Anyone in here have a bike that still has carbs?

[Papa Bear]

I have 2 ..

 

[grampi]

My original point is that ethanol fuel has been available for at least 40 years. It would be reasonable to expect a 1998 model bike to be able to run on 10% ethanol fuel and for that to not cause damage to the fuel system.

The bike RUNS fine on 10% ethanol. My concern is storing the bike with this fuel in the carbs. I've been told by a professional mechanic of 30+ years that leaving a bike stored with ethanol fuel in the carbs will cause seals to deteriorate, and moving parts to gum up. It looks like there are others who support this notion. You apparently have experienced the opposite. I'm not doubting that. I will say I think there are fewer possible downsides to draining, as opposed to leaving the fuel in...

 

[brianl703]

I will say I think there are fewer possible downsides to draining, as opposed to leaving the fuel in...

Does the owner's manual say anything about the issue?

A fuel injector that is "dry" can stick closed. I've had it happen. (The fix was to tap on it with a wrench to free it up). The cause seemed to be the stuff in gasoline that doesn't evaporate and leaves a sticky deposit.

Presumably, the same thing could happen with the needle and seat on a carburetor that is drained but not drained well enough to get every last drop of gasoline out of it, unless perhaps you flush it out with solvent of some kind to get that last bit of gas out of it.

 

[grampi]

Does the owner's manual say anything about the issue?

A fuel injector that is "dry" can stick closed. I've had it happen. (The fix was to tap on it with a wrench to free it up). The cause seemed to be the stuff in gasoline that doesn't evaporate and leaves a sticky deposit.

Presumably, the same thing could happen with the needle and seat on a carburetor that is drained but not drained well enough to get every last drop of gasoline out of it, unless perhaps you flush it out with solvent of some kind to get that last bit of gas out of it.

The owner's manual (this one is from 1997) was written before ethanol was as widely used as it is today. As long as the fuel level is lower than the top of the float bowl (once the engine is run until it quits), it will be below the needle seat...

 

[brianl703]

The owner's manual (this one is from 1997) was written before ethanol was as widely used as it is today. As long as the fuel level is lower than the top of the float bowl (once the engine is run until it quits), it will be below the needle seat...

I'd remove the bowl to make sure it's empty, and disconnect and plug the fuel line so any residual fuel that might still be in the tank doesn't fill the bowl back up as it drains off the sides of the tank over time. And maybe spray some WD-40 into the fuel inlet on the carb.

 

[Motu]

All my bikes have carbs, and I can ride all year, we also have no ethanol in our fuel, so everything on this thread non applicable to me. I turn my fuel taps off before I get home, I don't bother to run them out, but there is not much left...clean fuel on a restart.

 

[Smoky14]

I have stored bikes for extended periods by draining carbs, filling with kerosene. after 2+ years drained the kero and had them fire right up. This weas in the era of the XS 1100 which was known to gum up the carbs.
YMMV
Smoky

 

[grampi]

I'd remove the bowl to make sure it's empty, and disconnect and plug the fuel line so any residual fuel that might still be in the tank doesn't fill the bowl back up as it drains off the sides of the tank over time. And maybe spray some WD-40 into the fuel inlet on the carb.

Unfortunately, the bowls and fuel lines on my bike aren't accessible without doing a lot of disassembly, so I'll just run them dry...

 

[zray1]

My problem with draining the bowls is that the float needle seal will dry out and the floats could stick open as well as possible oxidizing of the aluminum and brass if moisture gets into the carbs. I feel storing with good fuel (E0 if possible) that's stabilized is my best option.

I have never seen this happen. Theoretically possible, yes. But I’m practice must be very rare for me not to have seen st least one case in 50+ years of professional experience.


Conversely, have had to clean out a few hundred carbs over several decades when the gas, pure or a blend, was left to sit too long.

Sta-bil does have its place, but is no substitute for draining the system .

Z

 

[zray1]

That must have been a lot of gas that dried up in those carbs. What did the bottom of the bowls look like?

The bottom of the 2 impacted float bowls were like hard molasses, same looking as the floats and jet area in the photos.

Z

 

[ZeeOSix]

If my '82 carburetor bike is to sit more than a few days I shut off the gas and run it until it quits and then open the drain on the bottom of the carb to drain anything left. Never have an issue.

Sits for just a few days? Gas isn't that bad these days. Seems a bit over board to drain the carbs if the bike sits a few days.

 

[ZeeOSix]

The bike RUNS fine on 10% ethanol. My concern is storing the bike with this fuel in the carbs. I've been told by a professional mechanic of 30+ years that leaving a bike stored with ethanol fuel in the carbs will cause seals to deteriorate, and moving parts to gum up. It looks like there are others who support this notion. You apparently have experienced the opposite. I'm not doubting that. I will say I think there are fewer possible downsides to draining, as opposed to leaving the fuel in...

Fuel is in the carbs 100% of the time when it's being used, so if E10 caused "seals to deteriorate" then that would be true regardless if the bike is sitting or running. Sounds like a misconception by the "professional mechanic" to me.

I'd just use a good fuel stabilizer and leave the fuel in the carbs. As mentioned, the fuel today is better and seems way more stable than fuel of the past. I've never drained the carb on my 35 year old Craftsman lawn mower and have been using E10 in it for ~25 years (most of those with no fuel stabilizer), and it fires up every spring with no issues.

