picked up this '77 ATC 90 last night...for 40 bucks!!! Some questions too :)

[Big G]

Yes these old guys only came from factory with only rear brakes...

Okay, that's kinda what I figured...thanks 90guy!

[Big G]

I have always thought about adapting some front brakes to one though for better stopping power. What do you think that brake and wheel on his is off of? I wonder did they swap the forks as well because otherwise there wouldn't be anything for the brake assembly to key into so it didn't rotate.

EDIT....

I took another look at his pictures. Thats a 125M front wheel/hub/brake assembly. The notch where the pin of the forks is supposed to go is ahead of the forks and not sitting right. Obviously it must have the wrong forks or they installed it wrong.

Is there a metal pin sticking out on the inside of the fork on that side? That should be in the notch of the brake assembly.

Good sleuthing kb0nly and 90guy!...There is no metal pin sticking out on the inside of the fork to receive that notch on the brake assembly. This leads me to believe the front forks are original, since the ATC90 didn't have front brakes, and therefore no pin on the inside of the fork! The trike did come with 3 spare rim/hub assemblies with old rotted out tires on them - from what I can tell they're the original 2 original rear wheels and 1 original front with axle. I asked the guy if they were the originals, but he didn't know for sure. Regardless, from reading yours and 90guy's posts it pretty much confirms the originals where swapped off. Well I guess the one nice thing is that if ever I want front brakes I have all the "guts" right there. All I would need to do is weld a pin or tab to the inside of the fork on the brake side to receive that brake drum notch and prevent the brake assembly from spinning when the brake is applied.

Anyways, thanks guys for the responses and helping me out on this one so far.

[kb0nly]

Yep, wouldn't be too hard! Thinking if i can come across a 125M front assembly i might do the same. All you would really need to do is quite simple. Here is how i am thinking of doing it. Pull the front axle, remove the wheel from the axle to get the wheel and tire out of the way, reinstall the axle, line up the notch with the fork tube, mark the location the pin is needed, remove the axle again, drill a hole to accept a piece of metal rod, just through the inner side of the fork tube, then switch to a smaller bit and drill a small hole through the outside wall of the fork tube. Then cut a piece of rod and slide it in, plug weld it on the outside and then weld around it on the inside. Would be plenty strong. I suppose you could just surface weld on a chunk too, but i like to reinforce things that i fabricate and thats the strongest way i could see doing it.

Of course if you got a hold of a cheap set of 125M forks you could just swap them too, but i think modifying is easier and cheaper.

[Big G]

Well I finally got around to trying to start this ATC90 I bought a few weeks ago. I knew the carb would be a mess, but I didn't expect it to be this bad. Anyone have any suggestions on how to tackle this carb rebuild. I'll be buying a carb kit, but need to at least clean the worst off first. The fuel intake ports on the carb seem to be plugged with a black tar sludge, and as you can see, the rest has a solid coating of white varnish. I'm thinking it should soak in something for a while?



Well once I realized that the stock carb was out of the question for initial start-up, I threw on a spare Chinese carb that I had from a small quad. A couple pulls and she fired up! Not that I expected it wouldn't...after all, she's a Honda! I bungee'd a plastic gas tank on for now (the original tank has rust inside and needs the vinegar treatment), and my 7 year old son ended up riding it around for quite a while.



Anyways, just thought I'd let you guys know I got it running, and now that I know it runs I'm going to start fixing the other things that need attention such as brakes, chain tension, muffler, tank clean, and seat.

[kb0nly]

She's a runner... Of course she is, its a HONDA!! LOL

Looks like that chin-carb you tossed on there for testing fit pretty good actually. Maybe just get it tuned in and leave it..... ??

As for the original carb, i would get some carb dip, remove all the rubber parts and everything down to the aluminum body, this includes the jets and such, toss it in the can of carb dip and put the lid on and go away a few days. This new stuff they sell now days doesn't do the job the old stuff did. The old stuff back in the day you could melt an aluminum carb into goo in a few hours. No joke.. This new stuff your lucky if it takes the varnish off in three days. The float can be cleaned up with a scotch brite pad or a some fine steel wool.

Your other choices, boil it. No kidding.. Again strip it down then toss it in. I have done this outside with a little camp stove and a pot of water, keep adding water as it boils off to keep the carb covered in the pot and just keep it at a rolling boil for a while, use a set of BBQ tongs to pull it out now and then and check it. I have boiled crap out of carbs before if the carb dip wasnt available or didnt get the job done. Follow it up with some carb cleaner and the air compressor to blow it out.

[coolpool]

Great to see it runs! As for the carb, I seen that Mattdragontamer has used CLR with good results. In my experience, most carbs can be salvaged with a little elbow grease and attention to detail. I've only ever had to buy a rebuild kit for one carb that had the float damaged.

[Big G]

Those are both really good ideas that I never thought of before. I called the local auto parts stores, and they want 60 bucks for a gallon of carb dip, so I'm going to try getting the worst of it off with CLR first, then boil it.

Thanks again for the tips!

[Jeepermc]

I put suspension 185S forks and brake on one of my 77 90's and the other just got the suspended forks. It helps, but they're still hardtails....Little bit of grinding and adding steering stops and the forks bolt on and operate as they should.

Correction- Looking back it looks like I used 200S front suspension and brake.