Carbs - bowl draining or additive?

[Beer van Huet]

I ride my Valkyrie for 25 years now and have a habit of running the engine monthly in wintertime until the fan comes on.
The last few years however, my wife and I are using our camper and stay in the sun away from home for 3 months or so.
Up until now I have used fuel additives and the engine always runs fine after I get back.
When I did some maintenance, I noticed Honda recommends emptying the carb bowls in the manual when the bike is not used for a month or longer.
Right now, I am in doubt if I should do that instead of using additives.
I guess both methods have their pros and cons.
Additives may not always work properly with clogging the jets as a result.
Draining the carburators dries the float valve or pin and seals, rubbers or other interior parts.
So I would like to ask your opinion (from experience) about draining the carbs and leave the bike just like that.
Besides synchronizing, changing a throttle cable and tightening the nuts once in a while, I never touch the carbs and hate having to take them off if I can prevent it.
TIA
 

[98valk]

honda is wrong.  the bowls cannot be completely drained unless they are removed. Always use a fuel storage stabilizer.
here in the states I use Sta-bil, have never had a problem, even after sitting for 3 months in the winter.

https://www.goldeagle.com/brands/sta-bil/

[-mike-]

Hi Beer!

First of all, letting it run once a month in Winter is a bad idea.
Condensed water in a somewhat still cold exhaust will detoriate the inner construction quite fast.
I have a lot of  these issues recently reported and in my shop over here in VRCC Germany.
New exhausts are getting scarce and expensive.

Always make sure the exhausts are really hot and dry before you let the Valkyrie sit for a longer period of time.

If you trust your petcock and your float needles, then it is a good idea to keep the fuel system always full.
I personally use just ethanol free gas.
Working in the gasoline industry I can tell you the cleanest brand over here is ARAL Ultimate 102 (about 0.05% Ethanol) followed by Shell VPower Racing with guaranteed less than 0.5% Ethanol in it (most of the time much less).
Keeps the water out of the system and tank, too, if you keep the carb and tank full to the neck with the stuff and you wouldn't even need stabilizer additives.
For ones mind sake I found the Briggs&Stratton Fuel Fit the most effective long term additive you can get over here in Germany.
Marine Sta-Bil is a legit recommendation, but isn't easily available here. You may be lucky in the Netherlands, though.

If you want to play it safe, not risking a hydro lock, for storage just top up the tank up to the brim, slosh some long term fuel stabilizing additive into it, (if absolutely anal, add an ounce of 2 stroke oil), then run the carbs empty, to get the stuff into them, too. Park it  and open the drain screws. Let them open to vent.
Good o rings in a good maintained Valkyrie will survive that easily.

Best of luck!
-mike-

[mbramley]

 I don't have all the science that many on here have but... I live where my bike is parked in a semi heated garage for 3-5 months a year. I have owned my Valkyrie for 10 years and each winter I use Marine sta-bil additive. The marine sta-bil uses and additive that outgases and treats exposed internals of the tank and carbs. I used to use it on my carberated boat and read it was good for any gasoline engine (lawnmmower, bike etc.) I use it on anything I won't be using for awhile.

[Joe333x]

I have always been a stabil guy, put it in and then put my bikes away and plugged in and don’t touch them til spring. Until I got a Valkyrie and after a full carb rebuild and running perfectly all summer long then when I put it away with stabil she didn’t want to run right in the spring. I ran some B12 through it and it cleared right up. This year I been starting her up once a month and letting her run until the radiator kicks on.

[da prez]

    M A R I N E   S T A B I L   only.

                                                      da prez

[HayHauler]

    M A R I N E   S T A B I L   only.

                                                      da prez

+1.

Hay 
Jimmyt

[h13man]

Had same issues with Stabil which was always sluggish hard starting especially on the VT1100C in the spring and turns brown if you don't use it on a regular basis. I guess buy it quantities for each season of use? 89-90 octane for layup period always but 87 thru the season.

Having a Pingel manual petcock, I upright the bike and fill my bowls/tender the battery at least twice a winter layup. Basically it keeps all o'rings in the system "wet" thus no leaks/smell so far and all original 99' parts that I know of.

