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XT600 1986 Carb throttle valve needle placement

Posted: Fri Jan 16, 2015 12:22 am
by stubbs
Hey y'all

Brit calling in from Zurich. New to this forum and also new to the XT world.
I bought a 1986 XT600 43F for cheap and reviving it.

I took apart the carburetor and cleaned it so it looks (and feels) brand spanking new (well almost)
I have a problem with the needle and its placement in the primary carburetor throttle valve.

this is how I removed the needle from the valve:
spring - plastic washer - circlip - plastic washer
Image

after putting it back together i noticed the valve not moving well anymore. took it apart again and it turns out the needle was crooked.
checked the need (straight) checked the throttle valve (moving perfectly without the needle)

after examining the throttle valve I noticed this metal plate sitting inside the valve which has a small nipple protruding...
so if there is a washer lying on top of this, the washer wont sit flush, thus the needle will be crooked.
Image

I also noticed that this nipple sits PERFECTLY in the gap of the circlip.
Image

??
so the diagram in the manual also states that there is a washer on the bottom and not the circlip

I am puzzled!?

Re: XT600 1986 Carb throttle valve needle placement

Posted: Fri Jan 16, 2015 1:09 am
by Mezo
Yes the nipple sits in the gap of the circlip :thumb:

Welcome :nannawave:

Mezo.

Re: XT600 1986 Carb throttle valve needle placement

Posted: Sat Jan 17, 2015 3:48 am
by stubbs
hey thanks for your reply!

the pdf seems not much use, because my carb looks different.

and also, the manual says the washer is between the plate (throttle valve) and the circlip
Image

I seriuosly have no clue hats going on here

Re: XT600 1986 Carb throttle valve needle placement

Posted: Sat Jan 17, 2015 6:24 am
by xtrider
I think it's because most needles are not adjustable so don't have the circlip or that pin. In the US anyways only the TT's had them for a couple years.

Re: XT600 1986 Carb throttle valve needle placement

Posted: Sat Jan 17, 2015 7:58 am
by Mezo
xtrider wrote:In the US anyways only the TT's had them for a couple years.
Well there`s your tuning tip for US bikes then :sherlock:

I have also read of a guy fitting a TT carbie on an XT (more power) so that small adjustment would be important then? would that be something to do with emissions?

Mezo.

Re: XT600 1986 Carb throttle valve needle placement

Posted: Sat Jan 17, 2015 1:35 pm
by xtrider
No idea what the idea behind it all was, The TT's were probably planned on needing to be adjusted because of modding and such since it's the offroad model , back in the eighties they were really starting to worry about emissions so they maybe didn't want people playing with the street models.

TT carbs are hard to get here and when they show up they are way over $100, closer to $200usd, Had put washers under mine to do some adjusting but the secondary is kind of restricted .




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