying to visualize what is going on if that is the case.
 
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