38mm carbs on my Kat 1100

[Tuna11]

Okay I have a set of 38mm Carburetors that I would like to use on my Kat. I have read the treads of others that have attempted this ,but having issues with the intake boobs being misaligned on the intake port, Or in my case two boots that fit and two that did not. I guess my question is are 38 mm Carburetors applicable to a Katana 1100? IE Which intake boot will lineup on the head, Or is there a 36 mm alternative? Your input is desperately appreciated thank you.

[Kreylyn]

Okay I have a set of 38mm Carburetors that I would like to use on my Kat. I have read the treads of others that have attempted this ,but having issues with the intake boobs being misaligned on the intake port, Or in my case two boots that fit and two that did not. I guess my question is are 38 mm Carburetors applicable to a Katana 1100? IE Which intake boot will lineup on the head, Or is there a 36 mm alternative? Your input is desperately appreciated thank you.

What brand/type 38mm carbs? Important to know.


Yes, there are 36s that have/could be used with the 1127 engine. Either the BST or flat sides if avail.


Krey

[Tuna11]

What brand/type 38mm carbs? Important to know.


Yes, there are 36s that have/could be used with the 1127 engine. Either the BST or flat sides if avail.


Krey

They are RS38-D19-K.

[Kreylyn]

They are RS38-D19-K.

Before purchase, you may want to confirm...


But the gsxR 1100s and 750s used boots that are supposed to be compatible with the 38mm flatsides. The engine port spacing is the same, so it's the boots that need matched up.


Krey

[Tuna11]

Before purchase, you may want to confirm...


But the gsxR 1100s and 750s used boots that are supposed to be compatible with the 38mm flatsides. The engine port spacing is the same, so it's the boots that need matched up.


Krey

That part I know what I need is a part number for the boots. That is the desperately part.

[Wild-Bill]

You're going to lose a lot of torque going with the bigger carbs and I doubt you'll gain much HP in return. Just a thought...

[Tuna11]

You're going to lose a lot of torque going with the bigger carbs and I doubt you'll gain much HP in return. Just a thought...

Ok I came across a set of 34mm RS's on eBay you think they will work better?

[arsenic]

You're going to lose a lot of torque going with the bigger carbs and I doubt you'll gain much HP in return. Just a thought...

I disagree with this whole heatedly. Bill, I fully understand where you are coming from. In general the smaller the carburetor bore, the more torque. Carburetor size goes hand and hand with piston bore size. A 750 uses 36mm carbs and it has a smaller piston bore than an 1100. Why the Katana 1100 uses 34mm carbs, I have no idea. The GSX1100G has the exact same engine and uses 36mm carbs stock. The 90-92 GSXR 750
(smaller piston bore) uses 38mm carbs stock. Using 38mm flat slides on an 1100 will not cause a noticeable loss in torque and it will increase top end. I'm not trying to start an argument, I'm just telling you facts.

[Kreylyn]

That part I know what I need is a part number for the boots. That is the desperately part.

GSXR750 boots, number in bold represents the cylinder it goes too...


13101-17D10
13102-17D10
13103-17D10
13104-17D10

I disagree with this whole heatedly. Bill, I fully understand where you are coming from. In general the smaller the carburetor bore, the more torque. Carburetor size goes hand and hand with piston bore size. A 750 uses 36mm carbs and it has a smaller piston bore than an 1100. Why the Katana 1100 uses 34mm carbs, I have no idea. The GSX1100G has the exact same engine and uses 36mm carbs stock. The 90-92 GSXR 750
(smaller piston bore) uses 38mm carbs stock. Using 38mm flat slides on an 1100 will not cause a noticeable loss in torque and it will increase top end. I'm not trying to start an argument, I'm just telling you facts.

Chris, do you know for sure that the 38mm flat sides will match up with those boots listed above? All information I've researched says yes, but that doesn't replace parts in hand checking I know.


Krey

[arsenic]

No, I do not have any knowledge of what RS carbs fit what intake boots. I've never personally done it. I didn't mention anything about the boot. I just know using 38mm carbs on an 1100 won't cause a negative loss in torque.

[Tuna11]

GSXR750 boots, number in bold represents the cylinder it goes too...


13101-17D10
13102-17D10
13103-17D10
13104-17D10





Thank you I will try these the ones that I purchased are 17E0. There's another guy on the boards doing the same thing he had the 17C0 boots.

Chris, do you know for sure that the 38mm flat sides will match up with those boots listed above? All information I've researched says yes, but that doesn't replace parts in hand checking I know.


Krey

Thank you.I will try these the ones that I purchased are 17E0. There's another guy on the boards doing the same thing he had the 17C0 boots that did not line up.

[Kreylyn]

Thank you.I will try these the ones that I purchased are 17E0. There's another guy on the boards doing the same thing he had the 17C0 boots that did not line up.

You may be able to find some who have done this on the GSXR boards, and perhaps they can confirm those are indeed going to match.


KRey

[Wild-Bill]

I disagree with this whole heatedly. Bill, I fully understand where you are coming from. In general the smaller the carburetor bore, the more torque. Carburetor size goes hand and hand with piston bore size. A 750 uses 36mm carbs and it has a smaller piston bore than an 1100. Why the Katana 1100 uses 34mm carbs, I have no idea. The GSX1100G has the exact same engine and uses 36mm carbs stock. The 90-92 GSXR 750
(smaller piston bore) uses 38mm carbs stock. Using 38mm flat slides on an 1100 will not cause a noticeable loss in torque and it will increase top end. I'm not trying to start an argument, I'm just telling you facts.

GSX1100G - 36mm carbs - 99Nm Torque
GSX1100F - 34mm carbs - 112 Nm Torque

A 2mm (6%) difference in carbs loses 13 Nm (12%) of torque.
qed

nb: Camshafts are not the same and the G only puts out 94 HP versus the Kat's 136.

http://www.motorcyclespecs.co.za/model/suzu/suzuki_gsx1100f%2088.htm

http://www.motorcyclespecs.co.za/model/suzu/suzuki_gsx1100g%2091.htm

[1100]

GSX1100G - 36mm carbs - 99Nm Torque
GSX1100F - 34mm carbs - 112 Nm Torque

A 2mm (6%) difference in carbs loses 13 Nm (12%) of torque.
qed

nb: Camshafts are not the same and the G only puts out 94 HP versus the Kat's 136.

http://www.motorcyclespecs.co.za/model/suzu/suzuki_gsx1100f%2088.htm

http://www.motorcyclespecs.co.za/mod...1100g%2091.htm

I think gearing can replace the loss

[92xjunker]

Gearing a can't replace the loss, it's a give and take thing on gearing, better torque less top end. Smaller carbs is a known way of building torque.