Finally got a Honda z50!

[coolpool]

I was recently in Southern Ontario and was chatting with my old friend about any and all vintage machines which we both enjoy immensely. He mentioned that at one of the places he picks up firewood he seen an older Honda 50 minibike sitting in the corner of one of the barns. Knowing that I wanted one, he talked to the owner and got it for $100.00 with potential transmission issues. I only have one picture but it looks fairly complete and I'm pretty sure I can fix it up for less than $1000.00 even with shipping costs to Alberta which is what they're worth up this way. The hard part is finding the darn things....fixing is easy

[shortline10]

Nice score

[knappyfeet]

I love it!

[kiser]

Great find, they are a blast!

[coolpool]

Fast forward almost 1 year and I finally have this beast at home. Physically it's in good condition with a clean tank, intact seat, good tires and decent plastics. All controls still move as it was stored indoors since parked. Wear on the handgrips don't show excessive use either. The bad is it does roll freely but the kicker won't budge the motor. The crankcase was empty when I got it so I filled it and the cylinder completely with ATF and fresh oil and let it sit for a few weeks....no change. I ordered a factory manual and will pull the motor and tear into it and see what surprises await. Kickstand1 mentioned I should look into getting the dents in the tank fixed using the paintless dent removal method. Once it's running I'll definitely do that.

[shortline10]

Nice score , I would pull the flywheel cover and rock the crankshaft back and fourth .

[big specht]

Second that and you can use a stud welding gun to pull out the dents

[coolpool]

I took your advice and pulled the cover. I can freely spin the flywheel back and forth but then I'll hear a click inside and it stops. If I play around with it it goes again until the click then stops. Trans is all the way in neutral up as far as i can feel with the shifter. I don't think it's grabbing any gears as I push down at all. Maybe pull the head and see if the cam chain isn't broken or a valve dropped?

[shortline10]

The older model z50 has a manual timing chain tensioner setup so if it’s not maintained things happen

[coolpool]

That's what I'm leaning towards. I can feel vacuum when the piston moves slightly so i'll pull the tappet covers and see if anything is moving there. There's definitely something up with the transmission as I can't get it to go in any gear at the moment. We'll get her figured out soon enough. Thanks for all the input folks!

[coolpool]

Update: Appears that two of three bolts came out of the cam gear and the 3rd loosened off and caused some damage. The exhaust valve hit the piston and bent when it was out of time momentarily but didn't seem to hurt the piston at all. Unfortunately I'll need to replace both side covers as the cam was drifting back and forth and damaged both. What I'll do right away is:

- replace both valves, guides and seals
- replace both side covers
- mic the bore and hone as required if in spec
- bore out if above is not in spec
- replace piston/rings

Potential Fixes:
-replace with new stock piston/rings if still in spec
-oversize piston/rings if needed
-replace cam gear
-replace cam due to surface scratches (anyone think it's in too bad of shape?)

I was very surprised how bad the muffler is compared to the rest of the machine. Lots of patching and will need a nut welded on for the side shield to bolt to.

The transmission is still an issue but that will get looked at in good time.

[shortline10]

The cheap way out is to just buy a complete 70cc topend kit . Most are less than 100.00 and it’s a definite power boost .

A kit like this .
https://www.ebay.com/itm/28398662938...3ABFBMhuuspIdh

[coolpool]

That's definitely a great option shortline. Curious, will the 70cc kit bolt on directly to the 50cc block? With CDN exchange and shipping it'll be around $200 but still cheaper than OEM I'm thinking.

[shortline10]

Yes it all bolts right in , cylinder will fit in the cases .

You can also go this route and make a rocket ship lol .
I’ve done a few and they get scary fast for a short wheel base .

https://tboltusa.com/store/crf50-z50...0_122_124.html

[coolpool]

Yikes....no I'm lucky the mini bike is even allowed at my place after my sons bad motorcycle accident in 2012. Thanks for the ideas though :-)