Advice for new cylinder head and top end components

GoldenMotor.com

Arazzer

New Member
May 24, 2020
2
0
1
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Hello Everyone,

Not sure why (have a couple ideas, will discuss below), but my 80cc "zeda" motorized bike started making some metal noise and bam, stopped running (on my 3rd gallon of gas, fml). I had tried a recommended bp6hix or whatever iridium plug, but that plug protruded too far into the cylinder and got smashed back up, not sure if a piece from the piston got dislodged or what, either way, engine went out and I was left with a giant hill to deal with on my own. I took the top end off and clearly there was some piece of metal causing all types of damage to the cylinder, the piston and the cylinder head.

I now need to replace the top end, and options are abound on the internet. My engine has a stated stroke of 40mm, does that mean I need a special head or what? I saw a CNC head/top end kit from ebay that is $32 (link below), will this work fine? Is there anything I need to do to make sure my crank is fine? After it broke, there was clearly a loss of compression but I could get the motor going again and it helped me out as I made my way towards home.

Working on these bikes is fun, but damn, what a f'ing PITA.

Thanks!

Kit I"m looking at:


Engine I purchased:


Pictures of my bike also attached.
 

Attachments

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
You may want to ask the original seller if all that will fit- there are a lot of variations when it comes to these.
Why do yiu think it blew up? Did it have a warranty?

I have had a lot of these, and even the crappiest ones didn't blow up, ever, much less 3 tanks in.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
Can you post pictures of the damage?

Did it run lean?

If you run the suggested 16:1 like they keep recommending for break in, and the carb is set just a little on the lean side......you get bad results.