Would a 24mm carburetor be too big?

[ismellnownlatters]

Sorry my bad

 

[Impossworld]

I am more curious about the hole that was drilled in the bottom and where exactly it was drilled...

If you drilled the jet out just get a new jet.

i think it is to the pilot circuit but I’m not too sure… I linked a picture to the one I drilled out, it is circled yellow.

 

[ImpulseRocket89]

i think it is to the pilot circuit but I’m not too sure… I linked a picture to the one I drilled out, it is circled yellow.

View attachment 184172

Ahh yes the Smolik performance method of bandaiding a too-big carb to try and pull more fuel through the idle circuit from the bowl.

They do this because the engines don't often pull enough vacuum to draw sufficient fuel from the bowl. The downside is that if you manage to pull enough vacuum it will draw a ton of fuel and never run right.

I won't speak my mind here beyond saying that if you have to mod a carb like this to make it work on an engine... it's the wrong way to go about it.

 

[DAMIEN1307]

Ahh yes the Smolik performance method of bandaiding a too-big carb to try and pull more fuel through the idle circuit from the bowl.

Probably get at least as good, probably even better results using a windowed piston, reed valve, and regular 14mm carby rather than screwing around with an oversized carby trying to make it work.

 

[ImpulseRocket89]

Probably get at least as good, probably even better results using a windowed piston, reed valve, and regular 14mm carby rather than screwing around with an oversized carby trying to make it work.

The biggest I would personally ever go on one of these engines would be an 18-19mm carb. Those are even pushing it a bit but are at least reasonable for a high performance 2 stroke of these sizes. For a race engine that is supposed to live wide open at high RPM all the time the larger stuff will work just fine. The issue is that most of us don't tend to ride wide open all the time nor do we have engines ported for racing.

People are so obsessed with the quest for maximum power that they lose sight of rideability and power under the curve at lower RPM. I will gladly sacrifice a little peak power to have an engine that will idle steady and ride nicely through the full throttle sweep.

 

[Impossworld]

Ahh yes the Smolik performance method of bandaiding a too-big carb to try and pull more fuel through the idle circuit from the bowl.

They do this because the engines don't often pull enough vacuum to draw sufficient fuel from the bowl. The downside is that if you manage to pull enough vacuum it will draw a ton of fuel and never run right.

I won't speak my mind here beyond saying that if you have to mod a carb like this to make it work on an engine... it's the wrong way to go about it.

What would be “the way” to go about it?

 

[DieselTech]

What would be “the way” to go about it?

I'd say you could tap it for a grub screw or you could possibly press a brass pin in it.

 

[Impossworld]

Probably get at least as good, probably even better results using a windowed piston, reed valve, and regular 14mm carby rather than screwing around with an oversized carby trying to make it work.

Do you know where I can find an attachment to covert my current Reed valve intake over to a 14mm to see how she would run?

 

[Impossworld]

I'd say you could tap it for a grub screw or you could possibly press a brass pin in it.

Like I know what the hell that means or how to do it sorry man I’m just getting figuring out how to tune these things good

 

[DAMIEN1307]

Do you know where I can find an attachment to covert my current Reed valve intake over to a 14mm to see how she would run?

If that intake is a 40mm from the middle of the stud to the other stud, the easiest way to do this would be to just get this reed valve below that will need NO adapters in order to fit the stock type, regular 14mm carby's.

ZTMoto Phantom 85 Bicycle Engine Reed Valve

Looking to replace the reed vavle on your Phantom 85 bicycle engine kit? Now available, the direct replacement valve for your ZTMoto, get yours now!

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