I use Supertech fuel conditioner for the past 6 yrs. and the Valk always start within two pushes of the start button. Last year one push, full choke. On a note, the Honda OEM manual suggest 8,000 mi. plug change and I have 14,000 on the iriduims so far w/o issue. I've had failures 2x on different cylinders right at 10,000 mi.

Only time I use the enrichner/choke if the bike sits more than 2 wks. The ST conditioner has slight fuel oil smell similar to the old Gumout carb cleaner  I use iriduim plugs which greatly improved the VT1100 cold starting and obviously the Valk also.

[Joe333x]

Had same issues with Stabil which was always sluggish hard starting especially on the VT1100C in the spring and turns brown if you don't use it on a regular basis. I guess buy it quantities for each season of use? 89-90 octane for layup period always but 87 thru the season.

Having a Pingel manual petcock, I upright the bike and fill my bowls/tender the battery at least twice a winter layup. Basically it keeps all o'rings in the system "wet" thus no leaks/smell so far and all original 99' parts that I know of.

I use Supertech fuel conditioner for the past 6 yrs. and the Valk always start within two pushes of the start button. Last year one push, full choke. On a note, the Honda OEM manual suggest 8,000 mi. plug change and I have 14,000 on the iriduims so far w/o issue. I've had failures 2x on different cylinders right at 10,000 mi.

Only time I use the enrichner/choke if the bike sits more than 2 wks. The ST conditioner has slight fuel oil smell similar to the old Gumout carb cleaner  I use iriduim plugs which greatly improved the VT1100 cold starting and obviously the Valk also.

FYI just from my own research, iridium plugs will prolong your service interval but copper plugs actually provide a stronger spark and are better for performance.

[h13man]

Tell that to my VT1100. 

Just my shared experience that worked/works for me thus kinda opposite of the info you posted and yes $50 a set of 6 is a bit much but if one changes the resistor plugs every OEM 8,000 change 2x/16000 mi., $36 this could be an acceptation to best starting conditions but so far NGK iridiums are the better so far in my use.

[Joe333x]

Tell that to my VT1100. 

Just my shared experience that worked/works for me thus kinda opposite of the info you posted and yes $50 a set of 6 is a bit much but if one changes the resistor plugs every OEM 8,000 change 2x/16000 mi., $36 this could be an acceptation to best starting conditions but so far NGK iridiums are the better so far in my use.

Yeah I’m just going off of research, I’ve never put iridium’s in anything except cars or trucks that called for them but the service interval on those is like 60,000 miles. I had looked into putting them in my bikes but came back with information like this from google.

Copper Spark Plugs
Pros: Highly conductive for strong spark, excellent heat dissipation, cheaper.
Cons: Short lifespan (20k–30k miles), soft metal wears quickly.
Best For: Older, carbureted, or vintage vehicles.
Iridium Spark Plugs
Pros: Extremely durable (60k–100k+ miles), finer electrodes mean better ignition efficiency and fuel economy, less likely to foul.
Cons: High cost.
Best For: Modern, high-performance, or turbo/supercharged engines.

[John Schmidt]

   M A R I N E   S T A B I L   only.

                                                      da prez

Same here, plus fill the tank with liquor free gas. I use the Shell hi-test, has no ethanol and fill the tank on top of the Stabil so it mixes good. By the time I get to the storage location, the bike is well warmed up and the fuel mixture is now well mixed within the carb bank. Usually just a couple hits of the start button does it in the Spring. Only had to do this the last 6 winters...I moved from Florida to wisconsin.

Here's a little tip I got from a gent out west, we don't hear from him much anymore but the tip is a good one. You use it to help clean the possible debris from the bowls and is effective if you still have all the bowl drain tubes attached. Locate the carb drain tube under the bike, attach your little brake bleeder pump to it, pump up a bit of vacuum and open just ONE bowl drain. The vacuum action causes a bit of turmoil in the bowl, causing possible debris to break loose. If there's any debris it will show in the catch canister of the vacuum pump. Be sure to close that bowl drain and repeat with the next carb. You can check your results by closing that same drain and repeating the cycle before moving to the next carb.

[HayHauler]

   M A R I N E   S T A B I L   only.

