Freaky float function...

I changed my oil a short while ago, drove the bike twice to work and back a total of maybe fifty miles. Checked oil level after the change and after each ride.
After the second ride I noticed that my oil sight level had no bubble!
This means either gas is getting in my oil OR I mixed male and female quarts when filling up and they are doin' it in my crankcase.

Carbs were rebuilt 3 years ago with Len's Deluxe Rebuild Kit, new metal tipped needles and seats included. Inline fuel filter in place.

Pulled carbs, removed bowls inspected needles and saw a very slight witness mark on the tips of all 4.
Rechecked my wet set starting at 4 working towards 1.
When I got to 1 noticed that the fuel flow seemed a little slow, it began to flow better and when checked the level was above the bowl! Closed drain, emptied my measuring tube and rechecked. Level was spot on. Decided to check it again and again it was above the bowl.

What is going on?

Possibly related question, on at least one of the needle tips it was recognized that the very faint witness mark was not concentric. These new needles do NOT have the spring that hooks over the float tang - do the needles rotate while in position? Does having the tang spring matter?

Sad feelings with bike currently out of commission and also faced with a lot of tasks that have it lower than I like on the priority list.

 

Pull the fuel line off the petcock and see if it is leaking. Gas smell in the oil? Looks like one needle is not sealing which is surprising given you have the solid needles. Hopefully just a little trash in the needle seat.

 

start by checking the petcock, make sure it doesn't leak.
now look at the tang of the leaky float, where the needle contacts it, any marks or scratches that the needle could get hung up on.
you could put a dab of toothpaste on the needle and spin it in the seat a few times to burnish it.
remember the whole rack is vibrating on the bike so it my work fine on the bike
those floats work more like a controlled leak than a on-off valve, the real off valve is the petcock

 

Tank has been off the bike for a week, sitting on the floor with petcock in the On position. No leak.
Will pull the needles and seats and do the toothpaste thing with them off of the carbs.

Hope to do it tomorrow but have a crazy schedule on the horizon...

 

From Len's catalog:

Metal-tipped needles, although not original on Hitachi carbs, were used on many original Mikuni carbs. The metal needle tips are much less prone to tip seizure and thus metal-tipped needles do not need, nor use (or even accept) the needle retaining clip

The purpose of this clip is to prevent the rubber tip of the needle from "seizing" within the float valve seat (due to the rubber swelling), or fuel varnish forming around it (and "gluing" it to the brass seat). Since the clip is attached to the float, as the fuel bowl empties the weight of the float pulling down on the needle will tend to overcome any needle tip seizure and prevent that float valve from remaining closed, even as the float bowl empties of fuel.

I also have the solid metal tip needles and they work flawlessly....much much better than the rubber tipped needles.....

.

 

there is a section in lens catalog that speaks of float hinge binding against the float post he sells thin washer shims to help prevent this from happening
could be the problem.

 

oil expands when hot how much of a bubble did you have?
stack some coins under the right center stand leg see if the bubble comes back.

 

Good idea about the coin thing as flat in one spot isn't flat two feet away.
I will double check that, however there is a gas smell and I had approx. a 3/16" bubble.

 

I was helping a friend with some carbs the other day and one of the floats was bound up because of a slight bend in the hinge pin.
I'm sure thats not your issue but a bit of extra resistance at that point would be something that would definitely be a bit of a bugger to diagnose if it was slight.

 

The plan is to burnish the needle/seats. I did polish the hinge pins the other day upon initial inspection. Will look closer at the hinges, as well as the side to side play. I did notice witness marks on the tang where it contacts the needle, probably rub a cotton q-tip on them and see if anything hangs on.

Thanks for the tips, hope to get to it this evening...

 

Didn't get to the bike today, probably a week out. Did harvest a boat load of garlic scrapes and fixed the broken window in the Quonset . . . .

@Polock
Just so I understand the toothpaste burnishing.
A dab of toothpaste on the needle and or seat. Spin needle gently with fingers with very little pressure? Moderate pressure? Push that thing until it hurts?

I know I don't want to gall it - so light pressure is correct?

 

Light pressure.