Simplified---Adding A High Speed Circuit To A WG Carb

[Mastermind]

Ok. Just the basics.

I start with a 4mm x 25mm allen head screw to make my needle from.

The paper in the picture has the dimensions on it.



A little time with the lathe, and we have needles.

 

[Mastermind]

This pilot hole is the right size to run a 4mm bottom tap in to create the threads...



....but first you need to drill into the main well to feed the main nozzle.

In order to keep the drill centered, you need a steel bushing that just barely slides into the hole.



I make the hole into the well .050", so my bushing has a hole that my .050" drill bit just fits thru.



Simple huh?

 

[Mastermind]

To feed the new high speed circuit, I drill a .080" hole here.



Notice that I cut a channel over to it. This might not be 100% necessary. I had a saw that was leaning out in long cuts once, and adding this channel helped. I'm not interested in debating any aspects of this mod. Use it or not....your call.

I counter drill a place here for the oring.

 

[Mastermind]

That's the simplest I can explain it.

Questions?

 

[Mastermind]

Oh.....part numbers.

 

[timg]

Thx. for the tech tip and part numbers boss man Senior Mentor Styling at it's finest.

 

[Lightning Performance]

Oh.....part numbers.

View attachment 278796

Franks

 

[Absolution]

I may never do it. But this was actually a lot easier to follow.

 

[jmester]

Makes sense to me. Clear pics and detailed description. Makes a great thread in my book.

 

[Logsdendave]

Shucks! That’s it.

 

[huskihl]

Easy peasy

 

[Saber_DD]

Thank you for sharing.

 

[Mastermind]

@Pintail120

 

[ammoaddict]

Is that a 3120xp carb?

Sent from my moto g(7) power using Tapatalk

 

[Mastermind]

Is that a 3120xp carb?

Sent from my moto g(7) power using Tapatalk

Yeppers

 

[Canadian farm boy]

Yeppers

Perfect how to thread. Short and to the point. Nice job Spanky.

 

[Pintail120]

@Pintail120

thank you kindly for writing this up, very grateful !
I have only one question:

This pilot hole is the right size to run a 4mm bottom tap in to create the threads...

I assume the 4mm hole is the existing hole, I dont need to clean this up ? all I do is tap the M4 thread to the bottom of the hole ?

Would you consider doing this mod for me if I posted my carb to you and I paid for your services ?
I dont have the tube spacer and you have done this job so many times that I know you would get it done properly.
thanks & regards
Gav

 

[drf256]

I have a question. Does the original nozzle have a hole in the bottom of it to feed it? The new nozzle is devoid of one I see.

So a new nozzle is necessary? This seems akin to the echo 620P carb nozzle if what I am seeing is correct.

Nice thread Randy. Thanks for taking the time.

 

[Mastermind]

thank you kindly for writing this up, very grateful !
I have only one question:

This pilot hole is the right size to run a 4mm bottom tap in to create the threads...

I assume the 4mm hole is the existing hole, I dont need to clean this up ? all I do is tap the M4 thread to the bottom of the hole ?

Would you consider doing this mod for me if I posted my carb to you and I paid for your services ?
I dont have the tube spacer and you have done this job so many times that I know you would get it done properly.
thanks & regards
Gav

The pilot hole is a bit odd shaped near the bottom. So yes, in order to get the pilot all the way to the bottom, it does need cleaned up. I was just trying to keep the instructions very simple and basic.

Yes....I would do your carb. Send me a message.

I have a question. Does the original nozzle have a hole in the bottom of it to feed it? The new nozzle is devoid of one I see.

So a new nozzle is necessary? This seems akin to the echo 620P carb nozzle if what I am seeing is correct.

Nice thread Randy. Thanks for taking the time.

There is no feeder hole in the base of the nozzle. It has two holes in the groove to feed it. If you can remove the original nozzle without damaging, you can reuse it.

 

[Racer]

Hello all. I have questions. I have old husqy 3120 and old carb without H hole like in 1st post this thread. I can modified this carb and added H jet or need like 1st post?