Jetting advice...1982 GS450 TXZ

[Anonymous]

In your opinion what jet sizes would you fit to a 1982 GS450 TXZ with the following mods:

k & N style air filters
2 into 1 aftermarket exhaust

[Anonymous]

bump...

[IanFrancisco]

Stock jets on my '80 GS450ST are 115 and 17.5. The previous owner apparently tried 117.5 mains and went back to stock, according to his notes in the FSM. If you have the same carbs I have there are some spacers that can be removed from the slides to lift the needles. The factory setup was too lean, the PO removed the spacers. I had good idle and good WFO but bad 1/3 to 2/3 throttle range. The only thing I could do was raise the fuel level in the bowls by lowering the float height from 24mm to 22-23mm. Stock exhaust and airbox, but some free-flowing dry element instead of an oiled-foam filter. I might try 117.5 mains...

Checking bikebandit for your year shows the same carbs I have. I'm pretty sure the spacer that was removed is part #11, called a washer in the bikebandit pic.

http://houseofmotorcycles.bikebandit.com/partsbandit/oem_schematic_view~mp_id~~mscssid~27NQDD8XWQ928G1WQB1Q1DWTNB0R1C44~schem_dept_id~993811~section_dept_id~1~section_dept_name~OEM+%28Stock%29+Parts~dept_type_id~2~model_dept_year~1982~model_dept_mfr~Suzuki~model_dept_id~987996~model_dept_name~GS450TXZ.asp#stay

[KEITH KRAUSE]

Just a guess here. Very little experience with that model.
Main jet: 4 full sizes up. (5) is a full size. Example: if 115 stock, try 135's.
Jet needle: if you have a US model, your jet needles aren't adjustable. They need to be raised some. I would guess the equivalent of about 1 1/2 positions of an adjustable needle. That would be around .07". You may find spacers to shim the needles up at a hardware/Radio Shack store.
If you have adjustable needles, I'd try lowering the e-clip 2 positions or try lowering it 2 positions with the above mentioned spacer directly on top the e-clip. This would give you the 1 1/2 position change. A jetting spacer is about .022" thick.
Mixture screw adjustments may be all you need for the pilot circuit. Try an additional 1 to 2 turns out from the factory setting. If still lean, go up 2.5 on the pilot jet.
Vacuum synch the carbs always before testing.

[Anonymous]

Just a guess here. Very little experience with that model.
Main jet: 4 full sizes up. (5) is a full size. Example: if 115 stock, try 135's.
Jet needle: if you have a US model, your jet needles aren't adjustable. They need to be raised some. I would guess the equivalent of about 1 1/2 positions of an adjustable needle. That would be around .07". You may find spacers to shim the needles up at a hardware/Radio Shack store.
If you have adjustable needles, I'd try lowering the e-clip 2 positions or try lowering it 2 positions with the above mentioned spacer directly on top the e-clip. This would give you the 1 1/2 position change. A jetting spacer is about .022" thick.
Mixture screw adjustments may be all you need for the pilot circuit. Try an additional 1 to 2 turns out from the factory setting. If still lean, go up 2.5 on the pilot jet.
Vacuum synch the carbs always before testing.

Thanks guys, that all sounds good to me. PS. Where can I pick up the right jets for those carbs?

[IanFrancisco]

bikebandit or your local Suzi dealer.