1990/1992 GSXR 1100 Jetting question.

[Driift]

I just picked up both a 1990 GSXR1100 and a 1992 GSXR1100.

1990 Stock but with California needles and air jet.

1992 Yoshimura full exhaust with stock jets and California needles and air jet.

Question....... I am changing both the air jet to the 1.35 non California jets, and the needles to the 0-8 non califorina on both bikes .... Should I just leave the stock jetting or incease in for the Yosh pipe?  Or do you recommend dynojet stage 1?  Factory pro?

 

Thanks.  

 

Tim

[Evilston3r]

I have always found that the dyno jet kit needles are made from a harder material than the standard,  and can bounce against the main jet and tubes causing them to oval , I heard factory pro kits needles are better but I have never seen any, there was a plan flying around for some top hat spaces that you put in the top of the needles to hold them better in the slides to stop the bouncing around,  I ran 128 mains with a side v and h pipe, which worked well, 

[Upshotknothole]

I've always preferred Factory Pro myself. Might as well leave the stock bike stock if it's running fine. Maybe throw a stage 1 kit in to the one with the Yosh pipe. I'm guessing you're keeping these stock?

[ArcanumOne]

Factory Pro makes very good quality emulsion tubes and needles.  I had issues with the emulsion tubes ovaling-out on my Triumph Speed Triple, Bimota SB6 and my GSXR1100.  I replaced all the emulsion tubes with Factory-Pro's and also replaced all the jet needles with their Titanium needles and have not had an issue since.

[Jaydee]

And upgrade the air filter too. If you're increasing the fuel, you have to increase the air proportionately.  My 1127K, I have a stage 1 K&N single cone filter in my  airbox, stage 1 DJ and 4-1 Akrapovic. Works for me.

[Gixer1460]

10 hours ago, Jaydee said:

And upgrade the air filter too. If you're increasing the fuel, you have to increase the air proportionately.  My 1127K, I have a stage 1 K&N single cone filter in my  airbox, stage 1 DJ and 4-1 Akrapovic. Works for me.

DJ stg 1 kits are designed to work with stock and free flow filters in an airbox so there can't be a huge change. Stg 3 is where the bigger fuel changes occur. Cali bike tuning is a law unto themselves due to the smog bollux added which messes with everything!

[Jaydee]

12 hours ago, Gixer1460 said:

DJ stg 1 kits are designed to work with stock and free flow filters in an airbox so there can't be a huge change. Stg 3 is where the bigger fuel changes occur. Cali bike tuning is a law unto themselves due to the smog bollux added which messes with everything!

Tried it with the stock filter but the K&N was miles better. Found my K was a lot more lively.

[Upshotknothole]

On 6/20/2022 at 10:06 AM, ArcanumOne said:

Factory Pro makes very good quality emulsion tubes and needles.  I had issues with the emulsion tubes ovaling-out on my Triumph Speed Triple, Bimota SB6 and my GSXR1100.  I replaced all the emulsion tubes with Factory-Pro's and also replaced all the jet needles with their Titanium needles and have not had an issue since.

Factory Pro usually only has Mikuni emulsion tubes for the GSXRs if they have any at all. They used stock tubes, custom needles, and Dynojet used their own design for both. 

[Gixer1460]

11 hours ago, Jaydee said:

Tried it with the stock filter but the K&N was miles better. Found my K was a lot more lively.

Don't doubt it - the DJ kit is doing what it's supposed to do - it will work with stock filters but a bit pointless!