mikuni from a 2 stroke on a 4 stroke?

[Kaptain Krunch]

I have always thought that it didn't matter if a carb was from a 2 stroke or a 4 stroke. But recently someone told me if i wanted to use the mikuni carb i have from an RM125 2 stroke on a 4 stroke bike i would have to cut out the "emulsion tube", is there any truth to that? Im pretty sure i've seen carbs from 4 strokes on 2 strokes and vice versa, but i've never tried it myself.

 

[freakboy]

try it and find out.

 

[Russ2251]

No difference.

 

[Kaptain Krunch]

Didnt think so, but i figured i should make sure before i made a 2 into 1 intake.

 

[Rotore]

No difference

 

[Russ2251]

Somehow, I think it's believed that when using a carb from a 4 cycle for use on a 2 cycle, that the jets strain out the oil molecules.
Kinda' silly when you think about it.
Yet many folks believe there is a difference.

 

[Kaptain Krunch]

The reason i was given sounded harder to believe than that. He claimed 2 stroke carbs had emulsion tubes which helped get fuel into the engine at low rpms because 2 strokes create less intake velocity than 4 strokes. I've never heard of an emulsion tube (could be real, I'm not great with carbs), but it made no sense that 2 strokes would have less intake velocity than 4 strokes, and this emulsion tube just sounded like it did the same thing an idle circuit would haha.

 

[theo]

You have to plug off the oil injection tube.

 

[jr dragster T]

The Emulsion tube is the long tube the main jet threads into. I noticed on alot of Mikuni's off 2 strokes have a shield on them sticking into the carb venturi on one side.

 

[Kaptain Krunch]

Ooh, Hmm maybe that's the part that I was told needed to be cut off...

 

[jr dragster T]

Do you know the part I am talking about? Its a cutaway of the emulsion tube, Will be brass and it blocks the needle on one side right in the carb body venturi.

 

[Kaptain Krunch]

Yea, right where the slide needle goes in right? Would that affect it working on a 4-stroke?

 

[jr dragster T]

Correct. I really don't see it affecting much.

 

[EagleTalons]

It would lower the pressure on slide needle side.