1970 US 90 project

[86trizinger]

I just got a 1970 US 90 Parrot green for in trade for my LEM dirt bike.. Its gonna need some work to get it going the way I want.. but looks great for a 39 yr old bike. Its gonna be a good project for my 2 boys to learn on.

No frame rust at all.. maybe a light spot of surface rust here or there where the paint scratched of. Paint is still shiny!!!.. Some of the stickers are still intact.
Rear fiberglass fender has no cracks at all. Front fender had some cracks in the metal.. So for the time being I will drill the ends of the cracks and then carefully weld them back together.

The engine supposedly has a rebuild job .. I've heard that one before. But the engine does have all new screw ands gaskets so that could be true I guess.

The gas tank has seen better days. The tank was Kreemed and looked awful inside because they didn't clean it out before they did it. I am going today to get a kit and redo it all again... Then I will try and get the engine up and running and take it for a spin before we start rebuilding it.

I need a few things for it.
Front headlight
Front Tire

Any pointers or upgrades you have will be greatly appreciated.. New to rebuilding a trike so its a learning process.



I will post pics later today or tomorrow.

[Vealmonkey]

Congrats, now the fun begins. In a few weeks, we can have it to the point where nothing is original on it! LOL I can hook you up with all the fun stuff.

[86trizinger]

http://farm4.static.flickr.com/3345/3549581654_062191ba18.jpg?v=0
http://farm3.static.flickr.com/2477/3549581990_b4b57fbd4a.jpg?v=0 http://farm4.static.flickr.com/3297/3548773915_f95de1431a.jpg?v=0

[86trizinger]

The right side will not show up for some reason.

[MonroeMike]

That's better looking than the few I've have seen on CL in my area.

[Vealmonkey]

I think you will have to end up reducing your pictures down in size. I use a place called online image resizer. It's looking good so far. I would like to see how your tires and rims are on there though. A nice start to be sure.

[86trizinger]

Yeah I just realized... The last pic file size is 611KB... the others are 580.. So i guess the cut off is right around 600KB.. I will reduce the file size in the future pictures. I have photoshop so that isn't an issue.

WHat do you want me to take a pic of exactly.. not sure what you mean by how the wheels are on there.. This trike is new to me.. I am just learning about it.

[bandito90]

Very nice 90!

[Vealmonkey]

The US90s used the high floatation tires. Not like the later model 90 tires. The axles front and rear used a very tiny 3 bolt pattern. Generally to run later model wheels and tires you either have to use adapters, and there are several different kinds or you have to change out your axles. If your axle is sticking out through the center of the wheel a couple inches, then you have adapters. If you change out your rear axle and brake drum to a later model atc90 axle and drum and the front axle too, you will save yourself alot of heartache. Also it is very east to put a headlight and taillight on your trike, in fact your wiring harness should already have the wires in place. If you are not worried about keeping the trike original, then it will be easy to fix up and do alot to make it more user and wallet friendly. If you want to keep it original, it will be a little tougher and more expensive. I just was interested in how original the trike is and what is there to work with parts wise.

[86trizinger]

Just checked.. There appears to be adapters on it to a wider 3 bolt pattern . There is a ton of new bolts on this I just realized... Looks like someone was rebuilding it and stopped.

As for the Head light and tail light all the wiring is right there.. What years interchange on this to fit the stock location.

As far as restoring goes.. I don't really think I have the money to fully restore it to factory.. But I am going to try and keep the older look to it though.. Just a little that is... Definitely some performance upgrades... I want to have fun on it with my kids... When they are older then I will fully restore it to pass it on to them.

I want it to be fun and reliable not just for show.. So if anyone has any suggestions or parts for me please let me know.

