Floats for VM28 Carbs KZ1000

FYI, The plastic floats in my 75 VM28's have held up fine with todays alcohol gas.

Z1Driver wrote: FYI, The plastic floats in my 75 VM28's have held up fine with todays alcohol gas.

Mine have held up on other bikes I own, I've not had problems on my KZ650 for example.. The floats were playing up for the previous owner on this KZ1000 and when I bought it, I imagined some minor adjustments would have it working like my other bikes do, but that didn't work out for me, I've adjusted the levels at least 4 times, but they don't hold the setting. Either someone "damaged" these floats at some point with some sort of solvent cleaning the carbs or used a fuel additive/cleaner that damaged the surface of the floats so they are porous and absorb fuel - I can't explain why there's a problem, only that there is. The amount the tabs that contact the needle are bent up shows they are not close to floating like they should. I ordered new brass ones because of the better price over the composite ones, we'll see if I made the right choice or should have spent more on composite ones. One way or another I'm hoping this will be the last time I have to remove the carbs for a few years. Based on the experience of others, I will not shy away from buying composites in the future should I need them for other bikes and can get them at the right price. It seems my fears that ethanol fuel could be an issue with composite floats, are not founded, based on the experience of others. The two issues I've had to date with composite floats breaking down must have been caused by something else.

SWest wrote: Have you put them in water to see if the float the same?
Steve

I tried floating them in fuel to see how they floated, but with out a control in the form of a new float I only verified they floated, which obviously they do as the carbs would never work, but the buoyancy is obviously down somewhere. They do seem to look "damp" after being in fuel like it's been absorbed into the surface, rather like a waterproof jacket that's lost it's water proofing.

The tangs can't be on a steep angle or they will cock the needle in the seat causing leak. The tang is for fine adjustments.
Steve

SWest wrote: The tangs can't be on a steep angle or they will cock the needle in the seat causing leak. The tang is for fine adjustments.
Steve

Another reason to get new ones

When I was wrenching I came across all kinds of carb issues. Most of the time it was the PO that made the mistake and the new owner would come to me telling what the PO said it needed. Most of the time it was valves that hadn't been touched, floats that were bent, etc. Unless the parts were broken or missing, 90% of the time I could clean and adjust what was in front of me. I'd bend the tang straight, bend the arms so they plained in with the rest and close to the desired level. With that I would adjust the tangs slightly and all was good. I charged $40 per carb to do this without having to separate them. If that were needed it would cost a lot more of course. I'd call the owner and when he arrived I hit the starter, the bike would spring to life. I loved the grins on their faces. They had to get their short lecture on basic things, but the best part was they wouldn't come back unless it was a tire or something.
Steve

SWest wrote: When I was wrenching I came across all kinds of carb issues. Most of the time it was the PO that made the mistake and the new owner would come to me telling what the PO said it needed. Most of the time it was valves that hadn't been touched, floats that were bent, etc. Unless the parts were broken or missing, 90% of the time I could clean and adjust what was in front of me. I'd bend the tang straight, bend the arms so they plained in with the rest and close to the desired level. With that I would adjust the tangs slightly and all was good. I charged $40 per carb to do this without having to separate them. If that were needed it would cost a lot more of course. I'd call the owner and when he arrived I hit the starter, the bike would spring to life. I loved the grins on their faces. They had to get their short lecture on basic things, but the best part was they wouldn't come back unless it was a tire or something.
Steve

That's generally been my experience until this bike, I did all sorts of work on it and assumed the carbs would be a doddle to work get sorted, but they have been "little buggers". It starts and runs really well for now, but I don't trust the existing floats or current setup. to hold up in use/or lack of it, for too long. It's only a matter of time until the pool of fuel strikes again

My only similar experience was a Yamaha XT200 I had, I took the carb on and off a fifty times but never could get it to not randomly start spewing fuel from the overflow. A new and expensive NOS float cured that one, I think the float lacked so much buoyancy that every time the engine was stopped with the fuel turned off it didn't have the "energy" to do it's job due to some friction somehow creeping in while sitting. That float eventually started to fall apart, one corner turned to dust.

Just a thought but I wonder if ...after thorough cleaning and drying, if a person couldn't shoot the floats with "real" fuel proof clear, found at good hobby shops, and just seal them up.
Readjusting the float arms for the minor change in weight after clear tube, level testing.

May not be your problem but here is what I found on my VM 28's. It seems some guy or several guys got into the carb and found the float pins moved side to side very easily. So the u would take their dikes and scar the pin to hold it in place. I think this led to floct leg breakage when they got too happy with the dikes. They must not have realized the bowl was designed to hold the float pins in place and did not need the additional help.

I have a "B" carburetor that I discovered had a broke float leg. Great repair because it went unnoticed for a long time. The B carb would relief it's self on the garage floor, on the road and in parking lots if the gas was left on. I ordered a new float needle and seat. Installed and did the clear tube test to set the fuel level, If I waited a few minutes the fuel in the tube would go up and pee out of the over flow.

I discovered the broken float leg had been pinned and glued. When the glue gave way, it allowed the float to pull the float leg up the pin that was installed....Somebody did a really nice job of getting this pin centered on the float leg cause it fit like a glove. My solution was getting a set of carbs off of evilbay. I lucked out and got a good set. No body had scared up the float pins and the float legs are intact. Anyways this is the reason one of my carbs would not hold the fuel level. I too thought the float was bad and even replaced it. I was pretty livid when it pissed again after a clear tube test and fuel level was perfect....for a couple of minutes.

MissionKZ, the only problem I could see with your idea of using model fuel proof paint is the possibility of the solvents in the paint dissolving the float.

Z1Driver wrote:
I have a "B" carburetor that I discovered had a broke float leg. Great repair because it went unnoticed for a long time. The B carb would relief it's self on the garage floor, on the road and in parking lots if the gas was left on. I ordered a new float needle and seat. Installed and did the clear tube test to set the fuel level, If I waited a few minutes the fuel in the tube would go up and pee out of the over flow.

I discovered the broken float leg had been pinned and glued. When the glue gave way, it allowed the float to pull the float leg up the pin that was installed....Somebody did a really nice job of getting this pin centered on the float leg cause it fit like a glove. My solution was getting a set of carbs off of evilbay. I lucked out and got a good set. No body had scared up the float pins and the float legs are intact. Anyways this is the reason one of my carbs would not hold the fuel level. I too thought the float was bad and even replaced it. I was pretty livid when it pissed again after a clear tube test and fuel level was perfect....for a couple of minutes.
.

Now you mention it, I had the same issue on a Yamaha XJ650 where a leg had been broken and glued in place, but then came adrift. I wondered at the time how you would manage to break that particular part.

I considered what you might use to reseal a float in terms of a lacquer or paint, I'm sure there's something out there, but by the time you've found something that won't further damage the float or weigh it down, just getting new floats seems a lot easier. The stuff they use to line the tanks in a form that could be applied in a very thin coat should work as the inside of a fuel tank and that of a float bowl both involve being submerged in fuel indefinitely. It seems they had a layer of something on them from new, I wonder what that was.