Ethanol and carb float problems . . .

[CTellman]

In the Feb ON there is a discussion about ethanol and the effect on the carb floats on airheads. Has anyone experienced their tank floats losing buoyancy? I looked at Bob's catalogue and while they offer a conventional float, they don't specifically mention an ethanol resistant float.
My fuel tank liner paint is flaking off. I have cleaned it out and hopefully it is OK. Do I need to get tank recoated?
Thanks,
Campbell Tellman II
'93 R100RT

 

[jpberens43639]

Floats & Tank

The BING agency makes a float kit for this. I've had one in my 1981 R100RS for over 15 years.

" www.bingcarburetor.com " or Google BING Carbs.

I think you MAY need to at least clean your tank out. I drain & wash mine out every couple of years.

 

[VANZEN]

buoyancy

I had experienced loss of Bing float buoyancy (type 94 CD carbs)–
not sure that the cause was ethanol,
(I was in Colorado where the gas contained a higher ethanol %)
or old age (the floats were @ 13 years old).

And bought the Bing "air-craft style" float kit as used by jpberens43639.
Bing advertised, among other "benefits", that the floats are alcohol resistant,
which, to my years of use, is substantiated.

I am happy with the kit, have had ZERO problems with it, however,
as to the original Bing advertising claims of "improved mileage and performance" –
dubious at best.

 

[88bmwjeff]

Two alcohol resistent float options from Bing

Bing now sells two versions of the alcohol resistant floats. The independent float kit, which also comes with new bowls, has been around for 15+ years based on the previous posts. This independent float kit has had mixed comments over the years. More recently, Bing came out with a hinged, non-independent float, which is a direct replacement for the OEM white ones. I have yet to come across anyone who has purchased the hinged version. If anyone has, please post and let us know.

edit: I would clean and drain your tank annually. When there's too much paint on the petcock filters, then you know it's time to re-coat the tank. That's my $0.02

 

[CTellman]

Fuel Tank Recoat . . . .

Is a recoat required? Who does it? How much $?
Thanks,
Campbell Tellman II
'93 R100RT

 

[Bill Burke]

Is a recoat required? Who does it? How much $?
Thanks,
Campbell Tellman II
'93 R100RT

The answers: Yes. You. About $50. The whole process, if done right, takes a good week or so. A real PITA, but worth it. I recommend POR-15.

 

[PGlaves]

My comments in Benchwrenching in the February ON were directed specifically at:

1. OEM white foam floats. The ethanol dissolves the laquer and the foam absorbs gas. Floats get heavy, and upset the fuel level at the least, and sink to the bottom of the bowl and drip fuel all over at the worst.

2. The black plastic split float system that comes with an unvented/non-overflow bowl - that meter fuel less well and can cause other problems.

I have no experience with the new plastic hinged floats, but if they a) replace the foam floats and work the same; and b) have a vented bowl with overflow tube - then they should work fine.

I did get one email inquiring if I also meant the vintage floats on /2 bikes, etc. They are soldered brass. Ethanol can cause corrosion of the brass but it would take an awful long time. The solder might be more susceptible to corrosion than the brass.

 

[20774]

I did get one email inquiring if I also meant the vintage floats on /2 bikes, etc. They are soldered brass. Ethanol can cause corrosion of the brass but it would take an awful long time. The solder might be more susceptible to corrosion than the brass.

They tend to get cracks from a process called work hardening. They'll crack just sitting on the shelf. Once cracked, gas gets inside and they sink. I understand that Vech offers plastic floats for /2s now that eliminate this problem. Plastic, not foam as I understand it.

 

[VANZEN]

good idea !

...
edit: I would clean and drain your tank annually. When there's too much paint on the petcock filters, then you know it's time to re-coat the tank. That's my $0.02

won't help saturated floats, but...
good idea.

that paint (tank liner) can and will chunk off into bits
rattle around inside the tank
knock the screen filters off the petcocks
and make their way into the carbs
causing pure mayhem ...

in addition to coating and blocking those screens,
possibly interrupting fuel delivery.





don't ask.

 

[widebmw]

My comments in Benchwrenching in the February ON were directed specifically at:

2. The black plastic split float system that comes with an unvented/non-overflow bowl - that meter fuel less well and can cause other problems.

