Help finding 1977 GS400B replacement petcock

[gorillafan208]

Hi, I recently rebuilt my petcock but as with many others, fuel is still leaking out when on reserve or on. I have decided to just let it die and find a replacement for it. Looking at sites like Georgefixs for aftermarket replacements doesn't show any specifically for the 400 but it does have ones for the 450s and I was wondering if these fit the 400s? If anyone has any reccomendations for where to look for OEM replacements or decent aftermarket ones for a 1977 GS400 please let me know!

[Gorminrider]

Hi gorillafan. Gee, looking here, https://www.cmsnl.com/suzuki-gs400x-...el_4430044050/, that might be an oddball-FIRSTLY it's not a vacuum operated one? Am I wrong? The 450 is Secondly you need check the two mounting bolts aren't a different distance apart than the 450 (or the several Suzuki post-1979 bikes that CAN use the same petcock..) Modifying the 450 tap to be NON vacuum is not impossible, but you'd probably want to stay with a simple on-off? though I suppose you could also glue in a small tube into the carb at the intake to supply vacuum too. I'd actually prefer this, myself. (JBWeld, eh?)

So you'll want to think about these before trying it...though, from the sketch on the site, while the mechanism is different, the holes look to be (wild guess!) the same distance as the 450s and a lot of other bikes too. The mounting of petcocks to a tank has pretty basic requirements-room for the filter to go up and room to mount the thickness for threads to take the bolts....
Consider looking for the exact same tap as a 70's era Honda,Kawasaki too. Bike manufacturers tend to job components out to special manufacturers...ie: Hard to find a Japanese Bike that doesn't have STANLEY stamped on the signals and lenses...if you are lucky enough to have a scrapyard with old bikes, you just might spot one..

ADDED: also search the gallery and the site here. There are a few early 4 stroke 400s in the rebuild section.

[gorillafan208]

Hi, sorry I should have incluided that it is a vacuum operated petcock. I think I will make sure the holes are the same distance apart and order a 450 one, and if that doesn't work I guess it's off to the junkyard! Thanks for the advice!

[Gorminrider]

Still curious- is your petcock the one in my link or a different one? The pictured one doesn't show a vacuum line.
If you post a picture of yours, someone here will likely recognize it and give you a better answer.