1980 GS850 Carb issue

[Fer_gloko]

I got the bike in December it was never running 100%, after clening the carbs i discovered the previous owned had put a DynoJet kit stage 3, going from 115 main jets to 165, huge jump,  I've been trying to do a trial and error since the bike is running extremely rich and my spark plus get fouled really fast.

I tried going down to 150 main jets, and 140, still running like shit.

I want to go back to 2 over on the main jets, i want to know if Suzuki goes up 2.5 or 5 increments?

stock is 115, should i go to 120, or 125?

 

 

Edited July 24, 2015 by Fer_gloko

[minx]

Hi - welcome to the site.

Have you got a rolling road near you? As you've discovered, guess work will get you so far but you can end up going around in circles. It's not just about the main jet size.

Failing that, go back to standard settings and work from there. Are you running the original airbox?

 

[Fer_gloko]

No I have K&G pod filters, and 4 into 1 exhaust 

[dago]

dyno jet and mukini are sized differently a 150 mikuni is not the same as a 150 dyno jet  heres a link for a jet size comparison http://www.jetsrus.com/FAQs/FAQ_mikuni_vs_dynojet_vs_keihin_sizes.htm

[gsx]

Just book marked that , handy bit of info 

[wraith]

I take it that you're on CV carbs. I start with 130 main Mikuni jets and the needle in the middle groove, but before you start make sure that the carbs are good and clean as a bit of dirt can give you lots of problems. Also, make sure that you balance the carbs each time you've had them off.