I had the Bing dual float kit on my R80 for 50,000 miles than I moved it to my
R100R for another 50,000 miles.

Then I put 40mm bings on my R100R and a new dual float kit on that bike.
I have 255,000 on that bike and I have been very happy with that kit.

What is the metering problem ?
What other problems ?

I have heard others say that they have heard of problems but I have not had any.

 

[47512]

Paul, I have had the independent floats and bowls on a R75/6 for about 15 years with no issues, but I have heard of others that have had running probblems. Mikuni has used the independent float system for dirt bike applacations for years.

I have several old British bikes with Amal carbs, Amal floats are holow, the new fuels make them crack and leak. Another issue is with fiber glass fuel tanks, it seems that the alcohol in the fuel slowly desolves the resin and it ends up a sticky mess on the slides and intake valves.

Ducati has had probblems with the U.S. fuels atacking the plastics in their fuel tanks, making them expand, leak, etc. I have seen the effects the alcohol has on the viberation damper for the fuel pumps on the older K series BMW's as you describe in your artical. This also happens to some of the older German cars with the fuel pump in the tank.

Ken G.

 

[88bmwjeff]

won't help saturated floats, but...
good idea.

I agree, but CTellman also indicated that the paint liner in his tank is flaking off, and my comments about cleaning and re-coating the tank was in reference to that.

 

[6659]

"Another issue is with fiber glass fuel tanks, it seems that the alcohol in the fuel slowly desolves the resin and it ends up a sticky mess on the slides and intake valves. "

I have an MZ Skorpion that has a plastic or fiberglass tank. Can't be sure other than it not being metal. I noticed that the sides of the tank has waves in it recently. I though it might have something to do with the "Stabil" I put in it but when I contacted the manufacturer, he said it must be due to the alcohol. What, as consumers, are we supposed to do as the government sets out to destroy all the old vehicles on the road?

 

[tntimbo]

I would like to know how the Delorto carbs on the R90S hold up with this fuel.

Anybody got an answer?
T

 

[PGlaves]

I had the Bing dual float kit on my R80 for 50,000 miles than I moved it to my
R100R for another 50,000 miles.

Then I put 40mm bings on my R100R and a new dual float kit on that bike.
I have 255,000 on that bike and I have been very happy with that kit.

What is the metering problem ?
What other problems ?

I have heard others say that they have heard of problems but I have not had any.

Well, first off, don't ever leave a petcock turned on by accident. If the needle seeps the bowl fills up, and the fuel then flows into a cylinder. Then - if you are lucky - when you start the engine the damage is to the bottom end from the gasoline diluted oil. If you are slightly less lucky one cylinder will hydrostatic lock from the gasoline in the cylinder. If perchance the other cylinder fires just once you will have a bent rod or two to contend with. If that cylinder doesn't fire you will probably get by with just a broken starter nose casting.

Beyond that, your mixture is likely to cycle between too rich and too lean from time to time - especially in the twisties - because despite the claims, the fuel metering is less precise, not more precise. Too rich just robs you of performance; too lean can damage valves and even pistons.

But other than that they are just fine. You like them and it's your bike so feel free to use them. I wouldn't, but it's not my bike.

 

[Manfred]

My brother (a long time BMW owner/rider) warned me about this float problem when I bought my boxer in December. He thinks my carburetors have "good floats". I guess I'll drop the bowl on a carb this weekend and see what's there.

 

[tntimbo]

Paul G: Do you know of any ethenol nrelated problems with the Delorto carbs?

 

[jammess]

Does anyone know of a chemical that can be used to coat or re-coat the oem floats that can stand up to gas/alcohol? What would varathane do?

 

[PGlaves]

Paul G: Do you know of any ethenol nrelated problems with the Delorto carbs?

I don't - but I have little experience with the Delorto carbs in recent times.

This is probably a good question to post over on the Airhead Club list. I'm pretty sure Tom Cutter is likely to have an answer, as well as others.

 

[dennisdarrow]

So Paul, what do you recommend doing about the float situation. Obviously you are not in favor of the floats that do not absorb or deteriorate because of the problems you outlined............thanks......Dennis