A little help may go a long way,( carb question)

[KatriderBBK]

I have a 95 katana 750 stock. I brought it off a friend. It sat in his in house for two years. HE SAID that the carb were rebuild. After i check. they are in deed rebuild. But i think the guy did them wrong.

Here is my issue. Riding the bike under load it wouldnt go passed 8,000 rpm in any gear. I check the clutch, ok. spark, ok. I am missing the correct clamps on the intake boots, an i notice a small crack on the intake boot, sucking air no dout. and no clamps at all on the airbox side, sucking air too no dout. And I also move the vac line to the petcock from the top of carb #3 to the side of carb #4. Check and fix height on floats. while i was check the floats i notice that the main jet had 135 stamp on them. Now it is a stock bike, no extra. Stock main pilots are 112, Right? pilot screw setting is 2.5 turn out. I move the clip needle from 4th to 3th ring. Still same outcome wont go passed 8000rpm.

So My question is 135 main jet to much for a stock bike. Or can I tune it
Plus I am looking for intake boots and 8 clamps for the front and the back of carbs. and maybe main jets. ANy idea

[DHolzwarth]

You do not have a stock set up for a 95 750F.

Your carbs should Mikuni BST36SS. The needles for these carbs have a fixed setting, no notches.

Jets for 1, 2, 4 should be marked 105. Jet for 3 should be 110.

I'm no expert, but your pilot screws are MUCH farther out than mine. (Just under two out, for the jets listed above. And I just cleaned/adjusted my carbs last month. I'm sure.)

You should have FOUR hoses coming out of the carb set. The shorter, larger ID hoses connect carbs to petcock. The longer, smaller ID hoses are for air vent and do not connect anything. IF you don't have four hoses, that's just more indication that the carbs were rejetted at some time.

You can get the parts from numerous Suzuki OEM part sellers on the web. Before I found this site, I used www.cheapcycleparts.com a lot. Expect a long wait, though.

But there are several vendors who support this site that could probably help you too.

Probably a good time to buy a manual along with the parts.

**** Holzwarth

It's not a bad word, it's my NAME! Please stop *****ing it out!

[KatriderBBK]

Well Then, It has been rejetted. But still doesnt help out on the rev prblom

[Kreylyn]

From http://www.gixxer.com/forums/showthread.php?t=159718

Katana 750 (GSX750F)

1988-1996

Type: BST36SS

Main Jet
U.S , cylinder #3: 110
All others: 105

Main Air Jet: 0.5mm

Jet Needle
California: 5EZ53
U.S except California: 5EZ62
U.K: 5EZ61-3

Needle Jet
U.S: Y-1
U.K: Y-2

Pilot Jet
U.S: 32.5
U.K: 37.5

Pilot Air Jet
1989 and 1990 California: 1.25mm
1991 on California: 1.2mm
U.S except California: 1.35mm
U.K: 1.3mm

Pilot Screw setting
U.S: Preset
U.K: Preset (1 5/8 turns out)

Starter Jet (choke): 37.5

Float Height: 14.6mm (+/- 1mm)

You have several issues going on atm that need to be resolved.

First, you have a stage 3 jetkit (130+ sized mains) installed. This setup pretty much requires you have pod high flow filters to work correctly. The Airbox is too restricting for the fuel you have flowing into the carbs at this time.

Unfortunately, high flow air filters also are extreamly difficult to get everything tuned to run correctly and can in and of themselves cause issues at high rpms.

If your eclips are on 3 or 4, I would think that is a bit rich running to begin with as well.

Has this bike ever run right after they put the "rebuild". I'm betting not, and the reason you now have the problem.

If you want to get it running right, I would suggest doing the following.

1. Change the main jets to 110s with a 112.5 on #3. (stage 1 jetting)
2. Set the E-clips to the 2nd slot from the top.
3. Seal all the vacuum leaks. (this means fix the airbox issues as well)
4. Use an OEM filter in the airbox.

Give this a try and fine tune from there.

Here is a good source of info for tuning the bike.

http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,cv,high_rpm_engines.html

Krey

[KatriderBBK]

Sweet deal. I did replace the main jets today. and holy sh!t there were 175 mains in her. Running much better. Now i need a new air filter and a oil change, spark plug. And FYI bst36ss carbs use small round slotted main jets. So thanks for help people.

[DumbLuck]

Krey was pretty much right on. the only thing i have to add is about the "extra" (other poster, not Krey) hoses. there is a vacuum line from #4 (furthest right) that runs to the petcock to hold it open when the skoot is running. the other 3's vaccuum ports should be capped off. there are 2 vent hoses, i each between 1&2 and 3&4. look up the carb rail on like BikeBandit.com's fiche or look in your service manual to see what's what.

[KatriderBBK]

The hose doesnt go to the top of the carb. The vac line from the petcock runs to the side of carb #4. Should it go to the top. I have pretty much read the manual and i have many hours retry different configs. I think she could use a fine tuned. As far as the hoses between 1&2 and 3&4 are not there. Should i put vent tubes back on?

[kevin2502000]

Petcock hose goes to the side of #4 not on the synch port. The overflow hoses on my bike have been gone ever since I owned the bike, (10 yrs) with no ill effect. They are for dumping fuel if the carbs overflow out onto the ground rather than onto the crankcase. The nipples are split and torn and I don't feel like a separation to fix them. I just rotated them down so they don't catch water.