Kymco agility 50 Big bore kit

hasi897

New Member
Hello, I heard a compression loss (pop sound) from the Gy6 Engine and a few days later heard the pop again and the motor died. So far what I have gathered is because of the wrong fuel type (E10 Euro95). Also the last time I changed the engine oil it didn't go very smooth, I flushed it a little, and then the oil filled in too slowly and had a little bit of excess 1cm on the dipstick. Can the excess engine oil also be a problem?

Anyway, i think the engine took some damage and I would like to build it myself. I have done some research and would appreciate any tips or videos or guides. I would also like some information on the parts to order if anyone has experience. Also if someone has done this please get in touch.

Kymco agility 50 2007 4T
 
Advertisement - register to remove this

I'd recommend ordering a 47mm/72cc cylinder kit, they work with the original head and can be obtained quite cheaply.



I have always had good luck with this specific kit.
I've rebuilt Kymco GY6 engines at least a dozen times already, the performance gain is pretty dramatic. The scooter will gain a significant amount of torque and will accelerate much better.


Before doing this, I'd look into other parts of the scooter first. I don't believe your issue is immediately engine related but more likely in the carburetor. These engines are hard to kill, I'd go over other things first before tearing the engine apart.

A compression test is the only way to confirm whether the engine has enough compression, I'd see if you can get your hands on one of those.
It's gonna be a really useful tool if you plan on working on engines in the future.
 
Thanks for your response you are indeed right I think. I still haven't found my problem. I couldn't manage to take the cylinder off and the cylinder was smooth so I was advised by a mechanic to put it back together. Now the engine runs but not sure what the problem is. I got the valve clearance set from a shop but they set it to zero, I couldnt even stick in a 0.04mm gauge in. I changed to 0.1mm However, the proper is still there. There is no power from the engine and this what it sounds like.
 
have you cleaned the carburator? including the main jet and the pilot jet?

also, does the valve from the carburator goes up and down smoothly*
other thing to check are:
- fuel filter
- air filter
- vacuum diaphragm (remove the top 2 screws from the carb)


*how to check: remove the air inlet and get a small screwdriver (flathead) underneath the cylinder ( carb vacuum piston)
 
Last edited:
Yes the carb is clean but I watched the video in slow mo you can see gases leak. I guess the nuts that go over the rocker assembly are not tight enough.
 
Can you verify the vacuum diaphragm works?

Take the carb off and move the throttle slide up with a flathead screwdriver. When you remove the screwdriver, it should slowly fall back into it's closed position like this:


If it immediately slams shut, the diaphragm is shot.


I have to admit though, the engine sounds a little rickety though that could just be the valve cover rattling if you say the nuts aren't tightened enough. How does the kickstart feel?

The fact that the cylinder walls looked smooth is a good sign, if the engine has for example ran out of oil before the walls are usually all scraped up.
 
I'd recommend ordering a 47mm/72cc cylinder kit, they work with the original head and can be obtained quite cheaply.



I have always had good luck with this specific kit.
I've rebuilt Kymco GY6 engines at least a dozen times already, the performance gain is pretty dramatic. The scooter will gain a significant amount of torque and will accelerate much better.


Before doing this, I'd look into other parts of the scooter first. I don't believe your issue is immediately engine related but more likely in the carburetor. These engines are hard to kill, I'd go over other things first before tearing the engine apart.

A compression test is the only way to confirm whether the engine has enough compression, I'd see if you can get your hands on one of those.
It's gonna be a really useful tool if you plan on working on engines in the future.
Post automatically merged:

I'd recommend ordering a 47mm/72cc cylinder kit, they work with the original head and can be obtained quite cheaply.



I have always had good luck with this specific kit.
I've rebuilt Kymco GY6 engines at least a dozen times already, the performance gain is pretty dramatic. The scooter will gain a significant amount of torque and will accelerate much better.


Before doing this, I'd look into other parts of the scooter first. I don't believe your issue is immediately engine related but more likely in the carburetor. These engines are hard to kill, I'd go over other things first before tearing the engine apart.

A compression test is the only way to confirm whether the engine has enough compression, I'd see if you can get your hands on one of those.
It's gonna be a really useful tool if you plan on working on engines in the future.

I'd recommend ordering a 47mm/72cc cylinder kit, they work with the original head and can be obtained quite cheaply.



I have always had good luck with this specific kit.
I've rebuilt Kymco GY6 engines at least a dozen times already, the performance gain is pretty dramatic. The scooter will gain a significant amount of torque and will accelerate much better.


Before doing this, I'd look into other parts of the scooter first. I don't believe your issue is immediately engine related but more likely in the carburetor. These engines are hard to kill, I'd go over other things first before tearing the engine apart.

A compression test is the only way to confirm whether the engine has enough compression, I'd see if you can get your hands on one of those.
It's gonna be a really useful tool if you plan on working on engines in the future.
Hoi ik zit de denken om een 72cc te monteren op mijn kymco agility 50 maar moet ik daarnaast nog iets veranderen of moet ik nog rekening houden met iets en heeft ie dan nog genoeg kracht om met elektrische start aan te gaan
 
Last edited:
Je gaat de carburateur opnieuw af moeten stellen maar dit is meestal niet heel lastig.


De elektrische start begint naar mijn ervaring pas problemen te krijgen als je richting een 80cc gaat of als je de compressieverhouding sterk verhoogt. Met alleen een 72cc kitje zou je elektrische start prima moeten blijven werken.
 
So did reassemble the engine and made sure everything was tight. I don't know if it was due to using cheap gaskets. Talked/showed the problem to a few mechanics and it still remains an unsolved mystery.
 
Je gaat de carburateur opnieuw af moeten stellen maar dit is meestal niet heel lastig.


De elektrische start begint naar mijn ervaring pas problemen te krijgen als je richting een 80cc gaat of als je de compressieverhouding sterk verhoogt. Met alleen een 72cc kitje zou je elektrische start prima moeten blijven werken.
wat voor sproeier gebruik je voor een kymco agillity
 
Back
Top