My petcock threw up—!

[Vermont4me]

Help please- my 81 xs400 is almost ready for new life- rebuilt carbs, reinstall fuel lines, vacuum line and boom, my petcock is leaking fuel- my bike hasn’t seen oil or car for 30 years so pretty sure the petcock seals are shot- is there an aftermarket petcock anyone can recommend that I can grab fairly quickly?

thx-
Bob

 

[tstidham]

I put a purely mechanical one on my 78 off Amazon. I just posted the link in another thread, I'll see if I can find it.

 

[Vermont4me]

Thank you- being that my vacuum system still works (I think) will it interfere with the operation of the bike that you know if? Cheers

 

[tstidham]

I just capped off the vacuum port on the intake when I switched it. No issues, other then remembering to turn it on and off. I've already started riding a few times with it off and wondered why I started stalling a mile down the road!
This is the one I use:
https://www.amazon.com/Carbman-Petcock-Special-XS1100-447-24500-02/dp/B07SWJ4N9J?ref_=ast_sto_dp

 

[Vermont4me]

When you say ‘switched it’ you mean petcock right? Thx so much btw- it’s a huge help- looking forward to getting my 81 (3300 miles) ON THE ROAD!!

 

[Vermont4me]

Also, I have the original carbs (gummed up but intact…) is there a need for those on this forum? Classifieds? Cheers

 

[tstidham]

When you say ‘switched it’ you mean petcock right? Thx so much btw- it’s a huge help- looking forward to getting my 81 (3300 miles) ON THE ROAD!!

Yes, when I removed the old vacuum petcock and installed this one to the tank.

 

[Vermont4me]

Yes, when I removed the old vacuum petcock and installed this one to the tank.

 

[Vermont4me]

Cool, MANY THANKS

 

[Vermont4me]

If I can ask one final question (mechanic I’m not…) so when I install the new petcock, I simply cap the vacuum nipple that previously had a hose on it to the petcock? Thx

 

[CaptChrome]

If I can ask one final question (mechanic I’m not…) so when I install the new petcock, I simply cap the vacuum nipple that previously had a hose on it to the petcock?

Yes. Install the manual petcock and make sure that both of the vacuum nipples on the carb holders are capped off.

 

[Vermont4me]

Yes. Install the manual petcock and make sure that both of the vacuum nipples on the carb holders are capped off.

perfect- thanks again

 

[Vermont4me]

Wow, what a journey, I (hope) that I’m almost there- new petcock arrived, installed it along with the new-old carbs, gassed it, sprayed the carb cleaner and it FIRED up after 32 years of sitting in a barn (oil is decent etc-) PROBLEM- the right muffler (which was heat colored when I got it..) appears to heat up and actually smoked a bit- have to adjust the idle speed tomorrow but the muffler smirking has me worried (btw, I ‘capped’ the vacuum nipples…) any ideas? Thanks so much!

 

[tstidham]

I would check the valve lash first, then go about setting the idle mixture and idle speed. It may be lean on that side. But great news!

 

[Vermont4me]

Indeed, working on that today- thx for this also

 

[Vermont4me]

Ok my friend, for some reason I feel that you’ve ‘been there’ for this cycle rehab- new wrinkle, bike was running odd (mentioned the gas leak etc) so I removed the carbs (again, and btw, they were originals from eBay in seemingly good shape..)- upon closer examination the float was corroded right thru- question, is there a pair of new aftermarket carbs that you’d recommend I can snag to get this baby running again-

 

[Vermont4me]

Carbman Twin Carburetor Double Cylinder Carb Compatible with Honda Rebel 250 Carburetor CA250 CMX250 1996-2011 CMX250C 2003-2011 Carbs https://a.co/d/epO5Agv

????

 

[tstidham]

Mikesxs does have a set of mikunis for the xs400 as a kit. I prefer the factory carbs myself. Maybe find some new floats?

 

[CaptChrome]

I second the attempt to source some new(ish) floats for the original BS34 carbs. Other carbs will work, but you will have to be ready to spend a lot of time learning by trial and error to get them dialed in. The flat slides from Mikuni and Keihin are good choices, and there are a bunch of racers who use these on similar displacement bikes, but having carbs that Yamaha engineers already figured out is worth something.

 

[Vermont4me]

Appreciate your time, you have been wicked helpful- so yesterday, yeah, got the bike running and idling smooth but fuel kept rolling out of one side- i even ride the bike, felt good…took the carbs off, then apart and cleaned them, thinking maybe the initial ‘starting’ got em bunked up- put em back together and reinstalled them and didn’t even notice the hole in the float- took them back out and then I noticed- anyway, the seller from eBay was understanding and I really do feel it was an oversight so I found another set, ordered two rebuild kits and had to put off what I wanted to happen yesterday- lol-