[Vealmonkey]

Well as far as the headlight, any round atc90/110 headlight with the switch on the headlight bucket will work. The correct one would be a matching color and there is one on ebay right now for $70, but it is just the shell. If you go to a later model atc90 grab bar, then you can use the cheaper tail light or you can use the 71-74 grab bar and use a slightly more expensive tail light and no one but a real conniseur of the old atc90s would know the difference. The mounts for the 1970 taillight are very rare-expensive. Also the factory correct headlight mounts for the 70 atc90 are rare and expensive, but you can use a universal headlight mount which works just fine and once again, very few people will know the difference. Personall, when it comes to the front and rear axles and the adapters, I prefer to use the later model axles and wheels. You will probably never have a problem with the adapters, but I prefer the security of the later model stock parts myself and I think it makes the trike look more finished. Also if you use the atc110 intake and carb, you do pick up a little performance compared to the stock 90 parts. A DG exhaust is a little louder than the stock exhaust, but I would save your stock exhaust and enjoy the added performance of the DG muffler. Also with a bigger carb and better exhaust, you will need a freer flowing air filter so a UNI or K&N is a nice addition and pretty much a period performance part. If you go to the later model axles, you have a wider range of wheels, including polished aluminum and your tires are a little more open. The only minus is that the tires are your suspension, so your tire choices are slightly limited unless you don't mind a bumpier ride. Try and save that tank if you can, the logo'ed tanks can be a little costly. You can use a plastic aftermarket tank if need be, but don't get rid of the stocker.

[86trizinger]

Stock tank is filled with acetone and sheet rock screws.. 90% of the Kreem is out of it.. Shaking it with screws should get rid of the rest of it.

Tank had a few pin holes that were solder from the previous owner. Only a very small leak.. I don't know if I should take the solder out and weld the holes or not.

I also found an air leak at the carb.. Unless that is supposed to be like that where the carb meets the intake. Is this a stock CARB?
http://farm4.static.flickr.com/3325/3550144812_c0bda23f5c.jpg?v=0

Also it has a brand new air box on it already. As far as the engine goes.. I pulled the covers for the valve adjustment.. Inside of the head looks brand new.. still shiny aluminum.

http://farm4.static.flickr.com/3609/3550144992_294a8b084e.jpg?v=0

[Vealmonkey]

There should be a gasket between the carb and the intake, besides the o-ring if it has one. Also there should be a insulator between the intake and the top of the head so the heat won't transfer up through the intake to the carb and cook the fuel too early. You may have to buy a gastket kit, or if you are in a hurry go down to your local car parts place and buy some gasket material and make your own gasket or gaskets. Some people use old bicycle innertubes and make the gaskets out of rubber, but you have to be careful not to overtighten rubber gaskets since they will squeeze out and interfere with incoming fuel and air flow. Hope that helps you.

[86trizinger]

there is all brand new gaskets and o-rings on the engine.. It actually appear that the carb is warped where it meets the intake.. I can put a feeler gauge through the gap.

SO far I cannot find an exhaust for the 1970 model.. MOst start at 73 so I don't think they will interchange.. But exhaust right now is spotless... Barely any surface rust.. Where it tail pipe come out it actually is a shiny still.

[86trizinger]

Tank is clean .. well at least the coating is.. Do I remove the solder on the bottom of the tank and weld it instead... It still leaks a little bit the way it is but the sealer would fix it. Also how do I apply the tank sealer without clogging the fuel lines like the previous person did.

[86trizinger]

Just took a 2 hour drive each way with my kids feeling sick.. Boy was it a fun trip.

But I picked up some parts to help save the factory parts for the future. My son is going to be riding it and its not just for show.. All the factory parts will be saved though.
Here is what I got:
All off of 1979 ATC 90.
Gas tank-- rust free that will work for now will I am having a friend restore the original tank the right way
Rear plastic fender and seat
Rear axle assembly with brakes
front forks with axle and plastic fender.
Front tire and 3 almost rust free wheels
Headlight- still need the bracket though

I am going to remove some of the factory 1970 parts and wrap them up and put them in storage.. The factory parts are in such good shape I would rather keep them put away for a while until my son can appreciate its value. So the original Tank, fiberglass fender,metal front fender and rear axle will come off in exchange for these. Little by little I will paint the factory stuff to go back on later.

1

[86trizinger]

put the new gas tank on.. Started up on 2 pulls.. Idles really good..

Went to put it in gear.. The high/low selector doesn't work on the High setting... LOW only works.. but doesn't have much power.. Carb is leaking out of the back side so that may be a problem.

Should I bother putting money into this or should I part this out... really don't have tons of money to get it running right now. Any one fairly local to Maryland that can give a hand figuring some things out..

Also do any other engines swap into the 90 frame>?

