Don't disturb this carb jet!...I did, now what? 78 GS 750

[Guest]

1978 GS 750 with carb problems. I stripped carbs down for dipping and in the process removed the needle jet inside the bowl just on the airbox side of the main jet. While the parts soaked I picked up the manual for set up specs and noticed that this needle jet is factory calibrated and should not be disturbed. Now what?? Is there a process for re-setting this jet? Is there a default number of turns out from a seated needle? Any suggestions? I'm thinking its an air mixture jet since its just in front of the airbox??!!

I'm new to the forum so thank's in advance for any ideas or suggestions!

[Nessism]

3/4 turn from lightly seated is a good starting point. more info below.

http://members.dslextreme.com/users/bikecliff/

http://members.dslextreme.com/users/bikecliff/images/vm_carb_rebuild.pdf

[Big T]

It's called the pilot fuel screw

[Steve]

Re-reading the original post, it's a bit confuzzling.

He removed "the needle jet inside the bowl just on the airbox side of the main jet.". The only thing inside the bowl is the pilot fuel jet. It should be fully-seated, but it's on the engine side of the main jet and it's not really needle-shaped.

On the outside of the carb, near the airbox are the pilot air adjustment screws. Somewhat needle-shaped, but not "in the bowl, near the main jet". These are adjusted to give best idle, usually about 1 - 1.5 turns out.

Also on the outside of the carb, but hidden on the bottom, closer to the engine, are the pilot fuel screws. Very definitely needle-shaped, but not in the bowl. These are set based on intake/exhaust choices. For stock equipment, about 3/4 turn out from LIGHTLY seated works well.

.

[allojohn]

The air jet is factory set with a blob of white paint. No other jet is "fixed."

[Beech35p]

Upon further review... The needle is the Pilot fuel and is accessible just outside the bowl. The service manual points this out as factory calibrated and permanently set. No paint or sealant is applied so I’m sure these valves have been adjusted by previous owner. I’ll start at 3/4 out and see what happens! Thanks to all!!