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Topic: Wheresthericego's 1983 ATC250R "air fooler" (Read 21782 times) previous topic - next topic
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Wheresthericego's 1983 ATC250R "air fooler"

I know this isn't a "quad" but it is becoming quite the project so I figured it deserved its own little slice of TQC heaven.
 
It all started with an engine missing 5th gear.  The engine came out of the frame approximately a year ago but I didn't get my hands on it until about two weeks ago.
 
The determination was made to split the cases and swap out the tranmission.  When I removed the top end, I found this gem:
 

 
Not too bad on that side, some light scratches possibly some evidence of a cold siezure. It looks bad but really, that's just a lot of staining.
 
The exhaust side, however:
 

 
That's not just staining....  That's actually coke (ash) built up in rather large gouges in the piston thrust face.
 
I measured the top end and it's about .002" tapered down through the middle, enough to be slapping around in there.
 
Of COURSE, this top end is on its last life, .080" (72mm) oversize....  I am, however, leaning towards fitting a TRX310 .010" piston (72.25mm) in it and the spacer plate necessary to run it.  It means removing material from the top of the block to the tune of 3/16" but I believe it can be made to run (and run well) and this leaves LOTS of options for piston overbores (the 310 kit runs from 72mm to 73.5mm).
 
I want to talk to cometic about a spacer plate and LA sleeve again about the piston before pulling the trigger on a fancy new piston not being 100% it's going to fit  :-
 
 
More pics as the work gets done!
Click on the pic VVVV You know you want to....


Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #1
Sounds like quite the project you have! Looking forward to hearing the outcome.


Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #2
yea me too!


Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #4
Waiting on money and getting a new piston.  It's shelved for at least another week.
Click on the pic VVVV You know you want to....


Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #5
Looking Forward to this one ! .

Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #6
Need to update.  I found a guy who had a bunch of cylinders (7 to be exact) and wanted to get rid of them.  $40 a piece so I said, "two please!".  I'm waiting on them to arrive now.  Once I see what kind of condition they're in, I guess we'll go from there.
 
On a side note, we have some tires on the way already.  Thanks to Bruce, who located them on his local CL and went to meet the guy to pick them up!  Stand up guy, guys!
Click on the pic VVVV You know you want to....


Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #7
Cylinders came in today.  Hot snot, we're back in business.  One is .060" with only some minor damage that will clean up at the next overbore.
 
One is completely stock but with some reasonably deep scrapes up the cylinder wall.  I suspect they'll clean out of there at no more than .020".  MAJOR score on these!
 
Now the "only" things left are to to build a jig using my I beam and make a ladder frame swingarm, buy a sheet of steel and build a custom drag pipeb and finish off the bottom end.  LOL Nearly there?   :o
Click on the pic VVVV You know you want to....


Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #8
heck yeah really good score on those cylinders ! . What no Picks of the 4snow's haha jk ..

Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #9
:P maybe pics of the 4snows tomorrow.... :P
 
I'll also snap pics of these cylinders tomorrow too ;)
Click on the pic VVVV You know you want to....


Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #10
I worked a little bit today on this monster.  No pics of the 4snows :( but I did snap a few of one of the cylinders :D

The goal here is to have a reasonably competitive heads up ( hand drop style) drag trike with the possibility of putting it in the sanctioned races too.  I'll be building from scratch a lot of the modified parts needed to accomplish this.  That will include an OOF pipe, ladder frame swingarm, intake manifold, possibly an air horn, and possibly a wheelie bar.
The first step was to clean it down and see what we had:
 

 
.060" currently and needing to go to .070" Perfect candidate for this build.  Enough lives to make it worth while.  Not so many lives to ruin it by doing a drag port job on it.  I have a little more media blasting to do, I know.  There's a little red paint left but I'll be sure to get it all before it's done!
 
One of the first thing to work on for me is the exhaust pipe cylinder adapter (starting small  :D ).  I contemplated using the stock cylinder adapater for a while but decided to make my own.  I have an issue with cutting apart stock vintage parts normally but this one had to sacrifice itself for the cause.  Don't worry, this won't be a theme!

I just bored the original pipe out of the center of the flange:
 

 

 
I then turned a piece of pipe down to size and made it a snug fit inside the flange and weled it all together.  I have the new one sitting next to a stock one.
 
"Outside":
 

 
"Inside":
 

 
And mounted on the cylinder:
 

 

 
Click on the pic VVVV You know you want to....



Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #12
Excellent work on that flange! Those welds look great! Tuned in for this build  8)

Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #13
Just fillin' it in, walking the cup.  ;)
 
I was thinking about splitting the cases on this monster today.  Haven't decided to pull the trigger on that one yet, though.  I've got to clear the work bench for that one and keep it clear until it's complete....  More pics and updates to follow!
Click on the pic VVVV You know you want to....


Re: Wheresthericego's 1983 ATC250R "air fooler"

Reply #14
Nice job james i can see this is going to be some build  ;D
You've Just Been Smoked By A 2 Stroke!