How to unstick a stuck carb float??

[silverbub]

been suggested by dealer mech to take screwdriver handle & tap on carbs to jar the float off the stuck position (stuck so that carbs 'bleed' gas out overflow)...ok, so this is a 91 vfr & after taking off the side panels i saw the back two carbs are the ones stuck & won't lift to shut off gas flow to bowls...bike ran perfect & sat for about a month)...too tight a fit in there to go knocking around on the carb bodies...someone suggested using hammer & tap lightly on carbs with handle of screwdriver on bodies...sounds risky!...anyway, over on vfr discussion group that i searched yesterday after registering found one response for someone there asking same question...the responder said to check to see which carbs are leaking by using a TORCH!!! so see into the dark areas...YEAH, RIGHT!:o4: SOOO...i want to ask my fellow st'ers for some reasonably plausible means to jar the floats from their stuck position without damaging carb bodies & without going into a "full carb overhaul(which was done about five years ago...) is there a "vibrator" for carbs?...no wise cracks, please...thanks in advance:03biker:

[bcst1300]

Hey Silver. The long screw driver and a light tap with a hammer is good. place the handle end against the float and tap the tip with a light plastic faced hammer. The "Tourch" is a flashlight in England. Sounds like the carbs need cleaning and a rebuild kit.

[Dorian]

bcst gave good advice there. I had lots of experience with a 1980 CB750K. I put over 150K ulitmately on that bike, had to deal with stuck floats on several occasions.

Screwdriver on the carb, medium tap with a hammer gets the job done. However, its a sign that things are just going to get worse. You may as well learn how to rebuild the carbs now. Carb cleaner can get you by for a while, but if the bike sits long enough for the floats to stick other things are starting to setup.

By the way... anyone want to help me get an '85 750 running that hasn't been started since 1993? It only has 7K miles on it and the owner just dumped it in my lap, saying "I'm tired of lugging it around everytime I move." Besides rebuilding the carbs (the hammer and screwdriver just ain't enough!) I'll be completely resealing (new gaskets and seals) the top end and probably the lower end.

[alan]

bcst gave good advice there. I had lots of experience with a 1980 CB750K. I put over 150K ulitmately on that bike, had to deal with stuck floats on several occasions.

Screwdriver on the carb, medium tap with a hammer gets the job done. However, its a sign that things are just going to get worse. You may as well learn how to rebuild the carbs now. Carb cleaner can get you by for a while, but if the bike sits long enough for the floats to stick other things are starting to setup.

By the way... anyone want to help me get an '85 750 running that hasn't been started since 1993? It only has 7K miles on it and the owner just dumped it in my lap, saying "I'm tired of lugging it around everytime I move." Besides rebuilding the carbs (the hammer and screwdriver just ain't enough!) I'll be completely resealing (new gaskets and seals) the top end and probably the lower end.

I still riding my 1969 CB750, had it out last week. I have had the sticking float many a times over the years. On mine, you can just pop off the spring clip that holds the float bowl and wiggle the float to free it up. I have 33,000 miles on this bike and bought it brand new. I have never had to rebuild the carbs.

[NCrider]

After you break it loose, use Marvel Mystery Oil in the gas. This stuff WORKS!!!

An old motorcycle mechanic turned me on to it. He said it cured 99% of the carb problems he had come through his shop and he was known as the best MC mechanic anywhere around.

[silverbub]

thanks, fellas, for your helpful replies...i guess i will try the hammer(plastic)/screwdriver technique...i was worried about doing too strong of a "KNOCK" on the carb bodies castings...besides...it's hard to tell where the bowel part of carb bodie is on the little buggers...not as obvious to my eyes as it was for automobiles back when...and thanks, andrew, for tip/reminder about marvel mystery juice...i also am believer in it, but had not thought of it as being a good elexir after i get the two floats floating again...seems to me such a common problem would have ment that mechanics would have come up with some "slam-hammer" gadget or an "impact" imparting gadget that would be safer & better than hammer/screwdriver...think about having a spring loaded mechanism that would impart somewhat random shockwaves through carb body sufficient to shake up those floats off their stuck points...or an electrical device that would be shielded, of course, that would send random shock waves on the carb body/internals...:bow1: :03biker:

[Lager]

Carb floats can stick and cause flooding for a few different reasons.
The most common is caused by a bike that has sit for a long time without running and the gasoline has evaporated from the float bowl,leaving behind a tarry substance that sticks the float valve in the down position.Banging on the lower carb body/float bowl,might correct/loosen it up..But the Idle jets will be plugged with the same tarry substance causeing an idle misfire.The only repair there,is remove the tank,, clean, remove the carbs and clean.
Reason #2,, trash in the fuel tank,flowing into the Carb, the trash getting stuck between the Carb float valve and its seat. banging on the Float bowl might dislodge the debris,but rest assured, the debris will be sucked up by either the Idle jet or the main fuel jet causeing more problems.Missfires or lean running on that cylinder.The repair here, is to remove fuel tank,clean out the offending debris,remove carbs and clean.Have we noticed a lasting repair trend here?
Lastly,now here is where we get into the strange stuff that hardly ever happens, but its possible.Believe me, after almost 40 years of working on Bikes, Ive seen it..
Poor repair from the person that last worked on the carbs.
Worn out float valve,this is real rare unless you have a really old bike.
Fuel evaporation,remember the gunk it leaves behind,but not enough to plug the fuel jets, a Cleaner might help there, Mystery Oil actually does work.
A float set,there are two floats per carb ,that has one float working correctly,the other is fuel logged, causeing a binding against the float valve..Forget that one,, I only seen it once and lost a lot of money on that repair. Ahhh,, thats about it? Unless you have an Old Norton with the carb Tickelers that served as a choke,but I dont thats the case here.;)

[silverbub]

thanks to all of you fellas' advice & encouragement...i now have the floats on number 1&3 carbs on 91 vfr doing their intended work again...w/o having to "go-deep" & pulling carbs...i took a long oak dowel that will go into the stove come winter...and grabbed the 2 1/2 pound short handle sledge hammer & spent time tapping progressively harder on the carb bodies(after pulling side panes, of course)...number 1 carb float broke free of being stuck rather soon...heard it "ping" as it rose in the bowl...number 3 carb float took longer & was a multiple days affair...bang on carb body for awhile with & without engine running...(& having gas overflow from bowl)...until i got concerned about engine getting too hot & too much gas on engine...then i would get glum & quit for day...few days later, with renewed optimism...went back to banging on carb body again...even used a steel socket extension to mildly tap a different shock wave into carb body...made a few mild dents on carb, but not functionally a problem...low & behold...#1 float broke free last weekend & i immediately put a pint(16 oz) can of "sea foam" cleaner/conditioner into tank & ran bike for a thirty mile trip...checking frequently for any more overflow of gas...none!...so, again, thanks to all of you i hung in there & did not have to go to the $mech route...hope my description can help someone else with similar problem...give the hammer/dowel, etc a try for a few days before giving up!...:bow1: