Non working Engine/Carb from other day

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DanSpd

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So some of you may know that my engine gave up on my because head went lost. The worst part about that is me and my dad noticed after we took carburetor apart, etc..


So I decided not to be a baby and took engine and carb apart and took some pictures. I was going to write a note to each picture but then was too lazy to do it.


Maybe if you see something that may cause engine not start please post here.


Thanks


Note to moderator: Let me know if pictures are too large so I could re-upload them.
 
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OK last pictures.


Also I screwed up and pictures are in wrong order >.<
 
The piston looks kinda used up may be time for a new head kit. If you do get one make sure you clean the crank case out good looks like there was something in there that messed it up or maybe the piston ring was not in the grove right when it was put together. Hard to tell.....
 
Yea I guess the engine was used a lot and maybe its time for new head kit or maybe engine itself.


I think you are talking about those scratches on the head inside.


For unknown there are some of them on piston, head inside, and on the lower part of the engine.
 
I have CY 30.5cc engine and since it looks like I need new head kit or new engine.


What would you guys suggest?


Should I go with new head kit for CY30.5cc or buy new CY29RC engine?
 
I have had 2 headkits get "scratched" up like that. They were in good tune BUT supposedly the theory is under hard long full throttle passes the piston and head get hot and expand at different rates and rub on each other even through the ring. Any ways both times it happened to me I had held it wide open and went end to end on football size fields back and forth 20-40 times through multiple tanks lots of hard driving.


I have since switched to relieved pistons from ONB and do not hold my throttle wide open for very long and I don't make lots of wide open back and forth passes any more.


Those scratches are fairly common for 1/5 scale 2 stroke engines. You can look it up on the net and find lots of examples. Relieved pistons and a healthy tune along with kind running supposedly fix it. So far so good for me!
 
From what I see, the engine have seen better days, but you can use it a lot more.


Is that the ring is stuck on your piston? specially where the scratch is?


Is the plating in good shape in the cylinder?
 
Thanks hamster huey now I know not to run engine full throttle and tune it before riding. Let's hope I can get head kit somewhere really cheap :)

From what I see, the engine have seen better days, but you can use it a lot more.
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Yes I will hope I could ise it much more if I change head kit.

Is that the ring is stuck on your piston? specially where the scratch is?
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No, ring can move either to left or right.

Is the plating in good shape in the cylinder?
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Not sure what you are asking about.


So I guess I will be looking for CY30.5cc head kit for maybe $150 and not new engine for $400 lol


Any suggestion where I can get good head kit?


Edit:


Also could I possible get a head kit with two ring piston?
 
don't forget if you want a 30.5cc you need a + 2mm stroker crank.


Piston ring are only available as single ring for those engine, a single ring piston exist since several years in performance two stroke engine, most sled's, dirt bike etc... use single ring.
 
Martin said:
don't forget if you want a 30.5cc you need a + 2mm stroker crank.
Piston ring are only available as single ring for those engine, a single ring piston exist since several years in performance two stroke engine, most sled's, dirt bike etc... use single ring.
Click to expand...
Currently I have 30.5 engine by CY, and I thought maybe I can get new piston and head only? not the whole kit
 
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