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

[Big G]

Didn't think I'd ever be able to buy a complete trike for under $100. The ad said $75 obo. I offered him $40 and he took it!
Seller said he inherited it from his uncle who passed away last year. It's been sitting in storage since. He didn't know if it ran or not, but I figured at the least I could part it out and make my money back. It has new tires with lots of tread left so I figured I couldn't go wrong. Well when I brought it home I checked and it has spark, so I think I'll have no problems getting it going. I'm sure the carb is gonna need a cleaning, air filter replaced, etc., but all in all should be a decent little trike.
From what I can see so far she'll need new brake levers/cables, seat recovered, and tank cleaned out. I was suprised to see the rear fenders are made of fiberglass - I guess this was what Honda used prior to plastic (?).
I do have a couple questions though that I noticed right away:

- The seat just sits on the rear fender unit. I'm going to get it recovered, and just wondered if it's supposed to fasten to the fender somehow. Or does it just sit on there like that?
- The front brake drum seems to be at an odd angle for mounting the brake cable (see pic). Does anyone know if it should be spun around and secured to the front fork somehow?
- The exhaust has no muffler...only a straight pipe from the engine. Other than being loud and likely the odd backfire, will it harm the engine/valves to run it this way?
- The ignition switch is located on top of the front headlight, which seems like an odd place. I did some quick searching, and it looks there's supposed to be a kill switch on the throttle housing as well(?) The throttle I have has no kill switch on it, and it doesn't have a hole where one would go. Maybe some models didn't have this feature?
- Is there something else I should check or watch for on these trikes? I don't know much about the 90cc's, never owned anything under 200cc.

Thanks in advance for any help :p

*I also include pics of the original warning decals. Thought they were kinda neat...especially the one about the "altitude compensating carb".

[oscarmayer]

There should be a seat pan that bolts to the fender. it uses simular squared headed nut things like the early model 185's did. you will just need to unbolt it and should be good.

BTW, you got a steal of a deal sir!!!! enjoy it!!!

[JasonB]

i want a 40$ 90! damn it! price is right, make it shine!

[Worden18]

Nice find! Good luck on getting it running; let us know when you do :)

[Ghostv2]

Im surprised he didnt give you your money back for gas to get home with a steal like that.

[90guy]

Great Find. As for the Brake drum up front. That isn't a factory 90 option. Looks like it could be off a 185 or something similar. For the kill switch on the throttle housing all 90s had that. So that might also be off the same 185 or similar. As for the straight pipe. I have heard that it is not good for the valves do to all of the back firing it will do. And for anything else. These are awesome little machines!! Haha Keep us posted when you get it running!

[coolpool]

The seat has no pan like you normally see. It consists of a partial pan at the rear with two bolts that protrude through the fender and two metal plates that sit on either side of the seat that also have two bolts. These two plates sit in pockets of the cover and keep the cover down. It's tough to explain. I did up a 78 ATC 90 a few years back and just made a pan out of heavy puck board and bolted it through the fender. I'm in the process of fixing a 1977 ATC 90 right now; they're easy to work on I find.http://www.3wheelerworld.com/showthread.php/159745-Operation-quot-Fugly-quot Yes the fibreglass is factory. I like it because the average joe can repair it with some patience.http://www.3wheelerworld.com/showthread.php/130250-My-First-Attempt-at-a-Fibreglass-Repair?highlight=fibreglass+repair

BTW the reflectors and extended rear grab bar are Canadian only options (maybe Europe too?) You stole that thing; I paid three times that much for "Fugly". PM me if you want to discuss issues you come across.

[Big G]

Thanks for all the help guys. I see now that the front hub/brake drum and thumb throttle came off another model. I guess they only had rear brakes on these things.

Coolpool...

- Could you post up a pic or two of the seat pan on these things. I was trying to visualize your explanation but I'm having a tough time wrapping my head around how the seats supposed to mount to the fender. Looks like I'll have to fabricate something because there's no pan of any kind under the foam on this one.
- The grab bar on mine looks like it sticks out further than "Fugly". Do you know if mine is stock or has it been modified?
- Is there anywhere I should be checking for cracks on the frame of these?
- What's the blue cap on "Fugly" for...you mentioned something about cam chain adjustment hole...Is this something I should be checking on mine?

I'm sure there'll be more questions as I start going through the trike...like I said this is unchartered territory for me :)

Oh and, I know this is a long-shot, but if you have an exhaust for these things you want to sell let me know. I'd be willing to pay a good price for it :D

[coolpool]

Here you go Big G. There's no pan at all;just the partial at the rear and the two plates that fit in pockets that hang down the sides of the fender. You should have two holes just above the "Altitude Adjusting" sticker and the same on the other side. Hope the pics explain better. The finished seat is a US90 one so the rear pan is a little different, but they have the same type of bolt up. It appears to me that all your hardware might be under that seat already. They rust out fairly easily so who knows? Your rear grab bar is the same except someone welded on a trailer hitch or flag mount. If the frame isn't rusted out it's probably good. I don't know of any weak spots that routinely crack, except maybe around the grab bar mounts. The blue plug is not supposed to be there. The PO lost the cam chain adjustment cap and stuck that in instead. Sorry, no spare exhausts.

[kb0nly]

These frames always crack at the seat/fender release lever, right in the middle of the frame. If you got damage thats where it will be i guarantee it. The 90, 110, and 125M, all suffer from that problem. Jump it hard a few times and it cracks through the weakest point in the middle due to those long oval holes the seat/fender release rod moves in.

[Big G]

Thanks CP...that helps alot! I took a closer look at mine, and you're right, the remnants of the partial pan at the rear are there. I would have never recoginzed it though as it's rusted pretty bad. Looks like I'll be manufacturing something to hold the seat down once I get it reupholstered. As for the exhaust I'll just weld on a muffler off another 70cc - 110cc dirtbike/ATV. I found a stock one on eBay, but it will cost me $130. Also, do you know if these trikes were manufactured with only a rear brake?

Thanks again for posting the pics and all your help!

[Big G]

These frames always crack at the seat/fender release lever, right in the middle of the frame. If you got damage thats where it will be i guarantee it. The 90, 110, and 125M, all suffer from that problem. Jump it hard a few times and it cracks through the weakest point in the middle due to those long oval holes the seat/fender release rod moves in.

Thanks kb0nly...I checked mine and she's still solid! :p

[90guy]

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

[kb0nly]

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.

[90guy]

I'm not certain but I'm going to say 185s front brake drum it looks like. I'm wonder if they didnt wedge it or just let it sit on it? Idk lol nits interesting! Haha

[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. :p

[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?

175873

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.

175874

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.