Carb Differences and will it work?

[cruelsoul]

I have been sitting here thinking about carbs and it has me thinking can I use a carb from a 4 stroke on my 2 stroke just a basic 4 stroke carb you knoew nothing crazy or anything like that cause I have a carb here from my old 450r and I was wondering if I just changed out the jetting etc. if it could work with no problems?

 

[cruelsoul]

Ok the carb is 42mm so its way to big but what if I found a nice 30mm-33mm carb then possibly a do'er?

 

[bonzaiking]

looks to me you are wasting your time if you want a good carb take a keihin pwk they make great carbs no 4 poke carb will work

 

[sicivicdude]

Carburetors designed for 4 stroke engines are designed around a basic principle. At lower RPM's, the fluctuations in velocity are great. Think about it, a 4 stroke only intakes air half as often as a 2 stroke. When the intake valve opens and air begins to rush into the cylinder, the pressure inside the carb drops VERY fast but the flow is still moving relatively slow. Because carburetors are designed to work off vacuum induced by flow (see Bernoulli's principle), they're designed NOT to function with engine vacuum. In fact, they're designed to work with engine vacuum to regulate flow speed at lower throttle settings to nullify the effects of engine vacuum on the fuel pickup rate. That's why most have a butterfly and then a vacuum controlled slide. If you watch the slide as the engine comes off idle, it bounces up and down.

2 strokes have a shorter intake tract and need fuel and air twice as often. They need a simpler and more direct fuel supply.

 

[cruelsoul]

looks to me you are wasting your time if you want a good carb take a keihin pwk they make great carbs no 4 poke carb will work

technically I am not wasting my time cause thats why I am asking before i try it out

 

[cruelsoul]

Carburetors designed for 4 stroke engines are designed around a basic principle. At lower RPM's, the fluctuations in velocity are great. Think about it, a 4 stroke only intakes air half as often as a 2 stroke. When the intake valve opens and air begins to rush into the cylinder, the pressure inside the carb drops VERY fast but the flow is still moving relatively slow. Because carburetors are designed to work off vacuum induced by flow (see Bernoulli's principle), they're designed NOT to function with engine vacuum. In fact, they're designed to work with engine vacuum to regulate flow speed at lower throttle settings to nullify the effects of engine vacuum on the fuel pickup rate. That's why most have a butterfly and then a vacuum controlled slide. If you watch the slide as the engine comes off idle, it bounces up and down.

2 strokes have a shorter intake tract and need fuel and air twice as often. They need a simpler and more direct fuel supply.

Thanks alot for the info man figured I would find out what is what before trying anything out I read an article online saying that you can make it work just have to change a few things on the carb.

 

[Blaaster]

(see Bernoulli's principle), yeah

http://en.wikipedia.org/wiki/Bernoulli's_principle

 

[slickerthanyou]

Carburetors designed for 4 stroke engines are designed around a basic principle. At lower RPM's, the fluctuations in velocity are great. Think about it, a 4 stroke only intakes air half as often as a 2 stroke. When the intake valve opens and air begins to rush into the cylinder, the pressure inside the carb drops VERY fast but the flow is still moving relatively slow. Because carburetors are designed to work off vacuum induced by flow (see Bernoulli's principle), they're designed NOT to function with engine vacuum. In fact, they're designed to work with engine vacuum to regulate flow speed at lower throttle settings to nullify the effects of engine vacuum on the fuel pickup rate. That's why most have a butterfly and then a vacuum controlled slide. If you watch the slide as the engine comes off idle, it bounces up and down.

2 strokes have a shorter intake tract and need fuel and air twice as often. They need a simpler and more direct fuel supply.

That about sums it up!