School me on atc70 motor swaps...what fits?

[Nick_R_23]

Ive decided that I dont have the time or money to fix my 84 200x, and since I have an 86 200x, I am going to sell the 84 and use the $$ to finish my 70 that Ive always wanted. The engine thats in it 'runs'. Mostly when it feels like it. I know for a fact that it needs the ignition gone through, and the carb. Its hard to get started and when it finally does itll go for a bit then die, and wont run again unless it sits for a while. Is it worth fixing this engine, or would I be better off buying a Lifan or other Honda pitbike engine (XR70, etc)?

The engine I have would at least need points, carb kit or most likely a whole new carb, and probably other things (filter, maybe timing chain, which would lead to gasket kit, etc). Im not really a fan of points motors, and a new motor would basicly be bolt in and go, no rebuilding anything, which is why Im leaning towards dropping a new engine in.

I dont really care what the motors for, whether its a Lifan engine or a honda pit bike motor, but if I go this route the motor must NOT have electric start, and must have a clutch (no semi autos).

The questions I have if I dropped in a new motor are:

1. What engines could I put in that would require little to no mods? I think that the 125cc+ motors hit the front fender, would the 110s do this too? I also heard that front motor mount mods are necessary on some engines?

2. What are my options for starting? Does someone make an engine with pull start or forward kick, or is there a way it put it on? I do not want electric start.

3. Will the new engine's carb hit anything, and will I be able to use my stock airbox? Will I have to use the original intake for carb clearance?

4. Are there any other issues I would need to address? Like wiring, exhaust, throttle cable, or other?

-Nick

[Vealmonkey]

You have hit on a lengthy subject. You can add pullstart to a kick start model if you use a trx70 side cover and either an atc70 recoil starter and cage or a trx 70 recoil and cage, but you must use the atc cage with the atc recoil or the trx cage with the trx recoil. I know of no lifan or other engines that are forward kickstarter other than a modded 200x engine or a insanely modded 250r engine and people have done those swaps. A trx90 engine will fit and any engine that fits in a z50 series machine will fit. An atc90/110 engine will fit, but you need to get a special cradle for the engine for it to work. With most lifans and the stock atc70 frame you need to get a special adapter for the carb to work. The front fork and the fender will be really close and can rub, but alot of that depends on the straightness of the frame and the straightness of the front forks. Some people add 3 inches to the frame between the neck and the seat area and then move the front tank rubber mounts. I think the largest engine that is a straight bolt in the gpx 160 or the gpx177. If you used and sl70 or xl70 and wanted to keep it all honda and still get the kickstart and manual clutch that you can get big bore and stroker kits and go at least 110cc and I believe as high as 124. Different engines have different shift patterns so you really need to be careful if you want a certain shift patter. Gears are generally a 4 speed and some engines use an oil cooler and some don't so you may have to find a mounting point for the oil cooler. You will probably want to use wheel spacers to clear the kicker. And you might have to buy fiberglass fenders and make a spot in the fenders to clear the kicker also. There is a guy on ebay that is offering fiberglass stock fenders and my buddy blue27 is having the A+ fiberglass fenders being made a mold of, so there should be a low profile racing type alternate soon. Good luck with whatever you choose and have fun. I hope this info has helped.

[Nick_R_23]

I think for now Im gonna throw some new points/condensor on it and a carb kit, then try an ebay carb if the kit doesnt help. If none of this works Ill go with a new motor then.

Whats the difference between the ATC and TRX sidecover? Is there a difference that doesnt let the ATC cover work? What kind of cradle does the 90/110 engine need? I havent heard of this, only that the front motor mount needs some kind of modification. With lifans, what kind of carb adapter would I need? Can I use the stock intake or does it not fit? If I do go with a Lifan I want a 1 down 3 up pattern. Dont want an oil cooler though. Does anyone have a 70 that they have a kick start motor in that they could post pics of the clearance? Im missing the rear seat bracket so this could be a good opportunity to make a hinged braket and have flip fenders. Has anyone done this before?

-Nick

[Vealmonkey]

The TRX sidecover has a "plug" in it that if removed, will let you see the timing marks on the flywheel of an electronic ignition engine. Also the cage that attaches to the flywheel is atc or trx specific. If you want a pull start conversion, you have to drill and tap 4 holes into the flywheel and you have to machine some material from the recoil starting cage or both the cage and the flywheel so the cage will fit, no big deal though. As for the cradle, if you find edogs thread on the gpx177 build, it will show pictures of the cradle. As for the carb fitting, the carb usually hits the stock frame with the stock lifan intake, the adapter or the different intake, turns the carb away from the frame allowing everything to clear. You will have to do a "search" for a lifan in an atc70 to see how the clearance is, but it's no big deal really. There have been many of these swaps made. If you go to Glamisdunes.com and look for their atc70 section, these guys can do these swaps in their sleep. Also several have put the atc90/110 engines in their trikes and have attached the front engine mounts even. There have been a couple people that have made tilting mechanisms for their rear fenders. They seem to be a little involved, but looked very sanitary. There was a set up done all out of aluminum that was super clean if you go to the glamis dunes website under the 70 section and do a search. Good luck with whatever you decide to do. I hope this helps.

[oneroom42]

let me know how you make out with your original motor after the carb and stuff. my motor was doing the same thing so i picked up a used one on ebay for the time being. my plans are to redo the other motor with an 88cc kit.

[Nick_R_23]

I ended up saving the engine I had. I figured points, condensor, and a carb kit was cheaper in the long run if thats all the motor needed. I got it all put on and it fired up and purred first pull. That sucker can really hold a wheelie!! I havent really had time to ride it, I need to get out and clean out the tank real well, you can just see the lines are full of crap from sitting. Other then that it runs great now.

-Nick

[Vealmonkey]

Congrats, I enjoy happy endings! How about some pictures.

[Nick_R_23]

In this thread, I have no idea why I made a different one.

http://www.3wheelerworldforums.com/s...ad.php?t=90941

On a side note, does anyone have pics of an all red 70? I.E. one with a red seat cover? I know where I can get a few NOS aftermarket ones pretty cheap I think. Never seen one with a red seat cover before.

-Nick

[saleen_n_around]

Some good info here.......kewl!

[Vealmonkey]

Very nice trike. You may just want to update that engine with that 88cc kit though.