Carb Jets

[YetiWoodz]

I bought a 5mm jet kit for my 2 stroke 60/89cc engine. I made this thing that has 2 tubes that come out facing the front of the bike with a funnel on each end. And then surrounding the air cleaner, I have a box with a solid backing, angled louvred sides, and a mesh top and bottom. This significantly increases airflow to the carb. So should I use the 5.75 jet or which one? Thanks

 

[Chainlube]

Before looking into jets, you should look into porting. The carb's venturi will only pass so much air, so more fuel isn't going to help a whole lot. Maybe a little better lubrication.

 

[Street Ryderz]

I bought a 5mm jet kit for my 2 stroke 60/89cc engine. I made this thing that has 2 tubes that come out facing the front of the bike with a funnel on each end. And then surrounding the air cleaner, I have a box with a solid backing, angled louvred sides, and a mesh top and bottom. This significantly increases airflow to the carb. So should I use the 5.75 jet or which one? Thanks

A 5mm #75 jet will drown your engine.Sorry to say but the air flow theory (ducting/ram air) doesn't do anything,these are 2 stroke relying on very short pulses of atmospheric pressure reacting on the vacuum pluse,there is no constant and you cant exceed the atmospheric pressure. Jetting however is generally necessary with these engines and every one's setup being different to get it to run right.

 

[YetiWoodz]

Does anyone know what the stock jet size is on a flying horse 2 stroke 60/80cc? Will a #65 be an improvement?

 

[GreasyChris]

Stock jet is usually 70. Higher number means richer, lower number means leaner. Every bike is different based on modifications and and atmospheric pressure and altitude. You won't know until you ride your bike. If it 4 strokes under acceleration it's to rich and you need to go leaner. Don't go to lean cause you'll cook the engine. A rich running engine runs cool, a lean running engine runs hotter, go to lean and the insides melt. Its better to run on the rich side.

 

[YetiWoodz]

Ok, I called bike berry, the company I got my engine from and they said the primary jet is .78. So should I even get a richer one then that, because that's pretty rich.

 

[MotorBicycleRacing]

Ok, I called bike berry, the company I got my engine from and they said the primary jet is .78. So should I even get a richer one then that, because that's pretty rich.

Bike Berry's other biz in the same building is pot growing stuff which explains why they got that wrong.
Stock jet is a .70 and no way is it a .78
But go ahead wasting your time asking them easy questions that they are clueless about.

 

[YetiWoodz]

Idk, he did look it up the part

 

[Wrench]

Idk, he did look it up the part

Why don't you just open up your carb and see what jet ya got in there?

 

[YetiWoodz]

I might