Racing idle 1977 GS400

[Guest]

Hi everyone, I recently cleaned my carbs and had to replace the pilot jets but the only jets available were 20 and the stock ones were 22.5. Before I cleaned my carbs I was able to start the bike (with a lot of effort) and it would idle normally at 1,200 RPM. Now with these new jets I can start it fine but it will continue to rev up way past 1,200. Adjusting the idle air screw didn't really seem to help. This lean condition makes me suspect the jets as I looked at the intake boots and they look and feel fine (surprisingly I don't think there are O-rings on the boots? I ordered some to replace, but I could not find any O-rings to replace on the boot, if I am being stupid please correct me.) So I'm pretty sure it is these jets being too small, and considering I can't find the proper ones (22.5 N151.067) should I skip to the next available size 30, or should I try to widen these jets with a wire or something. Any advice would be greatly appreciated, I just wanna be able to ride before winter.

 

[rphillips]

Don't think one size on pilot would do anything like that. Be sure there is still free play in throttle cable and choke is completely off.

 

[Guest]

I checked that there was free play in the throttle cable, it's not liking starting without the choke on and dies if i turn the choke off. Could that idle be from the pilot jet being too small and it having pods? (Previous owner put them on)

 

[Guest]

I checked that there was free play in the throttle cable, it's not liking starting without the choke on and dies if i turn the choke off. Could that idle be from the pilot jet being too small and it having pods? (Previous owner put them on)

Actually I looked closer and the throttle cable does look a bit messed up, I'm gonna readjust it again

 

[Guest]

Don't think one size on pilot would do anything like that. Be sure there is still free play in throttle cable and choke is completely off.

Okay i got the throttle cable to be correctly set and it stopped racing to 4k RPM, but it is still running very lean and won't stay running without the choke. Do you think I should jump to a size 30 pilot jet?

 

[Guest]

Don't think one size on pilot would do anything like that. Be sure there is still free play in throttle cable and choke is completely off.

Okay i got the throttle cable to be correctly set and it stopped racing to 4k RPM, but it is still running very lean and won't stay running without the choke. Do you think I should jump to a size 30 pilot jet?

 

[rphillips]

Sorry, I dun'no, I do know going up one size, on pilots, made mine (not GS400) start easier with less choke. Hopefully a more knowledgeable carb guru will chime in.

 

[pdqford]

Where is your fuel level?
You might be able to lower the float adjustment a mm or 2 (which would raise the fuel level in the float chamber) and make it easier for the existing pilot jet to draw in a smidgion more fuel.

 

[Guest]

Where is your fuel level?
You might be able to lower the float adjustment a mm or 2 (which would raise the fuel level in the float chamber) and make it easier for the existing pilot jet to draw in a smidgion more fuel.

I just set it to the stock 26 mm measurement. I will try doing this, thank you!

 

[rphillips]

Wait a minute!!!, Are you sure???? lowering the floats will raise the fuel level??? That don't seem right at all!!! Let me think,, (head scratch, head scratch) If you lower the "measurement", on your ruler, from 26mm to 24mm, you will actually raise the float height and fuel level. If your floats are where the manual says put them...