I got an 2003 Eton 50 with a big bore kit very cheap.. now I know why
When i first got the bike it started right up but idled very high.. carb mixture screw was all the way in and the idle screw was all the way out. Bike didnt run after 10 minutes of ride time.

Checked compression... compression was down to 70 psi. SO I started to take everything apart.

Alright got the carb off. As well as the head, cylinder, and piston.

Here's what I found.

**Piston is a .96 overbore- nick in piston.. matching cyinder.
**Head is polished high compression- small nick/nipple sticking out of combustion chamber.
**Cylinder- scored but someone tried to hone it to get it run.. it did for about 10 minutes i guess.

** Carb 21mm OKO carb
pilot jet - K24
main jet - 92rd
needle position - 1 clip from bottom
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**

I need help here.. I need a new piston, head and cylinder.. I dont care if its a 50 or 70 kit but I need whatever will work with the OKO carb I currently have to save somemoney for now. Want to go cheap for now.. My son is just learning how to ride and is only 4... The bike already has a heavy spring and roller in the bike.

Also Need to know to change the jets to get this running right?

I NEED THE CHEAPEST PLASE FOR A RELIABLE CYLINDER. I found them for 150 for a stock 50 or 70 kit with no head..(i have the stock 50 head still) or 200 with aluminum head and cylinder. I was told I can get the stock ones cheaper.. But havent seen it yet.

Once I get the bike up and going again I can start with the powdercoating and modifying the ATV for my 4 1/2 yr old to start racing next year... he is very small (only 32 lbs) But he can steer it fine just like his brother's trx90.

Here's the plans there:
-I measured and I can narrow the handle bars 4 inches.
-Raising the nerf bars up 2 inches.
-seat cover is going to be taken off and the foam narrowed and lowered by 1.5"'s and then recovered with a gripper seat.
-Still working on figuring out smaller controls.. I am going to try some of the Eton MINI 50 controls for that .

I am on a budget but want it to last a little while atleast. The entire ATV has to be done for Christmas , he doesnt know we have it for him yet.

With his light weight this bike is gonna fly when we are all done.. Bike is already lightened with everything extra taken off including the electric starter,lights and battery

 

try anythingatv.com they seem to have pretty good prices on their eton parts.

 

I paid $165 for a new top end kit for my boys eton 90cc. Just a suggestion here, I would consider new shocks for your quad due to the light weight kid driving it. My son is only 65 lbs and got bounced off the quad several times, untill we changed the shocks.

 

What shock did you go with? I just weighed my son the other day.. he weighs 33 lbs.

I ordered an aluminum 70cc kit with polished and high compression head.. I got a kasea 50 for free that I plan on using that engine if I need something slower.

 

Seeins racing is planned, you need to find out the rules first.
In most santioned events that I know of, a 5 yr old cannot race a 70cc.
I recommend going to atvriders.com and going in the mini section. It's much more race oriented compared to this site.
It will help you save money from buying incorrect/not needed stuff.

 

I know he cant race a 70 already.. that is why I have the KAsea 50 engine for him to race next year.. That engine is totally be gone through over winter to be legal in the 50cc class.