1985 Honda ATC70 Problem(s)....Motor Time

[kzr800]

O.K., I have a problem and I need to make some fast decisions, so I can get my ATC 70 back in action ASAP. Over the weekend, my ATC 70 was running great and all of a sudden died. It has no spark….I decided to look into the stator & points first….I realized I broke of the flywheel key. The crank is messed up and so is the flywheel.

My question is should I tear into the motor, put a new crank and do the 88cc big bore kit, or do I just buy a motor (Pitster, Liflan or Piranha)?

My 10 year old rides it most; however, he also has a fully mod KFX80. I’m not worried about the power so much, as he knows how to ride. The truth is I want to play with it too…LOL. After seeing the build for Trikefest (Planning on going for the first time this year) and looking at the photos on Spangler’s site…..I can see myself doing a serious build.

I’m all ears and if anyone has a motor for sale, let me know.

Thanks,
Karl (KZR800)

[briano]

My current "fun" 70 has a china 110 motor in it with the recoil conversion. It has the stock 70 exhaust and up until last fall had the 70 air box. It hauls my 6'3" 250 pound butt around very well. So far it is my favorite 70, it is a 4 speed semi auto but I'm not sure of the brand. I had a 70 with an atc110 motor with a 10.5 to 1, 123cc big bore with a cam, pipe and carb. I also had a 70 with a 140 piranha motor and the china 110 is my favorite so far for the riding that I do. The 140 was a beotch to pull start but fast as hell. The big bore 110 was also fun but finicky with the big cam and jetting. Also with the china 110, it's hard to tell from 20 feet away that it's not the original motor. And I did not lengthen the frame with the 110 like I had to with the other big motors. If I ever build another one it will be a china 110. Well, that's just my opinion and I'm sure there are many more. Good luck with your build.

[86125m]

Hmmm id try to find another 70 motor personaly I don't do chinese motors.

[jb2wheels]

How bad is the crank?
Flywheels are cheap.
I don't like splitting cases - never done it so I'm intimidated by it - so I'd buy a Chinese clone.You can probably score a whole ATV or dirt bike off Craigslist for a couple hundred.

On the other hand, 70 motors and parts are cheap. I put an 88 kit on my TRX - just the cylinder and piston kit from DRATV. Hauls ass. Uses stock head, carb, pipe, airbox and still hauls ass. The stock 70 engine did not like me since I weigh almost 2x the whole quad.

[kzr800]

The crank is bad....I was able to pound the nut on far enough to grad a few threads.....then I tack welded the nut on. It runs great, but my fix is only temorary so the kids can ride it while I buy or build another motor.

Anyone else have some feedback?