Re Jetting

[ChemDog]

Had another thought.  So busy with training I cant remeber everything I wanted to ask while I was typing.  I am going to tackle the carb rebuilds in the next couple of days and was woundering if anyone knows what jets I would need for the mods on my bike.  It has a wileyco exhaust and a k&n lunch box.  I dont know if the po changed them out already or not.  What numbers on the jets would I be looking for??

[Paulcet]

http://beergarage.com/GSMatrix.aspx

And check the wiki.  The Buddha can get you the jets, or you can order from the supplier listed in the wiki.

Suggest you replace the bowl screws made of parmesan cheese with socket head cap screws. Then you can change jets without removing carbs.

[tb0lt]

You could shoot in the dark, work with something that worked for someone else, hope a suggested setup works... OR do what i'm doing. Drill out 2 holes in your exhaust, weld in o2 bungs and get real time A/F ratio readings from an o2 sensor and properly jet up/down based on what is actually going on with the specific bike.

PS: Paul is right about the carb screws, the original ones are a major PITA and they strip easy.

[skirecs]

don't take the jetting matrix as law though, its an imperfect science, the only way to do is to try a little

the matrix said 150s for me, and it was way rich, so i drilled my 122.5s to 1.39 on the lathe, and it seems to be pretty good


so get the jets the matrix say and start experimenting

[ChemDog]

Awsome.  Thanks to all

[The Buddha]

don't take the jetting matrix as law though, its an imperfect science, the only way to do is to try a little

the matrix said 150s for me, and it was way rich, so i drilled my 122.5s to 1.39 on the lathe, and it seems to be pretty good


so get the jets the matrix say and start experimenting

If you're running pipe and K&N and 150 is too rich and 139 is right one of these 2-3 things has to be happening.
1. Something is clogged in the pipe.
2. Your float level is high. I'd say it would ahve to be high enough to smell like gas on hard acceleration, cos its likely spilling into the air box.
3. You have a worn (dont laugh I know of geniuses who have shaved their needle) or otherwise non stock needle.
4. Leaky emulsion tube O rings.

Cool.
Buddha.

[The Buddha]

don't take the jetting matrix as law though, its an imperfect science, the only way to do is to try a little

the matrix said 150s for me, and it was way rich, so i drilled my 122.5s to 1.39 on the lathe, and it seems to be pretty good


so get the jets the matrix say and start experimenting

Hey skirecs - didn't I send you something a few months ago ? PM me. I forget what we did.
Cool.
Buddha.

[skirecs]

don't take the jetting matrix as law though, its an imperfect science, the only way to do is to try a little

the matrix said 150s for me, and it was way rich, so i drilled my 122.5s to 1.39 on the lathe, and it seems to be pretty good


so get the jets the matrix say and start experimenting

If you're running pipe and K&N and 150 is too rich and 139 is right one of these 2-3 things has to be happening.
1. Something is clogged in the pipe.
2. Your float level is high. I'd say it would ahve to be high enough to smell like gas on hard acceleration, cos its likely spilling into the air box.
3. You have a worn (dont laugh I know of geniuses who have shaved their needle) or otherwise non stock needle.
4. Leaky emulsion tube O rings.

Cool.
Buddha.

I reset float heights (see thread http://gstwins.com/gsboard/index.php?topic=54822.0 ), I would think stock needle but after 21 years who knows, oring i would have to guess is the culprit if there is one.

I just replaced the needle valve seat orings, as the seat came out in my hand and the oring was disintegrated so I suspect them