Planet Minis

bidabing007

I have read that the 1969 CT70 was a prototype, Honda not being sure if they would mass build them.
So, how can you tell the difference between a 1969,70 & 71 engine?
Also, carb for same question?

I have a bike that says 9/69 manufacture date, and 1 that says 12/70, mixed them up with 3 spare motors I had sitting around. Got mixed up in move few years back. Wanting to start putting the 69 together, and want the right stuff on it. Anything else that differentiates these years is helpful.

Z

http://www.planetminis.com/f14/z50-t...ces-94207.html

bidabing007

Z,
Thanks, but looking careful at that site's info, they do not distinguish VIN's. The specs say each year starts @ 100001-200000, for the years 69,70,71.

RySem

As far as figuring out which engine belongs in that frame would be the closeness of the serial numbers between the frame and the engine. For the engine components themselves I believe they should be the same as all K0's. This is my understanding but if I'm wrong someone please speak up. My Honda ID guide shows 1969-1971 being the same with official release date of 8/26/69.

Z

Correct.

bidabing007

ok examples,
i have 3 carbs, CT70's, nipples for main fuel & reserve in totally different places, chokes operate different direction as well.
i just recently read where the 1969 is the "creme de la creme" of the CT70 series. they were also stating that the manufacutre date was not a cutoff at "12/69" if i remember right, seems they were saying august/september would be cutoff for genuine 1969 model. anyone have more to add to this manufacture story?
with them starting the 1969 vin's @ 100001- and then starting the 1970-71 series at 100001- confuses me, but now i do see where the 1969 has no "h" on the frame verses the 70-71 does have "h". on the engine of the 1969 it has an "E" and on the 70-71 engine has "HE". So i can seperate the frames & engines.

Carb & peg dilema is what i have.

Welcome to CT70 Identification Guide

RySem

The "H" is not a component of the year, but it means that it is a 4spd engine with manual clutch. All 3spd semiautomatic engines would be CT70E-XXXXXX and the frame would be CT70-XXXXXXX. If the bike is an H model the frame would be CT70H-XXXXXXXX and the engine CT70HE-XXXXXX. The H models were only available from 70-72 and are considered the rarest of the CT70s due to their lower production numbers. I'm sure many will argue that the 72 HK1 bike is the "creme de la creme" due to its rarity. Lots of one-year-only stuff on that bike. In those years you could have either an H-model, or a regular CT70 such as your 1969 bike. I'm sure others here can help you identify the proper carb for a K0. The bottom line is, everything on your bike should be the same as 70 and 71 3spd models. With a 9/69 mfg date, I would assume it to be a 1970 model year. Again, unless I'm grossly mistaken, there should be no differences from a bike made in 9/69 thru the 1971 model year.

bidabing007

NOTE:
The darker picture is from carb presently on CT 70. Notice the fuel lines next to the "fuel on" lever/petcock, hard to see but they go "hard right around the corner of the carb. The other 2 carbs fuel lines go straight out.
They also have DUAL chokes? The black knob pulls out and the swing arm choke.
Also, the swing arm chokes are different, note the position.
Also, the 2 lighter pictures of same carbs, the mounting to intake is different, they have studs coming out of them instead of bolting up to the intake. I just don't have the studs in on the far right one but the middle one comes with studs in it. The 3rd one is threaded.
Also, looking closely, the gasket is different to the intake, the very ends are open, almost like a football shape gasket with the ends cut off.

Anyone know what years these come from?

Attached Thumbnails

     

Z

The 2nd and 3rd pics aren't CT70 carbs. Those are CT90 carbs and the pull out knob is an Altitude adjustment knob.

CT90 carbs have a bigger venturi and work great on 85-88cc kits if you tune them correctly.

bidabing007

Z,
Thanks! just went to ebay, look at some more pics, seems the CT 90 also used the "wrap around" fuel line version also that i have presently on 1 of my CT's.
The question then begs:

Since I have NEVER owned a CT90 and these bikes were barn fresh purchases:

1) Why would someone put a CT90 carb on a CT70? (altitude scenario?)
2) Is it possible that Honda sold bikes in diffeent parts of the country with this type of setup, due to climates/elevations?
I know they setup cars different from state to state when it comes to emsissions, wondering if they "spot" sold bikes with this attribute?
I am having hard time thinking the folks I bought these from would go to the hassle of changing carbs, these purchases were made from folks, defintely not into the MOD craze, lol.

Z

With any 30 year old bike, they all have special suprises from previous owners who put on any part that would fit and make the bike run. Welded on kickstarters are my favorite. CT70's never came with altitude adjustment knobs and the bigger carbs. Compare the venturi's and you'll see what I'm talking about. Call the previous owner and ask.

dirtbkr188

Hey, I've got one of those...



...you did say Attitude adjustment knob, right ?

cdoublejj

what would that alt knob be for, riding in the mountains?

Z

You are one strange cat...

gary s

In the days before atv's,hunters and fishermen used ct90's to get where they wanted to go. The higher the altitude the less dense the air. If we took our bikes there we would have to change the jets and back again when we came back.

bidabing007

Very interesting, thanks guys. I am going to examine the jets, will post findings. The hunter scenario sounds great. I grew up in the city, but imagining hunting/fishing with these bikes just sounds like a blast!
I can assume then with the proper jetting, these carbs will work on my CT's?