Vance Hines ss2 r exhaust question

[marmarkus2006]

Just a question for someone in the know about these things. I bought a '95 750 and upgraded the air filter, rejetted, and added the Vance Hines ss2 r 4 to 1 exhaust, Seems to be quite nice. In fact I was so happy with my first Kat I bout another one. Well actually, a Pre 600 complete minus engine and a 98 750 engine. My question is this, I like the look and sound of the Vance Hines ss2 r. Do I have to rejet for that exhaust?

[Wild-Bill]

Shouldn't have to but you'll want to adjust the A/F screws to 2.5 turns out and you might want to shim the needles a hair, depending on how your mid-range is. (Make sure you've got good silencer packing before you make any changes. That'll affect the lean/rich condition.)

[Kreylyn]

A "jet kit" is simply a box of parts that when used enables you to adjust the fuel/air mixtures across all rpm ranges fort he performance, components, and application your using the bike for.

Stock settings are generally lean. Any aftermarket exhaust of filters will further lean that air/fuel mixture out.

It's possible to make some adjustments with out a jet kit to counter this, but a quality jet kit just makes it much much easier to tune and have opperating right.

Honestly, I would suggest a factory pro stage 1 jet kit for stock airbox/exhaust setups with todays fuel. Swapping in any aftermarket ehxuast just furthers the need in my opinion.

Krey

[marmarkus2006]

Thanks for the advice... I was just trying to see if I could get away without it but looks like I might as well just go ahead and do it.

[Wild-Bill]

I ran a 750 for 4 years with a Yoshi can, GSXR 4-1 header and stock jetting. No, I didn't have any lean-popping, mid-range stumble or hard starting. I had the A/F screws set at 2.5 turns out, the idle circuits spotlessly cleaned and fixed every intake air leak I could find.

[Jimmie]

I see many notions on the forum about shimming needles in the carbs. Is this because the US spec carbs doesn't come with adjustable needles to start with, or because the steps for the e-clips on the needles are too big?

[steves]

The US carbs do not come with adjustable position needles unless you purchase an aftermarket jet kit.

[Jimmie]

The US carbs do not come with adjustable position needles unless you purchase an aftermarket jet kit.

That clears is it all up then. Euro spec ones come with 5 positions, makes it a breeze to adjust needle position. But the shape of the needles have always puzzled me a bit, when comparing to other carbs I've had.

[Wild-Bill]

The US carbs do not come with adjustable position needles unless you purchase an aftermarket jet kit.

...and on the aftermarket needles a stainless steel washer will raise the needle almost exactly half a clip position. Sometimes that's all it takes to clear up a mid-range stumble without going too rich. Since it's easy to get at the needles (even with the carbs installed) I like to tune in half-steps once I get close.