Why is one of my floats sticking?

Had all the carbs apart and cleaned last year and then had it set up correctly. I ride my bike every couple of weeks during the winter and keep the tank full. Last couple of times I've started it up I've noticed the #1 cyl staying cold, even after the others have gotten to operating temps. I little tap with the end of a screwdriver on the offending carb body and after 30 seconds or so I can detect the cyl firing and the exhaust starts to heat up. Pretty soon it's running as smoothly as it's supposed to. So it's a sticky float I'm pretty sure. I don't really want to tear it all apart - again, but is it possible that close to freezing temps together with 8 -10 day layovers making the float a bit finicky? I'm even using the center stand when I'm not riding it daily.

 

I doubt temperature would affect the float needle unless there were water in there freezing it (not likely as would thaw out as rest of engine warmed).

More likely IMO that keeping the tank full & not using it an awful lot, the fuel in there has got a bit on the old side & started to gum things up a little again.

Always advisable to drain the tank & float bowls completely if it's not being used regular (PITA I know, but so is cleaning the carbs)

 

I hear what you're saying, but I can't really drain the tank as I do ride year round( we don't get snow here). Same goes for the condition of the fuel. I burn about half a tank a month so it shouldn't get stale. I suppose I could pop the carbs off and open the bowl on the one carb and take a look see, but before I do that I wanted to check to see if what I'm experiencing is more of a cold weather related issue. Thanks for the reply though.

 

Right ok, guess the juice can't really be going off then if you're using a fair amount (well, lot less likely anyhow)

Do you run an inline filter? needle seat gauzes cleaned out? cold weather should not affect the floats or needles at all so I'm afraid it's likely something else is making that one stick. As you say, you could just pull that bowl maybe with the carbs still installed? and see what's going on in there as regards gunk.

Fingers crossed it's just a freak bit of muck that got missed

 

Make sure the set screw for that enrichment plunger isn't loose or missing. That will keep it from rising with the rest and cause the same thing...

 

Would that be affected by tapping the float bowl though? Pretty sure if that cures it the float is sticking as the o/p suggested. It's something to check though, not impossible that it could happen

 

Could just be a coincidental timing thing. Same thing happened on my bike. Thought it was the float but it was just taking that cylinder longer to warm up. What tells me when it's and float is when there's a noticeable change in the engine sound when I tap the bowl.

 

Could be right, but I'm reading the o/p as meaning that it's still missing once the other 3 are up to temp, and if that is in fact the case, then number 1 pot is going to be warmed enough by the friction & the other cylinder's heat soak to allow it to run without enrichment long before he's tapped the carb :?

 

Definitely sounds like a sticky float, the reason why only one is sticking, that I don't know. When you put the float needles back in place after rebuilding an/or cleaning, sOme say that it is important to put all of them the same way, referring to the very small open wire loop at the end of the needle. I don't know if it really matters.
Personnally, I would say that your #1 carb flaot seat it a bit rough or sticky for some reason.

 

floats can stick open and closed, does the exhaust smell like raw gas?
that would be a stuck open, and if you pull that plug while it's missing the plug should be wet. closed should smell normal and the plug will be dry.
put some seafoam or marvel mystery oil in the gas and see if it clears up

 

When I pulled the plug, it was dry, so it's sticking closed. When I fire it up, the exhaust starts to get a bit warm, so it's firing initially, but I guess once the gas gets low in the bowl it stops firing. I'm not normally inclined to believe much hype about gas additives - except for mythlhydrate, but I suppose I can give it a try. I was quite surprised to find out that just a couple of light taps with the fat end of the screwdriver was enough to free it.
Before I pull it apart I think I'll try leaving it parked on the side stand - see if that bit of angle solves the problem, although I think I'm 'reaching' a bit here for some divine intervention!

 

sounds like the tip of the needle is just a bit sticky, either through age or dirt. Shouldn't be too expensive to get new float needle kit for peace of mind & just tap that carb *just before* starting for now until you get time to do it

 

After a sleepless night worrying about what's causing this - no sense putting it off until the good weather arrives. Time to tear into it and get it clean again.

 

It wouldn't hurt to add some Seafoam in your fuel tank and have it run for 5-10 minutes to give it a chance to clean your sticky float. I'd put half a can in a full tank, give it a shake and then start the engine.

Other way would be to pull the bowl off, fill it up with pure Seafoam, and pull it back on then let it sit for a few days, then drain the bowl, open the petcock to PRIME and let the bowl fill with gasoline, then give the engine a try.

 

Not to get on your case or anything quebecois, but if he's pulling the float bowl to put seafoam in it why not just pull the float pin & clean the needle and seat by hand?

Of course this assumes Hitachi carbs, if they're Mikuni then OK I know why not :? Nasty Mikunis!!! :?