[Vealmonkey]

On the hi/lo gearbox, you may have to rock the trike back and forth while trying to move the selector to the other range.
As for the carb leaking, get a rebuild kit and clean the carb.
110 engines will also fit the frame but you need a different front engine mount. 90 mount single hole, 110 mount 2 hole.
I told you before if you needed some help let me know.
You said you wanted a project to do with your son. You have your project.
Time to start fixing. It's not that bad.

[86trizinger]

As far as the Hi an Lo gear selector.. I goes right in LO with no problem.. Hi gear I have tried everything including rocking it back and forth... The gear indicator moves but its like its in nuetral.. Is there an adjustment anywhere for this at all?

I am going to look for a 110 carb and intake.. The fuel is coming out on a port of the carb.. Plus the carb flange is warped where it meets the intake. SO I might as well get a new one... Will one of the carbs from DRATV.com work for this?

The exhaust is like new but very restrictive.. I dont see any exhausts made for this year bike... Will a later year work?

[harryredtrike]

that thing is a beaut.looks like a deal to me

[86trizinger]

Its really is good looking considering its age.. Just not sure the person before me rebuilt the engine correctly

[Vealmonkey]

A later model 90/110 pipe should fit, like the DG pipe. If worst comes to worst, you may have to change the footpegs.

[86trizinger]

Great thanks for the info.... First I need to get the carb/engine issue fixed .. then go from there

Whats the difference from the Cobra to the DG pipe?

[Vealmonkey]

The cobra is really loud and they are a pretty cheaply made pipe. DG is a little quieter and is a little bit better quality. DG is a better pipe with increased performance than the cobra. Your pipe will not pass inside the frame, but it will run outside the frame if you replace it.

[SYKO]

look on ebay for a "pitbike" carb, I put one on my trx 70 when I had it and it ran great and only cost me like $25 shipped!

[Mr.Atc]

looks good but it doesn't have the big balloon tires in the back and it looks like the front tire size is 25x12x9 like my 200m has

[86trizinger]

the tires are 22 x 11 x 8 all the way around.. Front tire is very worn out and cracked though.

I have another set of newer forks with a brand new wheel and tire on it with a front drum brake. May not be all original when I am done but it should have everything my son needs to make it as safe and fun to ride for him. Front brake is mandatory for him since we have some very steep hills.

I am going to try and have some paint mixed up for the new tanks and forks... Trying to keep it stock color atleast. Can any paint shop mix the Parrot Green color or should I just take off the fender and have the color match that?>

[phreakboy]

That trike is definetly a keeper, the sub tranny for the hi low is actually a pretty easy thing to diagnose if you pop the cover off you will see how the lever you move moves the arm in and out to engage or disengage the gears. When you switch it to high range, does the bike still drive and act like its in low or does it just kinda ratchet or what??

http://www.bikebandit.com/houseofmotorcycles/honda-motorcycle-ct90k1-1969/o/m9159

There is a good schematic of the sub tranny there to take a look at.

[86trizinger]

In the LO position.. 1st gear is pretty low but the rest of the gears are pretty high... When its in the HI position it REV like it is in Neutral. So maybe I actually have HI gear and not LO.... The previous owner supposedly rebuilt engine.. It does have a ton of new gaskets and sounds supper quiet.. no engine noise or smoke..

How possible is it he installed something in the Sub transmission wrong?

[phreakboy]

When the one gear on mine stripped, I remember that I was able to make it stay in hi range all the time so its definitely possible. If I were you I would pull that cover and take a look.

[86trizinger]

I got the cover off finally.. seemed just like it was binding a little... I cleaned off the gears put them back in.. Now I have both HI and LO gears.

For the Carb issue should I go with a larger carb or just rebuild the stock one? DRATV has a 22mm carb for $45. Not sure which would benefit me more in the long run.

[Vealmonkey]

You have to measure the throat of the intake manifold. If the throat isn't at least 22mm, then you may seriously want to reconsider the smaller carb. Your only alternative is to do alot of blending of the inlet of the intake manifold so there is a smooth transition of the carb to the intake.

[86trizinger]

Carb is full or KREAM... I tried cleaning it overnight.. I go the gets clean but some of the passages are clogged.. Guess I will just order a replacement carb online.

