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-   -   Just pulled all the China engine parts (see puked guts out) (http://www.gz250bike.com/forum/showthread.php?t=7900)

spldart 05-07-2017 10:53 AM

Just pulled all the China engine parts (see puked guts out)
 
Pictures will follow shortly :tup:

That rapping sound from inside the engine got so loud that you could hear it echoing
off of cars stopped in traffic with yah so a tear down was imperative. :cry:

New China gaskets, rigged, and all the old parts got cleaned up and cyl got quick hone. :)
Rigged means I stacked to cylinder base gaskets and I added two shims to the head
gasket as to maintain reasonable deck height. *see issue in 'puked her guts out' thread* :(

What I found during tear down...
1) Gasket was starting to blow out in the same place.
I'm not surprised as I had seated it 3 seperate times. That's a no no.

2) Piston pin was a tiny bit loose in connecting rod in a rocking fashion.

3) Piston pin retainer clips lost most of their tension. I was able to pull them with a
fingernail! :???:

4) More carbon buildup than expected and mostly around intake side.
Guess I'll use my stem seals on the intake valves sometime soon.

5) The head crack hasn't grown any. I'm very fortunate the cracks terminus's both end
in large radius's.
Any structural engineers out there will know what I'm talking about :P

Old pin is very snug on rod and piston. Old clips are very high tension. New gasket
went in with one shim on top and one on bottom which should help sealing.
Bike started on first try. No bad noises. :tup:
Later took it a few blocks test ride :ride: and it was still sounding great.
Later today I'll put some miles on it.

Pictures coming in minutes. :)

spldart 05-07-2017 10:55 AM

1 Attachment(s)
Chinese cylinder top. You can see at the front where the gasket was starting to blow
gasses through. :doh:

http://www.gz250bike.com/forum/attac...1&d=1494168860

spldart 05-07-2017 10:57 AM

1 Attachment(s)
For only a couple thousand miles or so I sure got a lot of carbon built up on the chinese
piston. :shrug:
Rings were starting to get to much gap movement too :hmm:

http://www.gz250bike.com/forum/attac...1&d=1494168961

spldart 05-07-2017 10:58 AM

1 Attachment(s)
http://www.gz250bike.com/forum/attac...1&d=1494169077

spldart 05-07-2017 10:59 AM

1 Attachment(s)
The infamous CRACK!!! :wtf:

http://www.gz250bike.com/forum/attac...1&d=1494169137

spldart 05-07-2017 11:01 AM

1 Attachment(s)
I found that this journal upper half and the other cam journal lower half had some slight
wear marks showing. Dunno how normal that is for this many miles.

http://www.gz250bike.com/forum/attac...1&d=1494169220

spldart 05-07-2017 05:40 PM

Put ten miles on it.
Minor oil leak. Fixed that just now.
Slightly down on power. Betcha my mileage goes back down to 68 mpg too. meh

But!
It sounds perfect. Absolutely perfect.
Like new.
Wonder how long this will last XD

Vegas Street Rider 05-07-2017 11:12 PM

Hope this is the last time for you. You are due for some success.

Water Warrior 2 05-08-2017 09:23 AM

Quote:

Originally Posted by spldart (Post 87591)
I found that this journal upper half and the other cam journal lower half had some slight
wear marks showing. Dunno how normal that is for this many miles.

http://www.gz250bike.com/forum/attac...1&d=1494169220

I wouldn't get to excited about slight wear marks. Of course if you had actual grooves that would be another can of worms. How many hours since the start of your initial rebuild? You must be far more inqusitive and amazingly patient than most of us.

Now get out there and ride. Here's a plan. Somebody in your area should gift you a Gremlin Bell. It made Lynda's GZ run like a champ, never a hiccup.

spldart 05-08-2017 09:04 PM

I'll put it aside the gremlin bell already there. :)

The marks are new since the rebuild a couple thousand miles ago.
Since the noise is gone I've dismissed them at this time as a problem.

Now I'm gonna obsess about the carb.
Cold start and running for the first 2 or three miles is a 6!7ยข#!
Used to run better long time ago.


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