                                                      da prez

Same here, plus fill the tank with liquor free gas. I use the Shell hi-test, has no ethanol and fill the tank on top of the Stabil so it mixes good. By the time I get to the storage location, the bike is well warmed up and the fuel mixture is now well mixed within the carb bank. Usually just a couple hits of the start button does it in the Spring. Only had to do this the last 6 winters...I moved from Florida to wisconsin.

Here's a little tip I got from a gent out west, we don't hear from him much anymore but the tip is a good one. You use it to help clean the possible debris from the bowls and is effective if you still have all the bowl drain tubes attached. Locate the carb drain tube under the bike, attach your little brake bleeder pump to it, pump up a bit of vacuum and open just ONE bowl drain. The vacuum action causes a bit of turmoil in the bowl, causing possible debris to break loose. If there's any debris it will show in the catch canister of the vacuum pump. Be sure to close that bowl drain and repeat with the next carb. You can check your results by closing that same drain and repeating the cycle before moving to the next carb.

I ditched that drain tubing long ago, but I like the idea of applying vacuum to the port on the bowl drain.  I can easily attach a tube to the drain port and do this procedure one at a time.

Thanks for the idea....  #5 carb seems to have a slight miss at idle and I need to see if there is some debris causing this.

Hay 
Jimmyt

[John97]

The carb drain tubes are something I’ve always appreciated and kept on my Valk. They function as intended and that’s much better than my Magna where opening the bowl drains covered the engine in gas. I tried putting a hose to each carb but one is such a tight fit that the tubing gets kinked and spills gas anyway. The semi-permanent way like the Valk rocks.

I use only Marine Stabil as I was told by an independent shop owner he felt the ref Stabil didn’t last as long as it should or used to. I do not drain the bowls. The last time I did for whatever reason one float got stuck and my overzealous tapping with a screwdriver tapped a hole through the carb body which led to several unsuccessful attempts at repair before I finally fixed the hole without leaking. I’d rather not do that again.

[Joe333x]

The carb drain tubes are something I’ve always appreciated and kept on my Valk. They function as intended and that’s much better than my Magna where opening the bowl drains covered the engine in gas. I tried putting a hose to each carb but one is such a tight fit that the tubing gets kinked and spills gas anyway. The semi-permanent way like the Valk rocks.

I use only Marine Stabil as I was told by an independent shop owner he felt the ref Stabil didn’t last as long as it should or used to. I do not drain the bowls. The last time I did for whatever reason one float got stuck and my overzealous tapping with a screwdriver tapped a hole through the carb body which led to several unsuccessful attempts at repair before I finally fixed the hole without leaking. I’d rather not do that again.

I’ve come to the realization that it’s not really fuel going bad that is typically the problem. Stabil keeps fuel fresh longer meaning it will work, which you don’t really hear about people having an entire tank of gas go bad, it’s typical the ethanol in the the gas sitting in the carbs that creates the issue, the longer the ethanol sits the more of an issue it becomes, it’s why a lot of modern day small engines like snowblowers have a fuel shut off so you can run the carb dry. Now if you use ethanol free that gas can sit in there without causing any problems but when you open these carbs up and you see the crud and green residue left from ethanol it makes you realize that stabil can’t really do much to prevent it. Personally I think the best course of action is to keep fresh gas in the carbs by letting her run once a month. I’ve been a longtime opponent of doing this because of the other things running the bike in cold weather can cause but in all reality some guys will ride these all year long so starting the engine up once a month isn’t going to kill it but leaving it sitting with ethanol in the carbs all winter long definitely will. It’s kinda taking one evil over another. I’ve looked into getting non ethanol fuel around me but the best I can get is Avgas but that has lead in it so I don’t think that’s actually a better option.

[SPOFF]

I've always been in the store-it-wet camp because letting the fuel-rail o-rings dry out is a much bigger problem than clogged pilot jets. I'll let you know. Due to a various problems with 3 other bikes the Valkyrie was never started in 2025. So between that and the longest winter in 500 years, the carbs have been unused almost 20 months. I expect a big carb cleaning job in the Spring. Fortunately the Valk already is disassembled so carb access won't be a problem.