[86trizinger]

just got my new PZ 19 carb from eBay.. It was a direct fit. HAs dual inlets just like the factory carb.. Put it on and got it running within 5 minutes.

Found a couple of issues though:
1. On the HI LO switch - If I tighten the cover down all the way it binds something up and does not roll freely. I loosened the screws a half turn to relieve the pressure and it shift in both Hi and low gears now. To remedy this I figure will get some cork and make a thicker gasket unless someone else knows the trick to this. Everything is put in the correct way from what I can tell.

2. Power wise it struggles to get me up my hill in my yard.. But on level ground once you get moving it start to move pretty quick. We had a Chinese 90 ATV and it was a lot more powerful then this was.

Not sure of the carb adjustments just yet so I am not sure if that is it or not. What jets should I be running? And does anyone have a link on how to tune 4 stroke carbs. Right now the carb runs the best that I can see when it is 1/2 turn out from its seated position..

-Need to know how to adjust the clutch: I was told to loosen the lock nut , then turn the screw in until I start to feel a little tension and then back off 1/2 turn.. Can any one confirm this? I did this just until I FELT a very small amount of tension and it is much better now... It actually moves.. Think I may have to go a bit tighter though.

Any input would be great.

[phreakboy]

I remember way back I had the same problem with tightening the cover, but im having trouble remembering what the problems was but I believe that something with the fork was not lining up quite right and causing it to bind.

[86trizinger]

I tried taking it apart several times... everytime as soon as I tighten down a little .. some resistance is felt on the rear wheels.

Any suggestions about my other questions.

[ParrotGreenUS90]

Your power issue seems to be a mix. I see you are dealing with the clutch and the carb, Veal knows alot with those parts. I have a fleet of five US90's and know they can move their weight. I have run into issues with an '86 TRX200sx that has decided twice that it does not wish to start when its 1/4 mile out on a lake in the winter, the third time it decides to do this it stays. I have pulled it twice along with two ice shanties and all the equipment with an all stock balloons all around US90 and it was like one of those Aircraft Tugs, no issue. The second time I had another US90 that had a rebuild a few years back along with a pair of 4-Snows on the rear pull it. These 90's have power.

Back to your 90, how big of a hill you climbing? If you are in low 1st gear you should have no issues. I have climbed hills that are close to 30 degrees that my Pack Mule, similar to a Tote Gote, has had issues climbing. What gear ratio you have? If you have the axle swap on the rear you may have a smaller sprocket. As for the carb, I would recommend a stock carb. The adjustments are in the book and has been done for years.

Nice find, Enjoy that US90.

[phreakboy]

I do agree about the gear ratio possibly being a problem, I would definitely count the teeth and see what its set up for. My original us90 will pull me around no problem and I am about 220 and it has also pulled me and my girl around at one point.

Here is a page talking about carb repair and adjustment.

http://72.52.143.80/~trikes/Manuals/ATC%20manuals/C%5B1%5D.%20Carb%20repair%20helpfull%20hints.pdf

They also host a manual for the 90 engine, but I can not seem to get it to open so maybe if you make a post in the thread someone may be able to get you a copy of it.

Thread link located below.

http://www.3wheelerworldforums.com/showthread.php?t=56218&page=9&highlight=online+manual

I am still trying to remember the exact issue I had with the hi lo unit and it binding, if I can see a pic of the inner workings I can probably remember again, its been quite a few years since mine was apart. However I will say that the cover should be able to tighten right up against the motor without any issues, mine just has rtv for a gasket so it doesnt really have an issue with thickness.

[phreakboy]

I did finally get the manual for the 90 to download so if you have trouble getting it, let me know and I will host it somewhere for you to download.

Just quickly looking through the manual, are you sure that the lever is in the proper position and engaging the for properly before you put the cover on?

Try to get the manual and on page 45 it starts showing the reassembling of the sub-tranny, take a look and make sure everything is by the book.

[86trizinger]

i'll check the gearing tonight.. as far as I know everything is stock on it though. MOtor was supposedly rebuilt.

I checked the diagrams and the HI LO gears all in correct. Only thing I did notice is the pin that going into the cover is missing but the inner pin is still intact... Not sure if that is a issue or not.