Converting a ATC 70 to a 125

[oemstunters]

Hey whats up everyone. I have a 1982 atc 70 i got for "50 bucks". The tank was rusted real bad, and the motor was took all apart for parts. So my buddy had some brand new plastics laying around with a brand new tank, "Got those for 65 bucks". I just woundered if any one made up a 3-wheeler pit bike with the 125 lifan or aftermarket motors post some pics or give me some ideas on what i should do. I want to make something fast so i can rip the thing around and have some fun.

[blue27]

Welcome , sounds like you got a great deal, post some pics.

Yes the Lifan has been installed in a 70, I just finished one up in a 85. Its a Lifan 110 4spd manual clutch with electric start, and it runs awsome. Just working the jetting out and then will get it all painted up. Mounted the Battery on the skidplate and hide it up in the frame and a CRF50 BBR Big Bore pipe this thing rocks. I built this one for a friend so NOW I have to get one for my Suspended 70 now. lol

You should pop over to http://www.glamisdunes.com/invision/...p?showforum=50, it a forum just 70s, but there is a lot of good info here as well.

Good Luck and ask ??????? we have answers (might not be the right one.....but an answer. LOL)

[ke125er]

i have a 83 with a 110 motor and pit bike bars its quite fast to fast for suck a small trike but thats what makes it soo fun lol ill get pics in the monring if u want

[jmsmilin]

Id go with a Lifan, I didnt like the quad we had with a Lifan engine to tell you the truth but some like them and we didnt own it that long, didnt even break it in, they are cheapy though-hence the price...

anyway if you go with a stock Honda 125 on a 70 the sprockets do not match and so you have to run the wrong size chain. It works, lots have done it, but I dotn like it. The lifan sprocket matchs the 70 sprocket, and you dotn have to bore out the hole in the frame where the engine bolts to.

Check out the glamis forums, jsut do a search lots o info on the swaps-here also

70s with suspension are better, let me know if you find one, I want another...

your best bet, just buy my TRX 90 and forget all that work...

[Vealmonkey]

I have put a lifan 4 spd 125 with a manual clutch and a kickstarter into my suspension 70 and converted it over to a pull start with a trx70 side cover and recoil starter. You can modify an atc70 side cover to fit also, it just takes a little more work. The lifan 125 engine is a bolt in. You will have to change a couple of electrical fittings over so all the wires fit together nicely and you can paint, powder coat or chrome the modified side covers to match the other side cover on your engine. I hope to be sending my side cover out to get chromed with a little more work to it. You will probably have to get a different intake manifold so you can clear the stock frame and tank and you will have to run an aftermarket air filter. The lifan 125 engines usually run around $300 dollars give or take with shipping depending upon where you live.

[oemstunters]

Thanks i shaged my seat last night and put my new plastics on it looks sweet. i am going to strip it all down and paint it tonight. and i need to fix or get some new tires.. but i will have to look for a motor.

[crnacnac]

Here's mine with a 125M motor with electric start. I mounted my battery like Blue27 did.

jmsmilin is correct the sprockets/chain do not all match. The front sprocket is a 428, the rear is a 420. You use a 428 chain. But, I've been running mine for the four years with no chain issues. I've done three of these conversion with no problems also.

There is definetly more work in installing the 125M motor verses a Lifan. You can see the front mount attachment point that I made to bolt the front mount to. It needs this mount because this motor is HEAVY. I wasn't building this to be a drag racer so I wasn't concerned with the added weight of the motor, starte and battery. I wanted to keep my 70 "all HONDA"

The pipe I run is a CRF50 from Minigunz.com

Which ever way you go, you won't regret it. I have more fun on my 70 than I do on my Raptor.

[oemstunters]

Thanks that gives me some ideas. Any body else have some ideas to throw at me??

[jmsmilin]

I have put a lifan 4 spd 125 with a manual clutch and a kickstarter into my suspension 70 and converted it over to a pull start with a trx70 side cover and recoil starter. You can modify an atc70 side cover to fit also, it just takes a little more work. The lifan 125 engine is a bolt in. You will have to change a couple of electrical fittings over so all the wires fit together nicely and you can paint, powder coat or chrome the modified side covers to match the other side cover on your engine. I hope to be sending my side cover out to get chromed with a little more work to it. You will probably have to get a different intake manifold so you can clear the stock frame and tank and you will have to run an aftermarket air filter. The lifan 125 engines usually run around $300 dollars give or take with shipping depending upon where you live.

can you post pics and details on the pull start conversion? Im thinking about putting one of those 138cc engines in my TRX90, I heard a few folks had issues with the kicker, and it wouldnt clear anyway, plus no elec start on those...

[hotrod 110]

Why couldn't you just swap the stator plates between the two motors? No wiring problems , you can buy new primary coils , plug and play. The Kitaco inner rotor kit fits import and Honda motors , so why bother with finding a TRX70 donor? You'd have a points system again - with no rev limiter and an easy ignition advance .

[Vealmonkey]

The problem is that not all the plastic wiring terminals match up. You have to buy 2 different wiring termainals than what is supplied, take the wires out of the terminals and put wires in the correct order and plug them back up, done. And it looks very clean. That is really the only wiring problem becuse the lifan I received, come with the new cdi, coil and everything else needed but the 2 correct plastic terminals. So, except for my kill button, all new electrics.

[oemstunters]

I put a stock xr50 motor on and the xr 50 exhaust wont mount anywhere....all i have to do is weld up a mount right...
the motor wasent enough to pull me around like i wanted it to so i bought a lifan 125 motor this morning but the other thing i was woundering was will it fit with out hitting the front tire????? hope it will cause i really dont feel like fabing the frame. but it really woundent be that hard.. any help would be great thanks

[oemstunters]

Can any one help

[Vealmonkey]

The 125 won't hit the tire, but some people have cut their front fender for clearance. Just make sure your front forks aren't bent and the fork stops are in good shape.

[O.S.Triker]

I like that BBR pipe . Will it work on a stock ATC 70 ? Also how loud is it compared to stock ? Thanks