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Main Area => General GS500 Discussion => Topic started by: Sahtlinurk on December 19, 2017, 10:26:38 AM

Title: main jets
Post by: Sahtlinurk on December 19, 2017, 10:26:38 AM
Hi,

Just received couple of main jets for my bike but they seem to be smaller than originals. head is only 6mm instead 9. etc.
apparently they are  "small" main jets. Didn't even know that there are two types. Now, will they fit or shall i send them back? 

cheers,
Lauri
1992 GS500E
Title: Re: main jets
Post by: mr72 on December 19, 2017, 10:33:41 AM
the outside diameter of the head of the jet doesn't matter, strictly speaking, as long as the other dimensions are correct.

A 125 jet for example is 1.25mm diameter (the hole in the middle), as long as the needle goes into it and it's the right inside diameter, right height and depth, then it will work fine.

IMHO, Buddha will be around in a minute to correct me  ;). But I wonder how you got the wrong ones. Hopefully you didn't get Mk2 carb "mid" jets instead of Mk1 carb "main" jets.
Title: Re: main jets
Post by: Sahtlinurk on December 19, 2017, 11:03:35 AM
Got them from wemoto.com . I put my bike's model and year in and it listed me the jets i bought. after receiving them got suspicious and did a web search, discovered they are the smaller version of the two.

Lauri
Title: Re: main jets
Post by: The Buddha on December 19, 2017, 12:13:26 PM
For a 89-00 bike you need large round slotted mikuni (I think they're 8mm dia head).
The small ones are for 01 and later.
This is precisely why I sell jets, mains interchange and work fine with numbers making some sense. But pilots do not. You cant run 01+ pilots in a 89-00 carb and vice versa.
Cool.
Buddha.
Title: Re: main jets
Post by: Sahtlinurk on December 19, 2017, 12:43:31 PM


Ok. thanks.

Lauri
Title: Re: main jets
Post by: J_Walker on December 20, 2017, 09:00:53 AM
I have "large" mains in my 05 carbs and "small" mids. [+ 01 pilots however] the large mains look exactly the same.. maybe they aren't but they look no different, just bigger.
Title: Re: main jets
Post by: The Buddha on December 20, 2017, 09:07:53 AM
Quote from: J_Walker on December 20, 2017, 09:00:53 AM
I have "large" mains in my 05 carbs and "small" mids. [+ 01 pilots however] the large mains look exactly the same.. maybe they aren't but they look no different, just bigger.

Oh wow, you've bass ackwarded it there. Most people end up putting the smaller ones in the 89-00 cos of late that's the common error the clueless parts Idiots seem to make.
I believe the hole dia in mm is what it signifies, so a 125 large round = 125 small round so its fine there.
Cool.
Buddha.
Title: Re: main jets
Post by: J_Walker on December 20, 2017, 09:16:54 AM
Quote from: The Buddha on December 20, 2017, 09:07:53 AM
Quote from: J_Walker on December 20, 2017, 09:00:53 AM
I have "large" mains in my 05 carbs and "small" mids. [+ 01 pilots however] the large mains look exactly the same.. maybe they aren't but they look no different, just bigger.

Oh wow, you've bass ackwarded it there. Most people end up putting the smaller ones in the 89-00 cos of late that's the common error the clueless parts Idiots seem to make.
I believe the hole dia in mm is what it signifies, so a 125 large round = 125 small round so its fine there.
Cool.
Buddha.



I knew better, I was just curious as to what the "large" ones where and what made them different. so I ordered them.  :icon_twisted: I used the ol' eyeball calipers to measure them out. lol I gotta get new ones anyway I got a little excited on the mains and run a bit rich, ironically enough I run lean on mids [causes a weird effect] and will be ordering smalls. since I'm just ordering singles and not whole packs of 4. lol
Title: Re: main jets
Post by: The Buddha on December 21, 2017, 05:08:56 AM
Quote from: J_Walker on December 20, 2017, 09:16:54 AM

I knew better, I was just curious as to what the "large" ones where and what made them different. so I ordered them.  :icon_twisted: I used the ol' eyeball calipers to measure them out. lol I gotta get new ones anyway I got a little excited on the mains and run a bit rich, ironically enough I run lean on mids [causes a weird effect] and will be ordering smalls. since I'm just ordering singles and not whole packs of 4. lol

Meeh, Potato, main jet same thing. Now the mids are also main jets (small round slotted - just smaller holes) but I've never managed to find 62.5's in that. 65 works OK but sometimes its too rich but you can always cover that by not putting the washer under the needle.
Cool.
Buddha.
Title: Re: main jets
Post by: J_Walker on December 21, 2017, 06:57:42 AM
Quote from: The Buddha on December 21, 2017, 05:08:56 AM
Quote from: J_Walker on December 20, 2017, 09:16:54 AM

I knew better, I was just curious as to what the "large" ones where and what made them different. so I ordered them.  :icon_twisted: I used the ol' eyeball calipers to measure them out. lol I gotta get new ones anyway I got a little excited on the mains and run a bit rich, ironically enough I run lean on mids [causes a weird effect] and will be ordering smalls. since I'm just ordering singles and not whole packs of 4. lol

Meeh, Potato, main jet same thing. Now the mids are also main jets (small round slotted - just smaller holes) but I've never managed to find 62.5's in that. 65 works OK but sometimes its too rich but you can always cover that by not putting the washer under the needle.
Cool.
Buddha.

62.5s are sold by JetsRUs [however i'm still salty about the lack of disclaimer originally years ago.- its there now that all I'm gonna say]