Hi, ive just cleaned and replaced the float needle and seat on my carbs and i put them back in and it was running too rich. i took the carbs back out and set them to the factory setting(they were a few turns out). not the bike has a vaguely brown exhaust gas which indicates too lean right? Is there any easy way or getting this mixture right without spending endless hours/days taking the carbs out, tweaking the screw then putting them back in numerous times? Or would i be best taking this to a garage and getting them to do it and also if so if anyone has done this how much did it set you back?

hi dorris1988, you say you have been removing the carbs just to adjust the mixture srews? there is no need to remove them my friend,the mixture screws are easily assesable  with carbs on the bike.
just use a flathead screwdriver bit,(i mark 1 corner of the bit so i can count how many turns in/out). the mixture screws are just infront of the float bowls towards front of bike.
3 turns out seems to be the norm,just to ritchen up the mixture a little

So just use the little bit of the changeable screw driver. I never thought of that! Absolutely brillient. I've got to take them off because silly me I forgot to clean the choke plungers and setup as it keeps sticking. But 3 turns you say? Ill give it a go as mine on 2 and a 1/4 turns atm. Fingers crossed =D

I havent tried yet but a flex drive or a right angle screw driver (20 bucks on Amazon) would likely work too.

May I also suggest buying jets from Buddha on this forum. Buy whatever he suggests.

Hi dorris

Have you seen this Mikuni carb article?  Awesome writeup by some Yamaha guys.

http://weislake.com/sig/mucker/carb%20tech3.pdf

This book gives a great overall picture:

http://www.google.com/products?q=book%3A+motorcycles+fundamentals+service+repair&hl=en&btnG=Search

Hey BeerGarage, thanks for that link.  That is a really good writeup on carbs.  You are awesome.  I hope to do some carb work over the Winter...

Everyone knows that the stock gs carbs are really lean, but if someone (me) doesnt want to rejet right now, could restrict the air flow alittle more to acheive a better rich-lean balance, without the cost, and without losing fuel milage of a rejet? 

Or would restricting the air hurt the performance?

I guess a more straight question would be is more air and leaner, better for performance than less air but balanced mixture?

Quote from: BeerGarage on October 14, 2009, 09:33:35 PM
Hi dorris

Have you seen this Mikuni carb article?  Awesome writeup by some Yamaha guys.

http://weislake.com/sig/mucker/carb%20tech3.pdf

This book gives a great overall picture:

http://www.google.com/products?q=book%3A+motorcycles+fundamentals+service+repair&hl=en&btnG=Search

No way! that second link (the red book) is the text book for the seniors at my high school its pretty sweet. im gonna take that home with me today to read through.

Brown gas ? OK I barely see the exhaust gas, but chocolate color plugs are actually perfect.

Does that translate to exhaust gas ...  ...

But on a stock bike I'd run a +1 all around. Set floats to stock ...

AKA 89-00 is 125 mains, 40 pilots, 3 turns on mix screws and 1 washer under needles.

And yes thanks for the plug Johnny Ro, I sell em for 25 shipped in US and Outside the US, pretty much add in mail cost ... so its like 27 to most of middle east and possibly most of the rest of the world.

Cool.
Buddha.

Wow beergarage, nice find on that mikuni writeup. really sums up alot of stuff i was questioning 'under the hood' so to speak in the carb.