Float adjustment. Isn't there a write on how to use the clear tube method

I've searched, but can't come up with what I'm looking for. I think I'm just not putting in the right phrase. I could have sworn I read a good write up on how to use the clear tube method.

Can you guy's point me in the right direction. Thanks

It's really simple. It's just a measurement to see if your float bowls are filling enough, or too much.

1: get some clear tube that fits well on the drain. Probably get 2 of them, so you can do both bowls at once, to compare the heights.

2: put the bike on the center stand, so it's level

3: put one end of the tube on the drains, other end above the float bowl level

4: open the drains so fuel flows into the tubes

5: turn on the petcock to let fuel flow. maybe start the bike if necessary.

6: observe the height of the fuel. Is it over the top of the float bowl gasket? if yes, then your floats are too high, or the float valve is leaking. Is it the same in both bowls? if no, then you will need to adjust one or both floats.

make sense?

I don't have drain's on my 72.

So I guess I'm going for the M8x1.0 grease fitting.

This may make me sound dumb,,, but I gotta ask. I assume I have to block off the fuel line that balance's the 2 carb's, the one the blue arrow is pointing to. Isn't the purpose of that hose to balance the fuel level. Should I block it off.

Also. What about the fuel line that connects the choke bodies together. Should it be blocked off as well.


I forgot who's pic this is,,, but I hope you don't mind.

I did the first side and all went well. When I was screwing in the grease fitting into the second side,, I broke the bowl. I didn't even tighten it that tight. I don't get it. I realize this is a tappered thread,, and I did not go very tigh at all.

Well. I guess I went tight enough to break it. The only thing I can think of is I used too much teflon tape. IDK!!

Here it was done with some electrical tape around clear tubing to make it fill the hole. It may be a caveman method, but it works, and does so without doing any damage.

Wow, Marty has quadruplets!
Ok, Cal, I photoed page 72 from the factory manual, and pics of my barbs. The manual calls-out 4mm from carb lip, different from posts in this forum. I've gotten along fine using 3mm (1/8"). If the pics aren't clear enough, check my gallery 'carb checkers'...

TwoManyXS1Bs said:

Wow, Marty has quadruplets!
Ok, Cal, I photoed page 72 from the factory manual, and pics of my barbs. The manual calls-out 4mm from carb lip, different from posts in this forum. I've gotten along fine using 3mm (1/8"). If the pics aren't clear enough, check my gallery 'carb checkers'...

Click to expand...

So ummmm... Where did you get those fitting's.

Sorry, Cal. Guess I cheated.
Atlas lathe, don't leave home without it...

TwoManyXS1Bs said:

Wow, Marty has quadruplets!
Ok, Cal, I photoed page 72 from the factory manual, and pics of my barbs. The manual calls-out 4mm from carb lip, different from posts in this forum. I've gotten along fine using 3mm (1/8"). If the pics aren't clear enough, check my gallery 'carb checkers'...

Click to expand...

If you check the SJ/SK factory manual. Section 4 page 6.
It calls for only +/- 1mm. Different from your manual. And maybe what you have seen referenced.
They do reiterate the need to use a tubing of 6mm/.24 ID on the hose.
But what do these stinking manuals know.
I could take a photo and post but I would denying you the chance to "look it up yourself". Cause I get TIRED of retyping things. But I will take the time to type the fact that I WON'T retype it. Here is where the posse joins the fun. Welcome to the garage recreated.

TwoMany, reread your manual: it calls for a fuel level 4 mm. below the carb body gasket surface, not 4 mm. below the lip of the carb body. Wanna find out where that puts things when you look at the outside of the float bowl? Scribe the bowl along the overhang of the carb body, drop the bowl, and measure from the line to the top of the gasket. It's going to put you very close to the edge of the carb body flange that overhangs the float bowl. Weekendrider, tuning range is +/- 1 mm. from the midpoint setting, not +/- 1 mm. of the gasket surface. If you go +1 mm. from the gasket surface you'll find fuel in the vent lines.

TwoManyXS1Bs said:

Wow, Marty has quadruplets!
Ok, Cal, I photoed page 72 from the factory manual, and pics of my barbs. The manual calls-out 4mm from carb lip, different from posts in this forum. I've gotten along fine using 3mm (1/8"). If the pics aren't clear enough, check my gallery 'carb checkers'...

Click to expand...

It says it the first photo that the tubing has to be 2.5mm. Does it have to be 2.5mm or at least 2.5mm? I see alot of guys using 1/4 fuel line in the pics.

hard_y_rd said:

It says it the first photo that the tubing has to be 2.5mm. Does it have to be 2.5mm or at least 2.5mm? I see alot of guys using 1/4 fuel line in the pics.

Click to expand...

Yeah, pondered on that, too. Many years ago, in chemistry class, we were taught how to read the 'meniscus' of a fluid in a tube, the concave shape of the fluid surface caused by surface tension with the tube walls. The rule was to read the bottom of this curvature, ignore the rising edges as they were simply the result of that surface tension.

Now, if the surface tension is sufficient, and the tube small enough, the fluid will climb up the tube due to 'capillary' action.

So, I would recommend choosing a tube size large enough to avoid too much miniscus curvature, or even worse, capillary action. As such, I'd say that the 2.5mm would be the minimum, 1/4" would be fine.

In a fast-paced competitive marketplace, there's a lot of pressure on publications departments to get brochures, manuals, ...etc. out the door. Things happen, non-tech writers get involved, and some pubs come out goofy, especially if they're trying to translate from an eastern language. You would've enjoyed some of the early Honda tech/parts bulletins we had, kinda like some of the chinese documents we see today. I figure that's the case here. That's one reason why I love this forum. Many fine members here have pointed-out and clarified these things...

I lasted in chemistry class for about a day and a half. The teacher asked the students if they didn't understand what was going on to change classes. I walked out.
Thanks for the answer, TwoMany. I just worry about the little things too much.