Author Topic: IT 250G Jetting specs  (Read 4529 times)

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Offline William Doe

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IT 250G Jetting specs
« on: April 22, 2015, 02:33:22 pm »

As per title
Could anyone tell me the std jetting (inc carb size and model if possible ) for an IT 250 G

Thanks Bill




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Offline Viper666

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Re: IT 250G Jetting specs
« Reply #1 on: April 22, 2015, 04:31:10 pm »
Carby same size as many IT & YZ 250 & 400 465 etc. VM38SS

Looking from the reed valve side you should see 3R7 stamped near the choke plunger but really this means nothing as Yamaha used the same carby for IT & YZ 250, 400, 425, 465 & even 490's. Just the jetting & slide cut away that was different

Main #350 (340 or 360 alt) Pilot #70 Needle jet P-4 Needle 6F15-3 Slide no.2 cut away but a 3 will work if jetted right.

Parts catalog  http://www.shimwellsyamaha.co.za/images/photos%5CIT250%271980.pdf
« Last Edit: April 22, 2015, 05:02:22 pm by Viper666 »
Thank the Lord for Melbourne Bitter, anti-inflamatory drugs & an understanding wife.
YZ80H, YZ100G, YZ125E, YZ125F, YZ125G, YZ250D, YZ250E, YZ250F, YZ250G, YZ250H, YZ400F, IT125G, IT250K & a, a, a,      CRF250X???????    

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Offline William Doe

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Re: IT 250G Jetting specs
« Reply #2 on: April 22, 2015, 11:03:56 pm »
Thanks Neal appreciated Bill  :)
Its only old bike racing FFS get over yourselves





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Offline yamaico

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Re: IT 250G Jetting specs
« Reply #3 on: April 28, 2015, 11:50:49 am »
Not 100% sure Bill, but I thought that the IT250 used a VM36 carbie, with the jetting detailed by Neal. Happy to be proved wrong, of course  ;D
Pete.

Offline Viper666

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Re: IT 250G Jetting specs
« Reply #4 on: April 28, 2015, 02:36:26 pm »
Quote
but I thought that the IT250 used a VM36 carbie

So did I but that was the info I found but like you I'll stand corrected.

I have an IT250K at home I'll see what it is
Thank the Lord for Melbourne Bitter, anti-inflamatory drugs & an understanding wife.
YZ80H, YZ100G, YZ125E, YZ125F, YZ125G, YZ250D, YZ250E, YZ250F, YZ250G, YZ250H, YZ400F, IT125G, IT250K & a, a, a,      CRF250X???????    

How the FUG did that sh*tbox Honda get in here?

Offline cr4ever

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Re: IT 250G Jetting specs
« Reply #5 on: April 28, 2015, 06:22:36 pm »
http://www.yamahait.com.au/forum/index.php/topic,18926.50.html

IT 250H and J had a VM36SS Mikuni unique to Yamaha, with unique needle and needle jets that are almost unobtainable. Not sure about G.......
OE specs are:
Main jet: 400
Pilot: 50
Needle: 6F34-3
Needle jet: N-8
Slide: 2.0
According to the link above, 6F4/P6 is reasonably close......some great work has been done there......