Bad Goldwing Dad & his carb problems

[centurion94]

10-4, just. Not compressing the pin, just touching.

 

[slabghost]

centurion94 » Wed Oct 23, 2013 7:59 pm[/url]":3sihmvt4]
I'm not exactly the brightest bulb in the Easter basket, but are we all agreed that the gas is coming past the needle valves? And very funny, Mike, I missed it the first time. The only movie title I'm coming up with is "Mission Impossible" (not completely seriously...).

:good: Yep the needles and seats are the primary issue at this time.

Now about that heavy duty valve on the hose. Did I spy some forceps there on your tool board? Wouldn't those be easier? :headscratch:

 

[backlander]

If you still have the oem needle valves and seats, compare the length of the needle valve and how it fits in the seat to your aftermarket ones. There could be a difference which will throw your oem float setting off.

 

[centurion94]

Now about that heavy duty valve on the hose. Did I spy some forceps there on your tool board? Wouldn't those be easier?

Uhh, 'cause I didn't think about them? :whistling:

 

[dan filipi]

Yep, agreed it's the float/needles causing all your problems with flooding.

Like I suggested earlier, check where the float actually shuts off when the bowl is removed.

Like I did in this video:

[video]https://www.youtube.com/watch?v=rDqzFROZoJ4[/video]

 

[centurion94]

And yes, I have all the old stuff in little key-sized kraft envelopes, labelled as to contents. I checked before I came inside - yup, the original valves and seats are there. Would I be ahead of the game to just reinstall those? I've since read about cleaning them and returning even the rubber tips to a serviceable condition... by... boiling? In keeping with the season, maybe throwing in an eye of newt and a couple of toad stools?

Well, maybe not the whole toad stool, maybe just a toad stool sample. Wait, I'm sorry, toadstool is one word. Never mind, my bad...

 

[centurion94]

Dan, thanks for the video. opcorn: How did you keep the gas from leaking through the other three carbs while you were checking that one?

 

[dan filipi]

I left the float bowls on the other 3.

 

[centurion94]

I'm missing something here - if the gas flow is supposed to shut off as the tab touches the spring-loaded pin, what's the purpose of that pin? Just how much pressure has to be behind the needle to effect a seal between the rubber point and it's seat? Wouldn't a lower float height start closing the needle sooner and actually exert more pressure, pushing the needle more firmly against the seat?

I'll measure the old needles against the new ones tomorrow, but the new ones were installed with their respective new seats. I'd assume that if the new needles were a tad short, maybe the new seats would be correspondingly more shallow? Of course, this is an assumption utterly devoid of any foundational knowledge or evidence as to its validity...

Is there any more ice cream?

 

[backlander]

Okay, here comes the bucket of worms. This is how it's suppose to work from what I have read on these CV carbs.

Needle Valve:
The needle valve should be closed as the tang touches the spring loaded pin. That pin is there to absorb the vibrations from the float during operation. If it were not there, along with the spring wire that slips over the tang the needle hangs from, vibrational movement of the float would be constantly moving the needle up and down and fuel could not be held at a stable level in the bowl. :heat: Phew, I'm outa breath.

I'm pretty sure you add to the OEM float setting in 1mm increments to lower the height of the fuel in the bowl and just the opposite to raise the height of the fuel in the bowl.

As far as pressure in the bowl, the bowls are vented to atmosphere and that is 14.7 psi at sea level. Actual fuel pressure from pump to carbs should be between 3 or 4 psi.

 

[centurion94]

Thanks Mike. Actually I was referring to the pressure of the rubber needle tip against it's seat. So that little spring-loaded pin is a little shock absorber; I get it!

 

[centurion94]

This is getting absurd. I've removed both the aftermarket float needle and seat. I've measured every dimension I can think of, I've interchanged needles and seats and re-measured, and I can't find a speck of difference between old and new (keeping in mind that overflows were the cause of this trainwreck to begin with - with the old needles and seats.

"Seems like the telegraph was out, Sam, and the old 6:15 piled into the river right behind the "Cannonball" - guess the bridge was still out... mebbe we oughta' think about fixin' that bridge, 'fore we run outa' trains..."

Never mind, my wife can't understand my ramblings either :shock:

 

[slabghost]

Since they are virtually the same either the floats are too high or the needles and seats don't quite match up. Try setting the floats to the proper level. With the method in the video. Needle closed enough to stop flow then float height.

 

[centurion94]

My little gray cells are starting to itch...

I just sat down on a stool at eye level with the carb bank (upside-down) on the bench. With a beer. On a whim, I put a ruler on each float, measuring from the aluminum to the actual lowest edge of each float. Even with the weight of the float on the spring-loaded pin (which didn't seem to notice), I got approx 15mm on carbs 2 and 3 (#1, the worst offender, is still disassembled), but somehow #4 (which did not appear to have a leak) is marginally higher somehow (16mm? ish?). This begs two questions:

1) what would be the effect of setting float height at 14mm?

2) what would be the effect of setting float height at 18mm?

"Sam, y'all writin' this stuff down? Sam?"

 

[slabghost]

14mm will allow the floats too high and likely cause flooding. 18 mm may be a bit low causing a lean condition. As I understand it the floats should be set at 15mm with the needle seated enough to stop the flow of fuel.

 

[zman]

I used a cardboard postal envelope and calipers measured to 15.5 MM cut a tool for setting floats, just an H shape as wide as the carb body and seat it on both sides and run it over making sure the float height and alignment was correct.

 

[centurion94]

Float height, measured as described, is 15.5mm. #4 apparently had a little stiff to it, maybe 16mm. It'll be adjusted. But until I figure something out, the carbs are not going back on this fall.

 

[Ansimp]

Unless you are really aggressive in your riding style I don't believe that you will experience the lean condition from having the float height too low (15>18 mm). Use your statist test rigg to get a height that seems suitable without the potential for flooding.

 

[joedrum]

you be amazed what a little hand work and touch dose..... working the float needle and seat off the carb will do a lot to seal them from leaking ....its seems ive never had a leaker I conldnt stop leaking ....these carbs are fragile and the parts small ...and the margin of operating is way small ...working the pieces together carefully will get them to seal ...out of carb ..... :builder: :mrgreen:

 

[centurion94]

Ansimp and Joedrum, you guys were reading my mind. Or I was reading yours. During the 4am trip to the bathroom it occurred to me that I probably wouldn't lose anything by lowering the float height to 18mm and then removing the strainer from each float seat and then polishing it a little by dipping a q-tip in some rubbing compound and giving it a few rotations. Carb cleaner and compressed air should take care of any leftover compound.

What I'm still wondering is what I can do with that little pointy rubber tip on the needle - race bikes heat up their tires and my bike shop says to ride sedately for the first hundred miles on new tires to help clean off the casting release agent. Maybe these needle tips are gtg as they are, but what about a shot of carb cleaner or vinegar, followed by Armorall?


"Sam, remember what Dan said? Go put this c-clamp away and hand me that there hemostat...!