1981 Honda Z50R

[Texan]

I want to document and share my latest project with y’all. Got this little classic about a month ago. Bought as “non-running, needs carb cleaned” The seller said he recently got it from an old man who said it had been sitting in the barn for many years after his grandson stopped using it.

The seller also said he just installed new points and condenser. I think he was trying to get it running but couldn’t. He also mentioned everything was original except the carb. I think he installed that also. I should have asked if he had the original. Tires were aired up and looked good, and engine was free and felt like it had good compression. He was asking for $300, I offered $240, he accepted right away.

I currently have it running. I will post pics and details of what it took.

Here is how it looked when I picked it up.











Couple of ads from the 1981 model

 

[Texan]

First thing I did was give it a good washing. I hate working on dirty things. It cleaned up nice. The engine obviously has been painted black, but there was red poking thru also. At this point I’m not going to try to make it look original, so I just used a black paint pen to touch up some of the scratches and scuffs. I removed the fenders and cleaned them real good. They had some black overspray on them, it came off though. Scrubbed the tires down. Wiped down the frame and cleaned the seat up. Frame paint is in good shape.


The number plates were missing, but the brackets are there. They are obsolete and aftermarket ones are pricey and only a few places have them. Cheapest I found are $20 each plus shipping. Too much for me for now, especially since it’s just a basic flat plastic oval.


I found the dimensions online and decided to make my own. I have a stack of these old exit signs I got at an auction lot for probably pennies. The backside is solid red and the color looked close enough. They are about 1/16” thick and pretty tough.


I found a website where you can input dimensions for different shapes and it will allow you to print out that shape for free. Printed out a couple and laminated them, taped them to the signs and cut them out with some utility scissors, then smoothed the edges with a Dremel. Cheap easy fix to make the bike look more complete.

 

[Texan]

The gas tank is in decent shape inside. The seller had also recently put a fuel filter inline. It had no gas, so I added some and tried to start it to just to be sure it didn’t start. It didn’t.


So the guy had said it just needs a carb cleaning, heard that one before. I took off the carb, and opened it up, pretty clean….huh? I went ahead and tore it down and cleaned it more. Put it back together, didn’t start.


Now I needed to find the specs on this thing. Luckily I found the 50 page User Manual and 100 page Shop Manual online in pdf format for free. I downloaded and printed both. They are a BIG help! Now with the specs, I started troubleshooting. Pulled the plug and it’s gap was under the spec of .024-.028”, so I set it to .026”. It didn’t start. I had previously checked to see if had spark, it did.


OK, so the guy said he replaced the points and condenser. I watched a few videos about those, it’s also in the books. They are under the flywheel, but you can set the point gap without removing the flywheel. They appeared new, so I guess the guy did replace them, but the point gap was too big, I set it to the spec of .012-.016”.


Next I learned how to set the valve clearances. Spec is .002”. The exhaust was good, the intake was pretty close but a little too big, so closed it up a bit. Tried to start it....no go.


This is the way the carb was setup, no air cleaner and all.

 

[Whitetrashrocker]

Nice find.

What's the plan? Keeper or flip?

 

[Texan]

I recently read on the forum about fuel filters and the how some are for gravity fed and some are for pumps. Then I read in the bike manual that the gas tank actually has a filter inside it. I was thinking the added fuel filter was causing some problems, so removed it. Tried to start it and nope.


Pulled the plug and it was wet. I figured it was from repeatedly trying to start it. Aired it out, and tried again. Boom, it started! But only wanted to run on choke. I tried messing with the air and idle adjustments, but could not get to stay on without choke and without blipping the throttle.


Next day or so when I tried to start it, it wouldn’t and the plug would be wet. So now I knew it was the carb was flooding. I took the carb apart again and noticed the float needle tip was just metal no rubber tip.


I knew the guy said the carb was not original, but figured it was at least the same type /size. The carb on here is a Keihin PB type. The spec is Keihin PA type. This PB is bigger than the PA. I could not find much info on the PB type, seems like they are not too popular.


I started looking at replacement PA carbs specifically for the Z50R, which were plenty and cheap. Found a knockoff on ebay for $15 which was less than an carb repair kit…..not so easy. The PB carb being bigger had a bigger intake manifold bolt spacing (42mm). I would not be able to using the existing intake manifold with the new “oem style” carb (32mm).


Then I remembered I had seen some small carbs and intakes in my Honda treasure stash. http://www.diygokarts.com/vb/showpost.php?p=492218&postcount=75


I actually found a PA carb and intake Of course the carb is trash, but the intake was exactly what I needed. Cleaned it up real good. Perfect fit. New carb is quite smaller than the old one, but that's the spec.

 

[Texan]

Now it starts up every time!! Taken it for a few spins and it works fine. I was afraid the clutch would need work, but it shifts smoothly. I’ve gotten a top speed of 21MPH. It surprised me. This little 49cc engine pulled my 200lb butt uphill fine. It’s a fun little bike for sure.


Other things I did to it:

-Tuned the carb

-Changed the oil

-Removed, cleaned and lubed the chain, also cleaned up the sprockets.

-Replaced the broken brake lever (had one in my Honda treasure stash)

-Patched up the seat, sealed the one hole on the top with plastic epoxy and used Gorilla Tape for the tattered edge.

-Put decals on the number plates. Only spent about $5 for the numbers and letters.

-Checked every nut and bolt for tightness

-Adjusted the brakes


Things to do:

-Need a better throttle cable with a slanted carb cap

-Gas Tank decals (already ordered)

-Restore or repaint chain guards (should be red)

-Touch up paint on the pegs and rear shocks

 

[ezcome-ezgo]

This is good. Keep 'em coming.

 

[Texan]

Nice find.

What's the plan? Keeper or flip?

It's a keeper for sure! Daisy Duke likes it

 

[Texan]

This is good. Keep 'em coming.

Thanks EZ, but I'm spent for Today LOL. Haven't typed this much in awhile. I will for sure post more updates as I spruce it up.

 

[Randy H]

Very, very nice.

 

[bob58o]

Thanks EZ, but I'm spent for Today LOL. Haven't typed this much in awhile. I will for sure post more updates as I spruce it up.

You type too much! LOL
JK, nice work!!!