[Wild-Bill]

No pic.

Those two lines are vents. They don't go anywhere and I usually just turn them so the openings face down and do without the tubing.

[nedfunnell]

Huh. Well that answers my question, anyway. I tried starting the bike today and it wouldn't, but I smelled gas- so I feel like it is getting some gas at least. The petcock is fine. Could this be an ignition issue?

[Wild-Bill]

Anything's possible. You could check for spark at the plugs but you said your floats weren't sealing correctly. Check by filling the bowls and trying to blow in the fuel lines. If you get air through then they're not sealing. Fix that before moving on.

[itssmeebtchs]

if you have the money arsenic will hook it up.. they look pretty much brand new and work like a charm.. the carbs...

[Kreylyn]

The original problem was starts and runs fine cold, then eventually stops and restart quickly becomes worse and worse till it won't start?

Right?

That says to me you either are not getting enough fuel flow to the carbs and it's running out of fuel, or you have too much fuel flowing (stuck floats) and it's filled the oil.

If not enough flowing, but some is... then you eventually use more than is being replaced and it's essentially running out of fuel in the carbs.

If the floats are sticking, it is flooding the engine and your oil with fuel. Cold engines run better on richer conditions, so it will start up and run fine. But as it warms up, it starts to flood out as a hot engine runs better lean. Gas in the oil will flood the engine.

A full carb cleaning is the most likely resolution, followed with checking petcock and fuel lines are right and flowing/no kinks. Change the oil after you fix the carbs if there is fuel in it.

Carb cleaning is much more intensive than opening the covers and spraying with aerosol carb cleaner spray. There most times need to be a carb cleaning dip, an ultrasonic cleaner, media blasting, or something more than just the spray to really get them clean enough.

If you have them super clean and the float needles still won't seal, you may need to replace them.

I don't think it's an ignition problem....

Krey

[nedfunnell]

I think I figured out a big part of my problem. When cleaning the needle seats, I looked at the o-rings on them and I think they're completely shrunk. I got to the second carb with cleaning and stopped, because when I put it back in to the carb body, it just slid right in and clicked when it hit the bottom, indicating that the o-ring wasn't touching at all. Here's a picture of what I'm talking about: http://www.majhost.com/gallery/Ned/Katana/img_0965.jpg (Warning- full size pic)

As I mentioned above, I think my bowl O-rings have the same issue, another pic: http://www.majhost.com/gallery/Ned/Katana/img_0967.jpg (Warning- full size pic)

Could someone confirm that these o-rings are shot, and I'm not mistakenly replacing things I shouldn't mess with? Also, could someone point me to a source for these O-rings? The Carb Kit Capital link above is OOS. I may just get some same-sized generic Viton o-rings from McMaster. Has anyone done that before?

[kevin2502000]

Yes you can use generic o-rings, replace them, they are old anyways and it's like 30 cents a piece.

[arsenic]

You haven't ordered o-rings from McMaster-Carr have you? You have to order a pack of 25. Vitron are packs of 25, Buena-N are packs of 100. Still only like $8 though.

[nedfunnell]

You haven't ordered o-rings from McMaster-Carr have you? You have to order a pack of 25. Vitron are packs of 25, Buena-N are packs of 100. Still only like $8 though.

I was just looking at materials. I knew rubber would be out, an the McMaster applicability chart shows only PTFE, Kalrez, Fluorosilicone, and FEP has having both good gasoline and alcohol resistance- Viton is shown as 'poor' alcohol resistance so I counted it out. Have you used Viton with good results in E10 fuels? Do you have a box of these sitting on a shelf, so I could just buy 5 from you cheaper than McMaster?

[kevin2502000]

Hardware store, metric orings or harbor freight.

[arsenic]

Yeah, I have them. I use Viton o-rings for ALL the float bowl o-rings, Have been for about two years. No complaints.

[arsenic]

harbor freight.

I'll pass, I prefer my stuff too actually work.

[nedfunnell]

Hardware store, metric orings or harbor freight.

Kevin, have you used those with gas/E10 with success?

[nedfunnell]

So how much for a set of O-rings for the BST31SS carbs?

[arsenic]

PM me