Fuel "T" tube leaking

Hi good friends

1981 LTD 750 H1

Just noticed a gas leak at the "T" fuel tube. It doesn't appear to be cracked but fuel is leaking at the area where the tube goes into carb #3. I see there are o rings available for it on partszilla so I plan to order a couple. Does this sound like the fix or is there something else I should be looking at? Also I'm wondering can I keep carb #4 and #3 connected when I take it apart or do they need to be taken apart separately (I've never taken them apart before). Thanks for any and all enlightenment you can provide.

You will have to take the carbs off the rack to remove the T.

O-ring sizes

Pilot Screw: 1.2 x 2.6
Pilot Plug: 1.5 x 2.8
Fuel Transfer Tubes: 2.0 x 5.5
Drain Screws: 1.4 x 4.0
Float Bowl: 2.0 x 67

I think the fuel t and carb fuel couplings o ring size is 2 X 8 for mikuni VM carbs. Not sure what's on your bike?

Warren3200gt wrote: I think the fuel t and carb fuel couplings o ring size is 2 X 8.

O-rings are sized by thickness and ID. 2.0 x 5.5 is the correct size. I buy O-rings in bulk because I restore a lot of carbs for people.

The O-rings on the Tee and fuel transfer tubes get exposed to the outside environment and are the first to get hard and brittle. They typically literally crack and crumble when removing them.

Unganging the carbs is a bit of a pain but necessary when rebuilding a set. The challenge with the CV34's is the choke system. You might want to take photos of the linkages and how that tiny spring fits in the system. I use red loctite on the butterfly screws when replacing them and I also upset the head just like the factory does. I made a small nub by grinding a piece of file, then that gets positioned in the backside of the screw and it gets pinched with high leverage pliers to flare out the end. I've got photos showing the process if anyone is interested.

Nessism wrote: I've got photos showing the process if anyone is interested.

Interested!

First photo shows the nub made from a piece of file stuck to some channel lock type pliers using modeling clay.
Second photo shows screw being flared.
Third photo shows the nub stuck in the back side of the screw after flaring. A pair of needle nose pliers is used to reach inside the carb and remove the nub from the screw.

Thanks Ed. Do you pre-drill the ends of the screws?

Warren3200gt wrote: I think the fuel t and carb fuel couplings o ring size is 2 X 8 for mikuni VM carbs. Not sure what's on your bike?

Keihin CV34

Nessism wrote: O-ring sizes

Pilot Screw: 1.2 x 2.6
Pilot Plug: 1.5 x 2.8
Fuel Transfer Tubes: 2.0 x 5.5
Drain Screws: 1.4 x 4.0
Float Bowl: 2.0 x 67

Thank you good sir. Question, where do you purchase 0-rings in quantity? I know partszilla has them but lordy their prices. I'd love to get a bunch of these sizes for a furture rebuild as I have a spare set of carbs sitting around that I'd like to rebuild to have as a ready spare. Thanks!

I think I’ve heard Nessism mention Cycle o rings

www.cycleorings.com/

Mikaw wrote: I think I’ve heard Nessism mention Cycle o rings

www.cycleorings.com/

cycleorings has kits for Suzuki GS type BS (CV) and VM carbs and most of the sizes will fit KZ version Mikuni's, but not all. It's a good starting place though.

I get O-rings from either McMaster Carr or The O-ring Store. Buna N O-rings are fine, if not preferred for carbs, although some people like Viton.