Float valves

[redglbx]

So I’ve been told a number of times over the years that Sudco is the original supplier/maker of the Honda OE float valves, anybody know if this is true or have I just been fed a line ?

[ericheath]

Never heard that, but would be nice if true.

[skydog]

https://www.randakksblog.com/more-probl ... at-valves/

[redglbx]

I’ve seen that article by Mike and even had a cheap Chinese/Taiwanese valve do something similar as well as had them where the angle on the rubber tip is wrong so that the crimp on the outside edge off the tip actually contacted the seat keeping the rubber tip up off the seat. I had this on my 81 CBX last year and was a big part of why I ended up having the carbs in & out 6-8 times which requires tilting the engine down to remove the carbs, no easy task when you know what’s involved.

Those float valves were bought from a valued CBX supplier who sold them to me as oe Honda's forwell over $100. Not even close to matching the oe valve seats. To say I was a-bit po’d would be an understatement.

My belief is that the float valves were made by someone for Keihin who was a subcontractor to Honda. Keihin was at least partially owned by Honda with Showa also being a subsidiary. I am 100% sure that Honda never built float valves ever ! Maybe Keihin did but I suspect they outsourced it as well, so who makes the float valves ? I don’t know but have been told that Sudco was/is the original supplier but I have been unable to confirm that at all. I personally have had good luck with the K+L piece’s, very quality made.

Do the oe’s wear out ? They are well made but the alcohol in the current fuels tends to be hard on the original non-Viton rubber tips causing them to swell and/or deteriorate. The main thing I’ve found bad on the oe valves that goes bad is the spring pin, either the spring deteriorates and fails or it gets varnished and sticks so I tend to replace them because of that. That’s my story & take on float valves.

[Sidecar Bob]

If the pin gets stuck it is usually varnish. Soaking the needle in methanol (AKA methyl hydrate) overnight usually loosens them (not to mention removing varnish from most carb parts as well as an ultrasonic cleaner can).

I've used the original needles in my '79 carbs exclusively with E10 fuel since I got them in the '90s and the last time I looked the silicone tips on the needles were still like new (the same goes for the ones in my winter machine's carbs too).

BTW: Methanol is one of the 4 basic solvents every shop should have viewtopic.php?p=364142#p364142

[redglbx]

Bob, good inputs, thanks. I’ll add that the oe tips are butyl rubber not silicone, maybe viton but the couple I’ve seen deteriorate says they have to be butyl. I’ve worked with a lot of rubbers over the years and silicone would be much smoother/slicker. My .02 I’ll have to get my Rubber book out to see if silicone is even compatible for this application.

[Sidecar Bob]

Whatever rubber they used originally, I've never seen one go bad.
As I understand from people like Mike Nixon, most of the problems attributed to alcohol in the fuel have other causes. Like I said, I've been using E10 exclusively for decades and it has never caused any problems with rubber parts. I wonder how much of what is blamed on ethanol is actually caused by high levels of carb cleaner or other fuel additives?

[CYBORG]

Whatever rubber they used originally, I've never seen one go bad.
As I understand from people like Mike Nixon, most of the problems attributed to alcohol in the fuel have other causes. Like I said, I've been using E10 exclusively for decades and it has never caused any problems with rubber parts. I wonder how much of what is blamed on ethanol is actually caused by high levels of carb cleaner or other fuel additives?

I agree. I've been using ethanol for years as well.

[Rat]

I use whatever the cheapest gas is ... as long as you use enough of it ... no problem

Gord

[redglbx]

Yepper, I’ve used the e10 ethanol in my 76 pretty much since they started making it for the reason that it keeps the fuel system much cleaner, it really helped with all the initial carb problems, the bike just ran better. The problem with ethanol e10 or now the e15 fuel is that the damage is cumulative over time. So long as the o’ring and seals remain captured they should stay pretty much fine. Have you ever had a manifold o’ring swell to where it won’t go back into the groove once you take it out ?

