Bringing in my '74 ATC 90......What should I do to it?

[oddy_fever]

Now that the snow is here, it is time to start work on the ATC 90. What suggestions do you have?

My thought is to bring it in and do a complete tear-down. I have no history on the trike. I don't even know what the inside of the engine looks like.

I have a ton of questions, and will post them as time goes on. I have hopes for suggestions right now. Not to concerned about an accurate restore. I will be riding this when it is running.

I guess where I am going is if this were your trike what would you do to make it the baddest little 90 around?

Sorry for the length of the post and I am eagerly awaiting your responses.

Here are some pics of it..... http://www.3wheelerworldforums.com/showthread.php?t=40106

Thanks,

CJ

[danteross77]

nice bike, I think you are going to need to break it down, it will make changing those bent forks easier. The motor is easy, my 9 year old and I just rebuilt his 1979 110, should not be that different, we actually decided to say the heck with original and put a 1982 motor in it with a cdi unit so we would not have to deal with the points. we also out a 250r aluminum front rim with atc 70 spacers and aluminum rear rims to match, he has a growth problem and he was bored with his atc 70, so I put the narrower tire because it is lighter and easier for him to handle. I would see if it will crank, start up, get a parts list together and then tear it down, no sense in replacing expensive parts if you don't need to.

[Vealmonkey]

How crazy do you want to get? You could find an old aftermarket frame. You will probably want to get a 1 piece rear axle instead of the multipiece axle you have. Then you probably want to get better wheels and tires but the wheels you have are special because your year is meant to have tthe balloon tires and the wheels you have are special to put regular tires on the balloon tire hubs. If you change the front forks, go to a later style fork and hub set up. Look into putting at least a 110 carb and intake manifold and getting a better exhaust, but good luck cause the exhaust is meant to pass through your frame and those are hard to find aftermarket. Your going to have a hard time cause the year of your trike. Try finding an aftermarket frame on ebay or on here and go from there. Some aftermarket frames are Nicholson, Bandito and there are many others, you just have to find one. That is your best bet. There are always cams to go with the 110 carb and exhaust and if you bore your cases out you could always go with a bigger piston and a stroker rod, depends on your budget. But definitely look for a neat aftermarket frame. And if you want to sell those wheels, let me know cause I have a 1973 and it only has some kind of goofy adaptors and your wheels look much nicer.

[oddy_fever]

Thanks guys. I would love an aftermarket frame. This one appears to have been modified. It will take some welding to make it decent again. Someone decided to add a rear trailer hitch and weld it solid to the frame!!

I might be interested in parting with the wheels.

I don't want to invest a ton of money, but I don't plan on doing it on the cheap either.

Are the one piece axels hard to come by? Are they aftermarket or just off a specific year ATC 90?

[MTS]

Start with a complete tear down, now depending how much coin you have to spend, i would start with new points, piston/bore/ check valves-regride or replce, if you wana get a lil wilder you can get a bigger bore higher compression piston and a stroker crank from www.powroll.com, also i would go with a new set of clutch pads, check the front primary sprocket, i would replace unless its new becuse you allredy have the3 motor apart and you have to tear off a side cover to get to the sprocket...so easirt to do now, id leave the rims and tires, they work great on atc90's( i know i had one) also spec out the cam and check rockers for wear, www.webcamshafts.com sells a performace cam for them, you can find a performance pipe from DG performance an airfilter from K&N and of course reject the bike accordingly.

[danteross77]

if you need a one piecr axle, i have an extra one from my recent rebuilt it is off of a stock 1980 110, no sure if it will work though.

[Vealmonkey]

The axles from 1975 and later are 1 piece. I do not know if the bearings from 74 and earlier are different from the bearings from 75 and later, but I would look there first. Any hubs, 3 or 4 bolt will fit onto the 1 piece axles, you could run 200x wheels if you want. Also look for a 75 and later front axle. They have a 3x100 bolt pattern up to 82 and a 4 bolt pattern 83 and later. If you want front brakes, you could get a front end off a 185s and get a drum front brake or you could even use a 200x front end, they will bolt onto a stock honda frame or an aftermarket frame and you would have suspension and a front disc brake. The aftermarket frames are usually longer and can hold a 90 or 110 engine. Not sure about the 125. Before you do any changes, do alot of research and ask questions, it will save you alot of money and heartache. Make sure you have a good shop manual, Honda is the best of course, but the others will do ok in a pinch. Take your time and have fun. You can work on the engine first while trying to find another frame. Post a wanted thread in the other section on here and see if anyone has a frame for sale. People might have some 90 or 110 parts also. Blown 331 just bought a crap load of bikes and said he had some 90 and 110 parts. I think there is a 110 with an aftermarket frame in florida for sale right now, I don't remember the sale number but I'll look again for you. I remember reading somewhere that you had to bore out 90 cases to put in a 110 cylinder but I don't know how accurate that information is. Do your research and ask questions, take your time and have fun, That's what matters.