TOPIC:

A recent picture here and many threads here and elsewhere regarding bent rods from cyl. Fuel-lock gave rise to this idea. Here's some photos of a carb-bowl over-flow I just installed on my own '80 carbs. Bench testing was accomplished with an actual body & bowl. The final location of the over-flow tube was determined by testing various outlet locations and various carb-body angles, fuel levels and needle-valve flow rates. I was satisfied enough to proceed.
NOTE: Something became very apparent when testing my design. Neither my design nor a "factory" over-flow is capable of draining any bowl which is flooding due to maximum fuel flow through a wide open needle-valve. Clearly, by virtue of the factory design which has a restricted opening, the purpose of the over-flow is to deal with a defective Fuel-valve,needle/seat or O-ring which is "leaking". My full-open tube design should inherently out-flow more fuel in this case and is less prone to plugging as it has no tiny "metered" inlet as is the case with most of the factory designs I looked at.
There are some obvious differences between my design and typical overflow tubes. Whereas the standard location for an over-flow is the center of a float-bowl, the single float location and unique bowl design of the Mikuni BSW32's forced an alternative location.
1) My over-flow is on the left side of each carb. This is the "high" fluid side when the bike is on the side-stand.
2) The tube is installed in the base of the carb-body, not the bowl.
3) The 1/8"brass tube I've used is not "metered". It is full open diameter. I believe the intent of reducing (metering) a drain tube is to reduce fuel loss when the fuel sloshes around. My higher location in the body seems to deal with this while providing a faster rate of drain, if needed. That's my theory, anyway. The final discharge location is optional but common sense must prevail.
Several details need to be emphasized, given the way I proceeded:
1) You must use a brand new "sharp" drill. I chose not to "center-punch" a starting point for obvious reasons. The new drill dealt with this omission easily.
2) Block-up the carb-body solidly so one hand can hold it securely. I used a drill-press. Hand-drilling should work satisfactorily.
3) The point of the drill is not going to make 360 contact initially due to the angle of the body where it is being drilled. A sharp drill with very little contact pressure will "mill" the high-side until the drill point is making full contact. If you force the starting procedure the drill will skip-off. The location of the drilled hole is critical.
4) Using a 1/8" bit for 1/8" tubing gave me a loose fit. This was desirable so the tube would have an epoxy coating inside the hole. Additional epoxy was used inside the body for strength, and I believe is required. Note the left and center carb drain is angled forward. This was strictly for esthetics to minimize the "clutter" under the carbs.

As with anything involving gasoline, Implement at your discretion.

The '79 carbs have been removed and the '80's with the drain have been installed. Once the carbs were syn'd i went for a ride around the block. Riding, on the center-stand or the side stand - All appears OK. Any further pros or con will be posted.

I'd love to sit down with you and have a coffee and really pick your brains
I watch your posts and you come up with more Idea's then Carter has pills (yes I'm that old hahaha)
When do you ever find time to work?
Or don't you sleep.

If you ever decide to put all your kz1300 projects, thought's and fix's into a booklet I'll be one of the first in line.

I'd love to pick my brains too - All those little voices. And I believe I met "Carter" once !

I'm flattered but as I keep saying: Just an ordinary guy with an over active imagination and an ability to see things from a different angle.

I feel the same of those who've got the experience required for splitting the cases. Never had mine apart and the thought of having to, bothers me.

Got to go - i think I'm having an idea.