Author Topic: IT125 carby upgrade  (Read 2565 times)

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Offline frostygt80

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Re: IT125 carby upgrade
« Reply #10 on: June 05, 2010, 07:23:24 PM »
cool I have just bought a flatside mikuni for one of my 400's with a good throttle etc etc should go good.
1971 TM400 widowmaker PE400's want a few more PE400's

Offline coza77

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Re: IT125 carby upgrade
« Reply #11 on: June 05, 2010, 10:54:41 PM »
Shiny





I woudnt say it was expensive either, US$130.


Bob.


bob where are you, please come back
I used to ride all day....now IT takes me all day to ride..
IT175 J
IT200 N
YZ250 H
YZ250 J
WR250 93
DT200
YZ450F
TTR 50
TTR 110
CR125 RD
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KDX 200
FXSTC 1340 Harley 91
POCKET ROCKET

Offline mboddy

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Re: IT125 carby upgrade
« Reply #12 on: April 28, 2013, 01:52:47 PM »
I just fixed all my picture links in this thread. If anyone has problems seeing the pics then please let me know.
Vinduro Penrite Team
1980 IT125G, 1979 IT175F, 1984 IT200L, 1977 IT250D and IT400D

Offline 4V5

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Re: IT125 carby upgrade
« Reply #13 on: April 28, 2013, 02:03:27 PM »
All good! Thanks for that  8)

Cheers!
Leslie
IT465x4 IT400C IT175F YZ465G YZ250C YZ250WR XJ650G RD350LC RD250LCx5 DT175Nx3 TW200x2 DT200L DT200R RT3 RX100G GT80F YZ80L PW50J KH250B1 KZ250D1 PE175C TS250ER TS185ER AG175B AG100

Offline mboddy

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Re: IT125 carby upgrade
« Reply #14 on: December 26, 2016, 08:43:28 PM »
Seeing that I needed to remove the airbox and a lot of other parts to fit the new shock,
I decided to relocate the Lectron so that it fits a bit better.
It is a very tight fit and the airbox was spaced back to make it fit.
I wanted to move the airbox back to it's original position so that I could get the most shock travel.

First I reduced the diameter of the carby spiggot to 40mm in the lathe.
A groove was cut 0.5mm deep and the spiggot length was reduced from 18mm to 15mm.





This allowed it to fit perfectly into the new 1G8 (1976 YZ125X) manifold.
The 1G8 manifold moves the carby closer to the engine and to the left which is all good.
As you can see it all lines up perfectly inside.



I always use Loctite Number 3 to seal the reed block and manifold and Tygon fuel line.



A small bit of fuel line over the adjustable power jet spring holds it snug in place and improves the seal.
The exhaust pipe is still close to the top of the carby on the right hand side
and so I recessed the screw to give a couple of millimetres extra clearance.  



Now it all fits perfectly.


Vinduro Penrite Team
1980 IT125G, 1979 IT175F, 1984 IT200L, 1977 IT250D and IT400D

Offline Martin I Henry

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Re: IT125 carby upgrade
« Reply #15 on: December 27, 2016, 04:19:05 AM »

Top work Mark.

It all fits together very nicely.

Cheers,

Dave R.

Offline Bigshorts

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Re: IT125 carby upgrade
« Reply #16 on: December 27, 2016, 11:01:27 AM »
Great stuff mark well thought through
When someone hands you a flyer, its like they are saying Here, you throw this away.

IT200 IT490 WR2500 IT175G x2  Ariel Red Hunter .. lots of parts unknown

Offline mboddy

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Re: IT125 carby upgrade
« Reply #17 on: November 25, 2017, 09:39:26 AM »
This thread also talks about the Banshee reed modification. The following is an extract from the IT175F Reeds thread that details it.

The Banshee reeds and stops turned up in the post a couple of days ago. I got a great price from boats.net
$us5.44 per reed 2GU-13613-00-00
$us3.94 per reed stop 2GU-13616-00-00

Here are the standard reeds and stops alongside the Boyesen reeds with the modified RZ350 Stops:


Note that the modified stops are opened up much further than the originals.
They may be opened up too far as evidenced by the rough running up top probably due to reed flutter.
I suspect that the smaller lighter reeds may be opening too quickly for the large carby which may be why it is bogging down low.
I'll put the Boyesens aside for the time being and try the other reeds.

Here are the reeds and reed stops. From left to right: Banshee, CarbonTech HT245, Banshee Stops, original Stops, original reeds: 


Here are the Banshee reeds and stops fitted to the IT175F reed block:


The Banshee stops are longer than the original and also allow the reeds to open an extra few millimetres:


Fitting the new setup into a spare barrel shows that the boost port is obstructed and no light gets past the stops.


Compare this with a block fitted with the original reed stops.


So I fitted original stops for the top reeds so that it does not obstruct the boost port.


It does not matter that the top reeds don't open as far because the top of the inlet port obstructs the top reed.
But for the lower reeds the Banshee stops suit the port better and allow the reeds to open further.
Also, because the Banshee stops have the cutouts, the lower reeds should respond quicker.

I started the bike up and warmed it up. It is very crisp. Better than either the original setup or the Boyesen setup.
It sounds great. Revs better than you would expect from a stock exhaust and silencer.
But it felt like it was slightly lean at idle and so I turned the Lectron rod 1/4 turn richer.


A small update to provide an extra option.

On some parts lists the reed block 10V-13610-01 is listed as a replacement. I got a NOS one for about $35 (bargain).
It's reed stop 10V-13616-01 (or 10V-13616-00) looks like a viable alternative to use for the upper reed stop as it is the same size.


The other one that looks viable is the Blaster reed stop 58T-13616-01. But I haven't measured one yet.

Vinduro Penrite Team
1980 IT125G, 1979 IT175F, 1984 IT200L, 1977 IT250D and IT400D