I've seen alot of complaints about lack of power with the 2-stroke minis. I own a `04 Viper 90 and from the factory Eton had this thing so choke up with the fony air filter and a lack of fuel. Take the stock air filter and box and throw it away. K&N makes universal filters that will fit just about any carb. Then pull the main jet out and use a one sixteenth drill bit to bore it out. Throw away the premix oil tank and mix it 32:1. Unbeleivable what this does.

 

Can you elaborate a little on what kind of extra power you got.Was it just right across the board or low end or top end?Always good to hear about inexpensive power![img]i/expressions/face-icon-small-happy.gif[/img]

 

1/16th seems awful big, I'm wondering if your pilot and needle are lean? You can buy micro drill bits from Harbor Frieght for about $20 delivered.

Also want to warn people that the jetting on these is VERY sensative.

 

Dude,
The stock main jet on the Viper is an 85. By using a 1/16 drill bit, you just drilled it out to 159!!! I see many, many fouled plugs in your immediate future. An extremely modified 90cc doesn't even need a jet that big. A stock 90cc with a K&N or Uni filter makes the most power with a main in the 100 neighborhood. If you add a true 2-stroke pipe you might need to bump it up to 105 to 110. No where near 159! I bet you've got the jet so big that you could remove the jet completely and the performance wouldn't change from your current set-up.

 

Hmmmmmmmm if changing the jet back it too much trouble, just drain the gas and dump some alky in it. Should be just about right? [img]i/expressions/face-icon-small-smile.gif[/img][img]i/expressions/face-icon-small-wink.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]

 

Yes I did drill the main jet out to 1/16 and I haven't had a fouled plug since. You used to not beable to ride behind it because of the rich fuel and oil ratio it had. Fuel consumption is better and power is better. I'm sorry if you can't beleive this but I tried my numbered set and I kept coming up to lean.

 

Josh's Eton 90 did great on the trails and mud last weekend. We added a 54mm piston and jug. Plus a 2 stage Uni filter. I raised the needle 1 notch and drilled the jet to about a 110. The idle is a little hard to nail down but from what I hear the stock carbs. don't idle well after you start modifying these quads.

 

I have 2 Eton 90's. They are both '05 models. This week, I put on a true 2 stroke pipe, did the rollers and springs in the tranny, added a Uni filter, and went with a 125 main jet. It now has a true power band. You can really feel it hit. I am going to Glamis tomorrow to really try it out. I left one bone stock, so I'll be able to tell you EXACTLY what this set-up is doing for me. I am running mixed at 32:1, and I was able to keep the battery with some mods. I have a 120 main if it's too fat, but I will give the plug a look after a good hard run. After the little guy rode it a bit, it seemed to idle fine.
I'll let you all know!!!!!
Jesse

 

I've got a 93cc with pipe and 20mm carb with K&N and I'm only running a 105 main??? [img]i/expressions/face-icon-small-confused.gif[/img]

 

hey jesse...im interested in how it works out!...those are some simple and fairly inexpensive mods....im making a list so when my little guy is ready[img]i/expressions/face-icon-small-wink.gif[/img]