Author Topic: viton tipped float needle? and plug cap resistance.  (Read 3330 times)

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mutt

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viton tipped float needle? and plug cap resistance.
« on: February 13, 2009, 06:06:52 PM »
Further exporation, with guiding light from this very list! reveals the tiniest crack in one float bowl stand tube, explaining the dribble from one carb. But I think viton tipped float needles are the long term way to go. Does anyone have a source? Ive scoured the parts suppliers listed here under carbs, and tried google...
The centrifugal advance was gmned up, but it now free and a good for on te shaft, & I was able to easily "unscrew"- with the aide of PB Blaster, a great penetrant, 2 of the 4 coil wires. Te others will come out tommorrow, & new wire fitted.
I can either run Packard 440 wire core, or? The plug caps showed 25K ohms, I assume they are shot. I thought just rubber boots, or is there some reason for these resistor type plug boots?
The coils themselves are in spec on the bench, anyway. A little under 5 ohms.
Thank you for any/all input.....

mutt

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Re: viton tipped float needle? and plug cap resistance.
« Reply #1 on: February 13, 2009, 06:07:54 PM »
"A good FIT on the shaft, I mean to type.......

Offline TwoTired

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Re: viton tipped float needle? and plug cap resistance.
« Reply #2 on: February 13, 2009, 06:31:49 PM »
Quote
The centrifugal advance was gmned up, but it now free and a good for on te shaft, & I was able to easily "unscrew"- with the aide of PB Blaster, a great penetrant, 2 of the 4 coil wires.
WTF does this mean?  You might want to re-parse the sentence.

You used PB blaster on the ignition wires?  Is PB blaster a safe chemical to use on plastics?

If you are going to use resistance wire, then you don't need plug cap resistors.
If you are going to use metal core wire, you should have 5k or 10K resistors in the plug caps...and NOT use resistor spark plugs.

You "unscrewed" the wires from the stock coils?

 ???
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Spanner 1

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Re: viton tipped float needle? and plug cap resistance.
« Reply #3 on: February 13, 2009, 06:34:23 PM »
Two Tired is ' fiesty ' tonight !!
If your sure it's a carb problem; it's ignition,
If your sure it's an ignition problem; it's carbs....

Offline Alan F.

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Re: viton tipped float needle? and plug cap resistance.
« Reply #4 on: February 13, 2009, 07:44:16 PM »
My bikes PO unscrewed one of the wires from the stock coils once, he wondered why #3's downpipe didn't warm up very quickly....

Offline bryanj

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Re: viton tipped float needle? and plug cap resistance.
« Reply #5 on: February 14, 2009, 02:20:41 AM »
But standard wires dont screw into the coil so how the *** did you do it
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

mutt

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Re: viton tipped float needle? and plug cap resistance.
« Reply #6 on: February 14, 2009, 06:06:42 AM »
Re: "unscrewing" plug wires. I drove a test light probe a few times between the wire & the coil socket the wire fits in to. I then gave it a shot of PB BLaster, which is great for, among other things, rejuvenating rubber. (For instance, the O rings in the valve adjuster covers were flat, & not sealing. I dosed them w/ PB & they slowly swelled a bit, making a better seal. Its good for carb spigot rubbers, CV diaphragms, etc. But you gotta get them diapphragms back in before they get too big..... It dosnt harm plastic. PB has great capillary action, & soon lubed all around the interface between the epoxy coil & the molded in plug wire. By twisting the wires on two, they broke easily & cleanly with the coils, & I could withdraw them. The two inners were more stubborn and are soaking, Ill give them a tug this AM.
I figure if the new wire is too tight a fit, Ill chase the holes w/ a slightly larger drillbit....
Only other time Ive come across such a thing it was on an XS650 Yam & them wires simply were NOT coming unglued.
The wires that were on there are dated 1972- they simply wont last that long, the insulation breaks down from the......ionizing radiation.
Thx for the resister cap skinny......

Offline MRieck

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Re: viton tipped float needle? and plug cap resistance.
« Reply #7 on: February 14, 2009, 07:57:38 AM »
Viton float needles would be an improvement IMO. Unfortunately you need access to dimensions from other needles or the actual needles. Maybe the DOHC needles will fit?
Owner of the "Million Dollar CB"

Offline Bodi

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Re: viton tipped float needle? and plug cap resistance.
« Reply #8 on: February 14, 2009, 09:22:29 AM »
I can't find the remains but I disassembled (sledgehammered) a shorted coil to see what was inside. As I recall the cable soldered to the cable secondary coil, rather than screwing onto a threaded post like removable wire type coils... so taking the old wire out is somewhat pointless.
Some Keihin carbs have float needles with some sort of rubbery tip... viton? Who knows? But recent float valve replacements ($$$ ouch!) I bought have had all-metal needles, so it may have been a phase Keihin was going through. I've seen plenty of leaks with the rubber tip ones anyway.

