How old or rare is that US90 or that ATC110

[oldcodger]

Hello again "ccolpool" and "HairyJR". Coolpool, I see you have two 1970/71 US 90s listed on your response page, are you saying neither of those gas tanks has the indented area where the warning decal goes? I am critical of the blue paint on the Honda museum piece because it was recently restored by an american company (shop) and they chose to paint it that way because I think they thought it looked "Nicer". I can not find any evidence yet that early units were ever painted that way! Hence the interest in everybody's original early US90 painted frames and serial numbers! The heal protectors (the rubber edging) on the front of the rear fenders on my US90 were attached with rubber? rivets originally, but only two are remaining with the balance of six being replaced with screws and nuts. I will try to remember to attach a picture of the axle for you. Hairy, I am able to view pictures again, have no idea what was causing the problem. Your pictures are enlightening! The blue frame painting is as mine, stops roughly at the tank mounts. I now can see what you describe as the "steel loop heel guards", could they have been "carrying handles" when the unit was disassembled? Wow, that is an early frame serial number! These photos of yours when you purchased them before any clean up are impressive, starting to understand some of your other comments. The belly pan/skid plate is very clear. Was it used though out the US/ATC 90 lifetime? Your comment about removing the right side wheel and spacer and sliding the axle to the left might suggest that the left wheel did not have to be removed in order to disassemble for moving/carting. It might also explain the lack of needing a spacer on the left. At this point I must admit that I have not removed or broken down my rear axle, so I am ignorant of it's design. I have been reluctant in part because I don't know how to remove the rubber axle nut protectors and didn't want to destroy them. Somewhere I recall reading that the heel protectors were glued on in the beginning which might be the reason for no holes on your early US90, But a fiberglass replacement might also be supplied without holes for ease of installation and cost reasons.

[oldcodger]

OK, sorry to drop this on you now, but a trip to the swap meet this morning has now resulted in an offer. Update: the offer has evaporated without much input from the viewing audience so I see no point in making it part of this history. Hopefully more information will come in the future!

[HairyJR]

“oldcodger” I don’t believe the “steel heel loops” on the foot pegs are “carrying handles” as they only lock into place at the riding position, they fold under the frame in the released position. Wasn’t sure if you knew how the rear axle disassembled for removal. If you haven’t tried yet axle could be frozen “rusted” in drive sleeve, may need to soak with penetrating oil. Can’t speak for all years but all US90’s thru ’83 ATC 110’s had a bottom belly pan/skid plate of some type. The rubber axle nut protectors pop onto a large thick flat washer, if their still pliable rubber “soft” just pull and twist.

As for selling them you have no sentimental attachment which would influence price, you know your investment cost, but the offer seems real fair. With balloon tires price would be higher.

"HJ"

[oldcodger]

Thanks again for the inputs "HairyJR". I have gone back and reread the earlier postings with the information learned so far and a couple of questions arise. In one of the early pictures posted by "ps2fixer" I seem to be looking at an axle with a spacer assembly like mine siting in a wheel on a wooden pallet. Is that an early dismountable axle system? If you were to say yes, why then is there a sproket and chain cover, wouldn't all that stay on the trike with just the axle passing through it all as it was slid out? In a posting by Joseph farrow you are showing an early serial number in the 1035xx range. Can you tell us where the green paint stops on the frame? is it near the tank mounts? Does that "survivor" have any other of the details we have been discussing?
Hairy, not sure why you believe the skid plate is assembled differently on the Honda brocure, it looks the same to me, but then that's why I'm here asking the questions! I am feeling particularly stupid at the moment because I went out and looked at my two trikes and the US90 has a belly pan in place! Don't know how I missed that!

Regarding the offer, just waiting to see if it's all talk. I have been watching several eBay offerings and am encourged to see more than just two individuals biding each other up.

[HairyJR]

OK yes the picture “ps2fixer” shows the axle removed with the “wheel shaft” (what the manual calls it) assembly still installed. For normal disassembly to transport you remove the right side axle nut, wheel/hub, and distance collar (sleeve). DO NOT remove the lock nut next to the brake drum. Now slide left side wheel/axle assembly out of “wheel shaft” off the four drive pins. May be stuck or rusted in place, lightly tap with . Chain guard, sprocket, and brake drum assemblies remain in place.
I’m old and relied on my memory having looked at the original brochure, thought I was looking down thru the holes instead of looking up, installed as all others. As far as those listed on ebay, blue one just listed for @ $4000, it and several other US models have been listed several times in the last couple months and haven’t sold, relisted……

"HJ"

[oldcodger]