 

Well, removing the float pin could be tricky even when you have the carb rack in hands, I prefer not to imagine what it could be with the carb rack still on the bike :roll:

 

I'm not a fan of gasoline or oil additives. I see lots of hype about how they help clean your engine, help engines develop more power, help shifting problems. The key word in most write ups is 'helps'. I'm not exactly sure how much it 'helps' except for helping the bottom line of the company that sells the stuff. I've even seen the ads for magnets that 'help' mileage. All hogwash as far as I'm concerned. I could have spent $12 on a can of 'whatever' to see if it fixes the problem, but in the end experience has taught me to save my money and just take it apart and clean it correctly. In this case, I've dropped the bike off to my mechanic who only works on old bikes and have it set up properly. Sure, it's going to cost me a couple of hundred bucks, But then I know it's done right. Been using the same guy on and off for 20 years so I trust him.

 

Yes, on the mikunis I understand it is a pig to do, but on the Hitachi carbs the pins fall out if you so much as look at them 8O

 

It's up to you. Seafoam is not a new product on the market, it has been successfully used numerous times to free sticky floats needles. Even if not recommended for heavily gummed up carbs, it is very effective for problems like yours, and used on a regular basis, will prevent them.

 

I know Seafoam has a large following with great testamonials, same as Marval Mystery Oil, but I haven't seen one scientific study which states what the active ingredients are in the can and if it really does work. Guess I'm just a 'prove it' kinda guy. A $12 'mechanic in a can' is what everyone hopes to find, only having to get it fixed 'right' in the end. I suppose if you believe what the manufacturer states to be true, is true, then fine. Im just more inclined to think they will tell you whatever you want to believe to get you to buy the product. - but who knows for sure eh? I do know that if you put enough STP in your oil to stop your engine from smoking, it will stop your engine from smoking. Unfortunately it will also stop your engine from running! I just Googled oil additives and came across one study that tested and posted their results, but your results may very.

 

If the bike was running well when you shut it off last time, the float bowls should be full. If you've got a valve that is sticking closed, then your bike should run "normal" until the bowl is depleted, and THEN start missing on the cylinder with the sticky valve. Like what you described here:

So, my question to you would be "Are you sure?" Are you sure that it's firing initially? Because if it's not, then I suspect the float level is a red herring.

If I were you, I would investigate the possibility that JohnStonePhoto brought up and consider that all of this may be simple coincidence. Maybe you're just running a little leaner on #1 and it doesn't fire right until it gets warmer than the other three.

Maybe try a little adjustment out on the idle mixture pilot screw on that cylinder?

 

SeaFoam is mostly Naptha and mineral spirits.

I picked up all the hoopla about SeaFoam from this forum, so I made the mistake of trying it as a gasoline stabilzer for one winters' layover.

I went back to Sta-Bil.

Here's why SeaFoam won't work to magically "fix" dirty carbs: it can't get in touch with the problem. These are vacuum-operated carbs; if the air isn't flowing, then the SeaFoam-laden gas won't even come in contact with the problem area. It can't magically just go UP, and if what's supposed to be pulling it up is clogged--- it won't do one lick of good.

As a fuel stabilizer, all it did was make my bikes run crappy in the spring; which Sta-Bil never does.

Properly clean carbs simply cannot be achieved by dumping crap in your gas tank.

 

I've had the lean condition before. A quick flick of the enrichment circuit immediately brought heat to the affected cylinder, but not in this case. The only thing that got it firing was tapping the carb, which to my mind, indicated a no fuel situation. So, dirt or varnish or sticking needle blocking the fuel delivery system seems to be the culprit. Ill be able to update in a few days.

 

BigFitz wrote:

Properly clean carbs simply cannot be achieved by dumping crap in your gas tank.[/quote]

I second that. You're on track now tho.

Gary

 

You could verify any float valve theories by checking the bowl levels using the clear tube method before you even pull the carbs off the bike.

 

Good point that man, +1 8) Think we're 99.8% sure but being 100% never hurts

 

Nice thread derail guys! But also an interesting one. So, has anyone ever had a sticky valve or partially gummed jet and had the problem rectified with seafoam? I don't mean the "I used seafoam and noticed more power" kind of statements. I mean " I had a specific problem and seafoam solved it" or, on the other hand " I had a problem that the can said it could fix, but it did nothing but cost me $12 ( or 6 bob for our UK friends,) I think I already know the results, but I've got an open mind.

 

6 Quid I think, 6 bob would be more favourable though, since that's 6 shillings old money, equivalent to 30p/approx. 60c lol

I know it's not a fuel additive, but I have seen a sticking ring on a diesel engine cured by an oil additive "Wynn's diesel stop smoke". That said, this is a one off experience and the ring was more likely freed off with the advice to work the wynn's through the system which was "drive for at least 50 miles, getting the engine fully warmed up & using the full rev range"...

 

I just started a "Seafom stories" thread to answer your question. I hope you'll find some time to read it, it's a bit long but it is exactly what you asked for!