 

[Bud_One]

I have a 20 year old Sportster with a carb.
I splash a bit of Marvel Mystery oil in the gas tank with each fill up.
I have a station nearby that has 90 octane ethanol free gas.
But don't go out of my way each time to fill up there .
I've had it since 2020 and have not had any storage problems with it.
It fires up every time it sits for a while.

 

[zray1]

Fuel is in the carbs 100% of the time when it's being used, so if E10 caused "seals to deteriorate" then that would be true regardless if the bike is sitting or running. Sounds like a misconception by the "professional mechanic" to me…..”

This is over simplification of the blended fuel issues on carburetor equipped vehicles. After 50+ years of taking carburetors apart I have learned that the hysteria about using blended fuels is greatly exaggerated, but does have some basis is fact.

The blended fuels are very safe as long as they are used within 2-4 months, depending how old the fuel was when purchased. At some point during the aging process, a blended fuel will separate into its individual components. That’s when it becomes an issue in carb’d vehicles.

Up to that point I have not found that using the blended gas causes any problems. For reasons I don’t fully understand, fuel injected cars with their higher fuel pressure, generally have significantly less problems using the old blended fuels.


As the photos I posted show, any fuel, blended or pure gasoline, will deteriorate and evaporate over time . Leaving a nasty residue that is a bit*h to clean off, and can even damage carburetor parts beyond repair.

I know the Stabil type products have their fans, but I prefer to at least just drain the carb when the vehicle is going to be sitting for over a couple of months. That strategy takes only a minutes or two, and costs nothing.

Z

 

[KrisZ]

I have two, 77 Kawasaki and a 2000 Honda, but there is no need to winterize a motorcycle here in Texas. I ride all year round. When I lived in Canada I drained the carbs from my 95 Ninja. The one winter I didn’t, I started it up periodically.

But troubles with carburetors due to old gas have been present since the beginning of combustion engines. Ethanol may cause these issues a bit sooner then non ethanol gas, but both will cause carb troubles.

Treated gas should be good for winter storage, but if longer storage is needed, draining the carbs is the best way.
Problem with draining carbs that have old school paper gaskets, they dry out and have a tendency to leak once they are filled back up, but will stop once they are saturated. Rubber sealed bowls may do it as well if the seals are old but may not seal again like paper gaskets. If the rubber is fresh though, there should be no problems with leaks.

 

[webfors]

I have a '98 Honda Super Hawk that has carbs, and I've been told to make sure the carbs are dry when in storage, as today's gas with ethanol is supposed to be bad on them. I've always stored my bikes over the winter with Sta-Bil in the fuel systems without problems, but these were all fuel injected bikes. A local mechanic of over 30 years (he claims) told me loves when people leave gas in their bike's carbs because it brings his shop a lot of business rebuilding carbs. How do you store yours?

I store my bikes hot and wet! Including my carb'd DR650.

I've never drained a carb, and all my engines start without issues every season.

HOWEVER.... I always use 91 octane (ethanol free here) and treat gas with a double dose of stabil and MMO. Small engines always run treated gas, motorcycles get the treated gas on the last couple of rides before the tank is topped off, battery tender connected, and bike is parked.

Your mechanic isn't wrong... those that don't follow my regiment will likely be visiting the local small engine shop for "maintenance". Neighbour of mine bought same snowblower, same year, and he's junked his already. Mine runs strong, smooth and starts easy after 13 years. In fact, it's freezing here now... time to pull her out, remove the cover, prime and I bet she starts on first pull 😁

 

[webfors]

Just got back from outside... snowblower started on second pull after being parked since April 😁

 

[grampi]

I store my bikes hot and wet! Including my carb'd DR650.

I've never drained a carb, and all my engines start without issues every season.

HOWEVER.... I always use 91 octane (ethanol free here) and treat gas with a double dose of stabil and MMO. Small engines always run treated gas, motorcycles get the treated gas on the last couple of rides before the tank is topped off, battery tender connected, and bike is parked.

Your mechanic isn't wrong... those that don't follow my regiment will likely be visiting the local small engine shop for "maintenance". Neighbour of mine bought same snowblower, same year, and he's junked his already. Mine runs strong, smooth and starts easy after 13 years. In fact, it's freezing here now... time to pull her out, remove the cover, prime and I bet she starts on first pull 😁

I think your good fortune is due to you using ethanol-free gas. Gas treatment helps...

 

[ZeeOSix]

I think your good fortune is due to you using ethanol-free gas. Gas treatment helps...

I've never drained carbs when using E10 ... did it for 20 years with no fuel stabilizer and have never had a problem. My 35 year old Craftsman lawn mower still fires up fine every spring. Maybe it has to do somewhat with the brand of gasoline used? ... Chevron is what I've used for decades. The carb has never been touched. I've only started using fuel stabilizer for winter storage in my stuff over the last 3-4 years.

 

[brianl703]

Maybe it has to do somewhat with the brand of gasoline used? ... Chevron is what I've used for decades.

I use Sheetz gas (closest gas station to my house). All I know about Sheetz gas is that it comes from the same tank farm that all the other gas stations get their gas from.