GS/GSX 750ES owner with 4-1,Carb question

[Tompasio]

Have anyone changed the exhaust from stock to a 4-1?
Did you have to rejet the carbs and how much?

[Guest]

What type of 4-1.

[Tompasio]

What type of 4-1.

I have a new Marshall Deeptone with stock airbox.

[Guest]

With my Kerker pipe I installed a 117.5 (stock 107.5) and a 47.5 pilot jet (45 stock) with the airbox lid removed.

[Tompasio]

With my Kerker pipe I installed a 117.5 (stock 107.5) and a 47.5 pilot jet (45 stock) with the airbox lid removed.

So in my case i will go 130 (stock 120) an pilot 45 (stock 40)?

[Guest]

So in my case i will go 130 (stock 120) an pilot 45 (stock 40)?

42.5 pilot would be my best guess on the pilot jet.

[Hoges]

I've got a local manufactured aftermarket "Formula One" 4/1 system on my 16valve GSX750SE 84 model, and main jets are 117.5. Excellent at this. I'm at 900metres above sea level.

[Smokinapankake]

So, Hoges, did you not have to up the mains at all, because my 84 GSX 750SE uses 117.5's and it is bone stock.....

[Hoges]

Yep, still std main jets then. Seems to go okay with great mid range. Top speed wise, most I've run out to is 180KPH. There was more to go there, but it was close to topping out I think. Small little furry things that live in the bush here have a habit of trying to cross the road at the same time as when vehicles drive by, so it makes me nervous!