I figured it might be time to try and sumerize the information we have gathered so far that would help identify a first year US90 Honda from other later years. A few questionable inputs might result in a little more inputs in general!
* Lets start by saying there is no such thing as a 1969 US90. All that is known so far is that Honda started selling their 1970 model year in late 1969 through to the end of 1970.
Starting with frame serial Number US90-100,122 and ending theroletly with frame NumberUS90- 200,000, which was probably never used. Original motors schould bear numbers within
100 digits of their frame numbers. Later units have same frame and engine numbers starting when?
* The first year color was Aquarius blue. At some serial number they added a red? a green? and a yellow?
* The gas tank has screw on chrome "honda" tank badges.
* The gas tank has a rectangular relief to the rear of the cap where the "off road only" decal is applied into.
* The kill switch has two positions "on" or "off" and points to left. Not the three position of later units, "off" "on" "off" and pointing foward.
* The handle bars have a locking lever that allows the bars to be turned for transport.
* No ears on fork tubes to carry a headlight, only chrome accesorie brackets avaliable for optional headlight, although all units posses wiring for front and rear lights, but not stop light.
* Front fender made of steel, not moulded plastic.
* Rear fender assembly made of fiberglass, not moulded plastic.
* Rear axle made to be removable for transport by removing right wheel and spacer and sliding axle with drive plate clear out left side of sprocket/drive assembly. No spacer used on
left side.
* Front engine mount is part of the frame sheet metal, not removable.
* Color paint ends in area of gas tank mounts, does not extend to include front engine mount.
* first variation of footpegs have steel hoop heal protectors and no rubber heal protectors on fender.
* 2nd variation in first year have rubber heal protectors attached to rear fender with pull through rubber rivits, eight total, not screws and nuts.
* Foot pegs fold in horizontally when latch mechanism is triggered, does not use wing nuts and studs.
* Small end of foot peg is chrome plated.
* Carburetor gas inlets are parallel and float cover screws enter from top.
* Carburetor has push/pull altitude control and unprotected choke lever.
* Carburetor fuel bowl drain is to front.
* Front and rear tires are difficult to come by, but were made for at least a ten year period, so may or may not be original and/or not nearly as old as the trike they are on.
* Tires mount to hubs using small triangular three bolt pattern, later units used larger triangular pattern.
* Brake handle on bars has wire clip to "set" rear brake, and white plastic plug in mirror mount. Hand brake control unit was used on other Honda motorcycle models using rear view
mirrors at the time.
* Rope start handle has Honda's stylized "H", large flange, and rubber plug, in contrast to later smaller flange design.
* Grab rail allows for wider optional tail light assembly, won't accept later narower tailight assembly without modification.
* Grab rail structure is of slightly "beafer" construction.
* Throttle controll was made of plastic, waranty replacement was metal.
* No tool box, and no provision (threaded holes) in frame for one, only bracket for tire pump (rare).
* Gas cap had "on off" position so gas did not leak out with bike laying on side during transport.
* Air filter connector tube uses wire spring clip on front and screw band on rear.
* Gas valve lever "points" to position, "off, run, res" instead of lever itself becoming "pointer" as later.
* No decals used on front or rear fender.

If creditable additional inputs are submitted I will try and edit this starting list.

So thats my story and I'm sticking to it

[Joseph Farrow]

Good Stuff!

I have to agree with almost everything you have with exception to a few things. I am no expert, just working off of observations.

* Gas cap had on off position so gas did not leak out with bike laying on side during transport
Not sure on this one. IIRC the on off type gas cap did not show up until the 1979 ATC110.



* No decals used on front or rear fender
I know the 70-71 US 90 had a fender decal with "Honda ATC90" on the Right hand side on the rear fenders.



* Rear axle made to be removable for transport by removing right wheel and spacer and sliding axle with drive plate clear out left side of sprocket/drive assembly. No spacer used on left side
I really think there were tubes on both sides of the axle.





Great info. There are experts out there. Also if you could find an original Honda shop manual or micropfish it would answer a lot of questions.

[oldcodger]

Hi "Joseph" thanks for the response again.

With regards to:* Gas cap had on off position so gas did not leak out with bike laying on side during transport.
I am working from the assumption that there had to be some way to stop the gas from leaking from the tank when laid over in the trunk of your car unless the tank was completely removed from the frame and the carburetor, messy and complicated! Regarding the use on a ATC110, I don't see the purpose unless you consider the "front wheel up" storage position used by some in a crowded pickup or trailer, and then it points to the same requirement.

With regards to:* No decals used on front or rear fender.
I am under the assumption that Honda was calling the unit a US90, and not an ATC90 until some time later, so it doe's not seem reasonable that they were using decals that said "ATC90" in the beginning. Your photo of the decal show a very unusual rear fender with metal rivets along it's complete outer edge, quite a divergence from anything else Honda ever made on trikes or motorcycles, so I am doubting it is an original fender without rework.

With regards to :* Rear axle made to be removable for transport by removing right wheel and spacer and sliding axle with drive plate clear out left side of sprocket/drive assembly. No spacer used on left side.
The left axle in the picture supplied appears to be a solid weldment, not a spacer! Is it actually a spacer?