For me, I had the float valve tip crack when I had the carbs apart many years ago before I became viton rubber knowledgeable, and before my later job made me Much more rubber intelligent. Most all fuel system rubber parts these days are OE Viton to resist damage from our ethanol laced fuel. Any vehicle made since probably 1995 or later just negates any Fuel issues, they just run now with the only negative being a slightly reduced fuel economy since ethanol laced fuel has less btu’s of energy, but the plus side is that it will keep the fuel system cleaner, plus the engine should run cleaner, we all like to breathe.

One of the negatives of the ethanol fuel is it draws moisture due to it being hydroscopic along with the lower btu’s of energy. So it’s not good for something that’s going to sit long term, but I believe that is generally overstated. The positives are that the engine should run cleaner (oxygenated fuel) and a bit cooler plus it Boosts the octane rating. It’s a better alternative to the previously used lead (100 times more than needed to lubricate the valves) and waaay better than the toxic stuff used since lead.

Because of the cooling & octane benefits you should be able to get more performance w/o spark knock, particularly in a blown or turbo’d application. More compression & ignition as well as cam timing should be no problem.

[Sidecar Bob]

I've said it before: Ethanol in motor fuel has been around long enough that early Model T fords were designed to run on either ethanol or gasoline so using a rubber that is susceptible to damage from ethanol in the fuel is inexcusably bad design and any engineer who signed off on using those rubbers should be forced to rebuild all of the affected carbs himself.
But as I also said, I doubt if a significant amount of the damage blamed on alcohol is actually caused by it. Otherwise so many of us wouldn't have used E10 for so many years without problems.

I should qualify that by saying that I bought my 'Wing's '79 carbs in the early '90s and at that time I opened them up, cleaned them out (they were full of motor oil because the bike they came from had flipped upside down during the crash) and put them back together with the original parts. Around a dozen years ago I started having some fuelling problems so I bought a popular aftermarket kit and rebuilt them. When I opened the carbs they looked very clean but most of the old o-rings were so hard that I had to break them with pliers to remove them; That must have been caused by the ethanol because it couldn't have been because they were almost 30 year old rubber parts that had spent a lot of that time immersed in gasoline could it?
Ironically, some of the parts from the kit did deteriorate due to a reaction to something in the fuel. The symptoms led me to chase what I thought was starter motor problems for a couple of years before I realized that swollen & cracked carb to plenum seals were causing the problem. When I informed the producer of the kit to help him prevent this from happening to others he sent me replacement parts and explained that the bad ones came from a supplier he had fired because of quality problems not long after I purchased the kit. As I recall, he said they had changed to a rubber that was sensitive to some chemical the refineries add (he also asked me not to publicize hat he sent me replacement parts so long after my initial purchase so I won't mention his name here).
I still use E10 and the new ones are older now than the bad ones were when the symptoms started (& none of the other parts seem to have been affected) so I don't think the problem was related to the ethanol but I'd bet most people who had similar problems would buy into the myth of alcohol causing rubber parts to deteriorate and blame it.

[redglbx]

Bob, good points, I think the fuel gets blamed for a lot as well but I’ll add at least around here the ethanol e10 stuff really wasn’t commonly Available until after the late 70’s gas crunch. And viton rubber that is alcohol resistant wasn’t really available until the mid to late 90’s to the best of my knowledge.

I will add that I believe that the ethanol killing rubber parts is maybe a bit overstated but I have done lab testing on it and butyl rubber isn’t fond of ethanol/methanol over time, it does dry things out and causes it to swell, crack & fail whereas Viton isn’t really affected. It’s one of the reasons I step up and buy Randakks kits because they are made from Viton (supposedly) , but I will add that I believe that most quality rubber parts are Viton these days due to the known ethanol exposure. But I will add that butyl rubber parts are a lot cheaper than Viton parts and is why not everyone is on board, it’s a cost savings thing. So buyer beware !

Let me also say that ethanol & methanol tend to be very corrosive over time with methanol being more so, adding 10-15% ethanol to gasoline is pretty minimal in that regard as the gas tends to have lubricating properties since it’s oil based. Not perfect but it’s what we’ve got ! And I’ll say that like you I think a lot of the gasohol rumor mongering is really overstated.