Any ATC70 guys on here! Custom ATC70 build.

minibikedude

minibikedude

Active Member
#1
#1
I thought I would share this on here. I now some of the members also have ATC's. I been reading this builds on 3wheelerworlds.com. I,m impressed with this guys build. It's really neat to see what guys do to these ATC70's.



Here is the link on the rest of the build.


bw80 to atc70 conversion.


I,m 80's atcdude on that forum.
 
minibikedude

minibikedude

Active Member
#6
#6
dobber said:
I picked up a ATC110 last week, I plan on going with a Lifan 125cc just to get it back up and going.
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It can be done but you have make some adapters to fit the frame. Those engine have a different mount to them than the original ATC110 engine. Also you will need a electric start engine to work in a 110. Or you will have to remove the seat every time to kick start it.
If your ATC110 engine is good just get a Rocky 4+mm performance piston for it and have the cylinder bore out. It will bump you to 121.9cc and up the compression to 10:1 instead of 8:1. Port the exhaust side of the head to open it up and get a DG or Cobra header for it. Also re-jet the carburetor and you will be surprised how much better a 110 runs.
 
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dobber

New Member
#8
#8
minibikedude said:
It can be done but you have make some adapters to fit the frame. Those engine have a different mount to them than the original ATC110 engine. Also you will need a electric start engine to work in a 110. Or you will have to remove the seat every time to kick start it.
If your ATC110 engine is good just get a Rocky 4+mm performance piston for it and have the cylinder bore out. It will bump you to 121.9cc and up the compression to 10:1 instead of 8:1. Port the exhaust side of the head to open it up and get a DG or Cobra header for it. Also re-jet the carburetor and you will be surprised how much better a 110 runs.
Click to expand...
Thanks, I will look into the the engine upgrades. if I do that I get to keep High Low on it too.
 
zeeman

zeeman

Active Member
#9
#9
The atc's are nice, but I like the two wheel version idea a little better. I've been looking for an atc 70, 90, or 110 for a couple of years, but they are hard to find, and expensive down here.
 
minibikedude

minibikedude

Active Member
#10
#10
dobber said:
Thanks, I will look into the the engine upgrades. if I do that I get to keep High Low on it too.
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I diffidently keep that Honda 110 engine if possible, The high low is worth it. Look on ebay they have the Rocky 4+mm over piston on there, That's were I got mine. I,m building 2 - ATC110's engines right now.
 
minibikedude

minibikedude

Active Member
#11
#11
zeeman said:
The atc's are nice, but I like the two wheel version idea a little better. I've been looking for an atc 70, 90, or 110 for a couple of years, but they are hard to find, and expensive down here.
Click to expand...
It's funny when I not looking for them, I stump across a deal I can not pass on. I just pick up another 1985 ATC110 for 120 bucks with good rear fender clean gas tank and seat/seat pan. It had no spark, Found a bad stator. I got it running already and it will get restore also. I love working on the Honda Horizontal engines.
 
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dobber

New Member
#15
#15
Well, got my bike today. It started 2nd pull, but the clutch is completely out. But the funny part is that he said he just had it changed a year ago for 165 dollars.



 
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dobber

New Member
#17
#17
well found part of my problem. I pulled the rubber cover off to try to adjust the clutch screw, and found that the threads are stripped on the nut a screw, plus I am not able to turn the screw at all. It feals like it is crossthreaded, and it striped on the end.
 
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junkcollector

Member
#18
#18
Back in the early 80's i bored and stroked a atc 11o to 151 cc added a cam and pipe would pull anything but kept burning out the auto clutch , so i converted it to a s 90 manual clutch worked great good luck with your projects .:thumbsup:
 
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dobber

New Member
#19
#19
may do that with mine then. I repaired all the broken stuff, but the clutch still just grabs one time then free spins. I think I am going to put in a new clutch, but I have to use a easy out to get the screws out of it. Also found sombody tried to use a big screwdrive and hammer to get the center bolt out od the clutch, so my tool for it will not work.
 
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