I must admit that sometimes I am controlled by "well it should be that way, even if it isn't" syndrome, but I am trying to resist! Come on people let's have some inputs!

[coolpool]

As per Josephs observations, this synopsis was taken from my original US90 Parts Manual. The left axle tube is on page 39, item 3-1 part number 42313-918-020, PIPE, rear axle distance, the right axle tube is item 3, part number 42313-918-010 Superseded by 42313-918-020, the HONDA ATC90 right rear fender emblem is listed on page 30, item 7, part number 87506-918-000, EMBLEM, body cover. Even though the manual is dated 1971, all pictures are of the early model US90's showing all foot peg configurations available and the indented tank for the emblem. Hope that clarifies some.

As for transporting, the instructions in the "Riding the Honda ATC" manual dated 1971, list two ways to deal with the fuel for transporting: 1. Drain all gas through the carburetor drain until empty, or 2. Drain carb, seal off the tank with the optional fuel tank cap.

[HairyJR]

As per Josephs observations, this synopsis was taken from my original US90 Parts Manual. The left axle tube is on page 39, item 3-1 part number 42313-918-020, PIPE, rear axle distance, the right axle tube is item 3, part number 42313-918-010 Superseded by 42313-918-020, the HONDA ATC90 right rear fender emblem is listed on page 30, item 7, part number 87506-918-000, EMBLEM, body cover. Even though the manual is dated 1971, all pictures are of the early model US90's showing all foot peg configurations available and the indented tank for the emblem.

"coolpool" never seen a early "US90 Parts Manual" what are the chances of getting a copy? I have the "Honda US90 Shop Manual" 1970 printed version. Would be nice to know all the accessory options that where available.

"HJ"

[Joseph Farrow]

If someone can convert either or both into a pdf file I would surly take a copy.

[oldcodger]

"HairyJR", if you have a a 1970 printed shop manual why can't you clarify some of these remarks? Isn't it possible for you to take a picture of the rear axle assembly as shown in your manual, and post it here? If you were to examine the photos in the manual (I'm guessing there are photos) are you liable to see "the presence or lack of" the decal in question on the right rear fender? Maybe qlimpse a gas cap?

"coolpool" the same sort of request goes out too you. You are trying to support your "synopsis" without allowing us to see first hand the pages you are taking the information from even though you could easily take pictures of those pages and post them here. The information gets more blurry when you finish by saying the parts manual was printed sometime in 1971, not 1970. To me that means the information could be from a period two years later. Also, someone earlier said the "on off" gas cap was first introduced on the ATC110 in 1979 but you are mentioning an "optional fuel tank cap" being described in your 1971 manual? Any pictures?

"joseph farrow" You are showing a left axle in your photo that looks like it is a solid weldment and not a spacer, which is it?

Ditto on copies of those manuals and parts list!

[coolpool]

HJ, joseph and oldcodger I'd gladly get pics of my reference material. HJ, I have the US90 Shop Manual and it's lacking in information for sure. My parts manual has a pretty stiff spine and the pages are brittle; so laying open the pages for scans isn't an option at the moment. I can very well see a parts manual coming out after the fact. The print date doesn't mean creation date. This was different technology back then and maybe the drafts weren't ready when the machines were sold. As I said, all pics are of the early version.

[HairyJR]

First of all I’m no expect with computers or programs, but I can scan a couple pages maybe to show from the manual its 33 pages. Believe me when I say “Honda’s” attempt at top quality shop manuals back then where fairly basic, no engine repairs noted either reference you to a CT90 Shop Manual. Not one picture of the complete bike as an overview, all close ups of the particular subject for explanation therefore no seat/fender view of any decal or rubber heal guards. Page 20 shows no “on/off” gas cap although I know it was available on other Honda models such as ’68 Z50A Mini Trail’s and newer as I have taken the cap from my ’72 Z50K3 and used it. Frame neck only painted to just behind the gas tank rubber mounts. Could only find two pic’s of axle left side and looks to be no spacer used as the 4 drive bolt hub is angle cut and pressed on the axle and appears to look like the smaller shaft diameter than later models with sleeve/spacer. Having said that those parts being new the metal colors could blend well at the joint and after looking at my early axle shaft pic’s you can see the different metal discoloration. Sleeve is rosette welded next to the outer splines keeping it from being removed. Last page 33 showing wiring diagram lists headlight and taillight as optional parts. Did find one picture of the grab bar (carry pipe) with no taillight installed and of course no headlight pictured anywhere.



couple pic's of my early rear axle


"HJ"

[coolpool]

OK here's some pics of my resources. HJ, I do have the manual you posted pics of; definitely leaves a lot to be desired. The intstructions on "How to Transport the ATC" are in the Riding Instruction book. I know the dates seem off but the pics are definitely of a early model. I am starting to believe that there was a very early version of the left rear axle without a tube after seeing the off set weld. Interesting