Offline MRieck

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Re: viton tipped float needle? and plug cap resistance.
« Reply #9 on: February 14, 2009, 11:26:06 AM »
 The upside of the rubber tipped needles is virtually no wear on the seat.
Owner of the "Million Dollar CB"

Offline TwoTired

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Re: viton tipped float needle? and plug cap resistance.
« Reply #10 on: February 14, 2009, 11:27:44 AM »
Re: "unscrewing" plug wires. I drove a test light probe a few times between the wire & the coil socket the wire fits in to. I then gave it a shot of PB BLaster, which is great for, among other things, rejuvenating rubber.
This is false, I'm afraid.
I have PB blaster, and read the contents on the can.  The part that makes rubber swell is Dipropylene Glycol Methyl Ether.  This is a solvent, that leeches out whatever solvents are in the plastic or Rubber it is applied to.  Any benefit from this application is short term at best, leading to an addiction to repeated applications.  However, eventually the plasticizers in the rubber/plastic will eventually all leech out and be unresponsive to further applications.

PB Blaster is NOT safe for plastics and rubber unless you intend to discard it afterward.

(For instance, the O rings in the valve adjuster covers were flat, & not sealing. I dosed them w/ PB & they slowly swelled a bit, making a better seal. Its good for carb spigot rubbers, CV diaphragms, etc. But you gotta get them diapphragms back in before they get too big..... It dosnt harm plastic.
Yes, it does.  When you get enough experience with it, you will understand this.

PB has great capillary action, & soon lubed all around the interface between the epoxy coil & the molded in plug wire. By twisting the wires on two, they broke easily & cleanly with the coils, & I could withdraw them. The two inners were more stubborn and are soaking, Ill give them a tug this AM.

As Bodi mentioned, the center conductor of the wire is soldered to the internal windings.  If the wires pulled out, it broke that connection.  Simply stuffing another wire into the coil hole, is NOT going to guarantee a connection to the internal wire.  At best you will have another air gap for the spark to bridge, if the gap is small enough, it might work for a while, however, the spark gap will eventually erode the wire short enough, increasing the gap to the point where there isn't enough potential developed in the coil to jump the larger gap.

I figure if the new wire is too tight a fit, Ill chase the holes w/ a slightly larger drillbit....

That will make accommodations for the wire insulation, but not the wire center conductor connection.
I can't imagine this to be a trouble free repair.  But, if you sell the bike quickly afterwards, perhaps you won't encounter these nagging problems.

Good luck!


Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

mutt

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Re: viton tipped float needle? and plug cap resistance.
« Reply #11 on: February 14, 2009, 12:59:36 PM »
Well, I dunno. By leaving a length of exposed wire -  half inch or so, getting it seated against the metal base I can see in the far end of the hole will give metal to metal contact. I plan to put a dab of black silicone around the wire about 1/4 in from where it exits the coil. That will seal out moisture & keep the wire from pulling out. So I dont think disaster is a foregone conclusion.
Same with the PB Blaster. While Im not all that well versed on bike of Oriental provenance, I got a hundred k on the HD I built outta bits, & another 100k in my previous two bikes, both old Triumphs.
I got 100K on the fork gaiters of the Shovelhead, I once in a while wipe them down w/ PB Blaster, and have used it over the years to rejuvenate some rubber o rings when replacements werent available.
Guess Ill quit lookin for Viton tipped float needls tho....
Nice site.
I see that Dynatek makes ignitions for these. We run those ignitions in our bikes- and pile on the miles. Excellant factory support, work a treat, the only failure in a combined??? 225K miles (The Girl rides) was due to a coil going to zero ohms, which the pickups dont like. 8 years out of warranty & they sold me a replacement- exchange- for $80.
It just wants a good mechanical advance, & is compatable (tech support said) w/ the sohc 5 ohm coils....
Ill let you know how the wire replacement works out. The ones existant were shot, SOMETHING had to be done. I think-know- the bare end of wire seated firmly will provide a solid connection.....


Offline mark

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Re: viton tipped float needle? and plug cap resistance.
« Reply #12 on: February 15, 2009, 12:43:40 AM »
..... I think viton tipped float needles are the long term way to go. Does anyone have a source? .....

flebay

not cheap but neither are oem ones.

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F you mark...... F you.