Wednesday, November 30, 2011

1978 Z50

Was starting work on the 1978 Z50. Carb wasn't stock and engine looked a bit strange. Looks like I have a 1982 Honda Passport C70 engine on this thing...not sure about the carb yet.

Follow-up ... looks like it is the matching C70 carb as well.

1964-66 Honda CT90 (200)





1964-66 Honda CT90 (200)





1979 Honda CT70 (Frame Only)



1977 Honda CT70 (7/76)






1969-70 Honda CT70 (10/69)






1969-71 Honda CT70




1978 Honda Z50 (8/77)








1970/71 Honda Z50A K2 Mini Trail 50 (10/70)






My Bikes

I mentioned I would post my bikes eventually. I currently have:


  1. Honda Z50A K2 Mini Trail 50 - Frame #310575 - 10/70 Build Date (White)
  2. Honda Z50 - 1978 - Build Date 8/77 - Frame #? (Maroon) - Engine is DA01E-2210870 (from an '82 C70??)
  3. Honda CT70 1969-71 - Frame# 114723 (Gold)
  4. Honda CT70 - 1969-71 - Frame #126060 - 10/69 Build date (Blue)
  5. Honda CT70 1977 - Frame #2602335 - 7/76 Build Date (Orange)
  6. Honda CT70 - 1979 - Frame #5003240 - Yellow (No engine)
  7. Honda CT90 (200) - 1964-66 - Frame #129600 (Yellow)
  8. Honda CT90 (200) - 1964-66 - Frame #144862 (Yellow)

Wednesday, November 23, 2011

Carbs...

So I'm messing around with the carbs on my various bikes.

It took me awhile to figure out, but it looks like someone stuck a 1977/1978 CT 90 carb on my 1970 CT 70.

This carb has a number of issues. The fuel filter cover seems to almost entirely be made out of Bondo. The filter itself is shot. I can't entirely tell if the wrong screws are holding the filter on or not, but they don't seem to "catch". I can't tell if something is stripped or they are the wrong screws. Annoyingly I dropped a tiny screw as well as the float valve while working on it last night and they both disappeared. Additionally when I pulled the main jet out of the carb, I didn't get a long jet out as I expected, just a tiny jet. Down below was a tube that looked like it might have been the stripped off jet that had somehow got stuck.

Further research seems to indicate this is maybe the correct small main jet, and there is a long pinholed jet down there that is stuck in there. Per DrATV.com at http://ep.yimg.com/ca/I/dratv_2185_59519189:


I think that is what I see down the shaft. This would make some sense as the bike actually (somehow and not all that well) ran with this carb attached before I bought it. The main jet I pulled out is #18 on the diagram and #3 is the stuck piece.

This carb also has the altitude adjustment pieces (#9) which is not on the CT70. It doesn't seem to want to seat quite right. The float valve is part of the #1 at the bottom left.  The screws 12 and 13 are slightly different and are the ones I am having trouble with (you have to refer to the entire diagram at cmsnl.com: http://images.cmsnl.com/img/partslists/carburetor-k6-77-ct90-trail-90-1978-usa_bighu0006e2614_42cc.gif


A number of things seemed to be labelled "1" on the diagram, so referring to them that way is not very helpful. Teh screen and cap that screws 13 hold in are shot.

6 Videos from CT Tech day

1982 CT70 Motor Teardown

1969 Honda Z50 K1 Restoration



1972 CT70 K1 Rebuild




CT70 K1 Rebuild Video

A good video showing before and after of a CT70 Rebuild. Useful for figuring out where stuff goes once you take your bike apart!

Tuesday, November 22, 2011

Vidoes from the Small Engine Doctor

YouTube Videos from donyboy73 "The Small Engine Doctor"

How to Check Valves for Proper Seating



How to Replace Points and Condensor on Honda Z50/CT70 (1/3)



How to Replace Points and Condensor on Honda Z50/CT70 (2/3)



How to Replace Points and Condensor on Honda Z50/CT70 (3/3)



How to Clean the Carbs on Honda CT 70 (1/3)



How to Clean the Carbs on Honda CT 70 (2/3)



How to Clean the Carbs on Honda CT 70 (3/3)




More Good Videos

Videos from TheAlexMan on YouTube

How to Adjust Honda 50/70 cc Valves



How to Check Valve Timing On Honda 50/70 cc Motors



How to Split the Cases in a Honda 50 or 70



How the Honda 3 Speed works



How to Adjust Honda Clutch



Top End Rebuild Time Lapse




Good Videos

YouTube Videos from Braaaplive2strokes.

How To Do A Top End On A Honda Trail CT90



How To Change A Piston Or Rings On A Honda Trail CT90



How To Reassemble A Top End And Gap The Valves On A Honda CT90



How To Take Off A Piston On A Honda CT90 Engine





How To Fix A Honda Trail CT90 Carburetor. 

(I actually don't necessarily approve of this one as I think you need to blow the dirt out with a carb cleaning agent after scraping it. However, it's useful anyway)





Friday, November 18, 2011

1968/1969 Honda Z50A K0

I was trying to figure out the wiring harness to one of my Z50's. I couldn't find the headlight brackets and thought maybe someone had used some different forks than the original. After searching around it looks like this bike is the first year production model and didn't have any lights or a battery.

Ok, I did some more research and it looks like I'm wrong...just checked my frame # and it is Z50A-310575, which makes it a Z50A K2.


1970-1971Z50AK2Z50A-270236Z50A-387884117,648


And the engine# is : Z50AE-293056, which is also consistent with the 70/71 model K2.


1970-1971Z50AK2Z50AE-270236Z50AE-9999996 Volt Points Engine


Per Hondaminitrail.com:


Production ModelYearSerial NumberUnique Features
Z50AK01968-69Z50A-100001~No Lights
Z50AK11969-70Z50A-120088~Battery
Z50AK21970-71Z50A-270236~Oval Badges, Foot Brake, Ugly long rear fender
Z50AK31972Z50A-1000001~1st Year of Rear Shocks
Z50AK41973Z50A-3000001~
Z50AK51974Z50A-5000001~
Z50AK61975Z50A-6000001~
Z50A'761976Z50A-6100001~
Z50A'771977Z50A-6200003~
Z50A'781978Z50A-6300003~Red Painted Fenders

Wednesday, November 9, 2011

Howdy

Hi all.

I used to have a bike shop in San Francisco many many years ago.

Now I'm back at it with a new project -- fixing up old Honda trail and mini trail bikes, in particular the CT/ST/Z series.

I picked these because they're small, there are a bunch out there, parts and bikes are reasonably inexpensive, and they are relatively simple to work on.

Also, I really like them. I'm a big fan of the whole 1960's Honda vintage bikes, especially the Dream/Benley series and styling.

So we'll see how it goes!

Only problem now is I need a bigger garage.

Currently I have 7 very rough bikes, which I will introduce shortly.

Thanks for looking.

Tom