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Makotosun

1973 Z50 mini trail

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Replied by Schu on topic 1973 Z50 mini trail

Oh my! Thank you so much for that info Ray.
It sounds like I need to do some research and learn more about this little Honda.
I did join a forum called “lilHonda” and have started reading thru applicable posts, but I have yet to ask any questions of the group.

With the weather soon warming up in Michigan my attention will go to my Yamahas and this little guy will go on the back burner. It is the winter months that I do most of my refurbishing work because there is nothing else to do!

Thanks again
Schu

CT1B, CT1C, JT1, JT2, CT2, DT360A, GT80B, DT100B, DT125B, DT175B, DT175C, DT250B, DT400B, Z50, SCR950

Someday, you'll own some Yamahas
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21 Mar 2025 15:09 #11

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Replied by Wrench66 on topic 1973 Z50 mini trail

You're very welcome.
If you have someway to measure the bore then you can tell if it's a 70cc or not... like I said, the cyl head certainly is lol.
best,
-Ray 
Nothing makes me smile like the smell of Blendzall green label ;)
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21 Mar 2025 15:54 #12

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Replied by Schu on topic 1973 Z50 mini trail

I want to get a handle on this before I set the project aside for a bit.
But next on my list is tires so I can make this thing a roller and queue it up in the barn with the others. 

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Schu

CT1B, CT1C, JT1, JT2, CT2, DT360A, GT80B, DT100B, DT125B, DT175B, DT175C, DT250B, DT400B, Z50, SCR950

Someday, you'll own some Yamahas
Last edit: 21 Mar 2025 19:13 by Schu.
21 Mar 2025 18:08 #13

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Replied by Schu on topic 1973 Z50 mini trail

Well I confirmed it has the standard 39mm cylinder bore of the Z50A and not the 47mm bore of the CT70 from which Ray said the head came from.  So I guess I now know why it had such low compression and would not run regardless of the fact that it was getting fuel and spark. Glad I didn't waste $80 on the cylinder head I bought on ebay. I'm also glad it came as the complete assembly with the valve train. Lesson learned...
Schu

CT1B, CT1C, JT1, JT2, CT2, DT360A, GT80B, DT100B, DT125B, DT175B, DT175C, DT250B, DT400B, Z50, SCR950

Someday, you'll own some Yamahas
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Last edit: 22 Mar 2025 12:00 by Schu.
22 Mar 2025 11:58 #14

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Replied by Schu on topic 1973 Z50 mini trail

Well I got my new tires mounted and have boxed up the top end components to sort out as next winters project. I may buy a complete big bore kit with an aftermarket exhaust. After all, the bike was free to me so I guess I can invest in it. Plus I am happy with how it cleaned up.

imgur.com/a/RU74oWc
Schu

CT1B, CT1C, JT1, JT2, CT2, DT360A, GT80B, DT100B, DT125B, DT175B, DT175C, DT250B, DT400B, Z50, SCR950

Someday, you'll own some Yamahas
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30 Mar 2025 17:49 #15

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