what does this sound like?

[awander]

My '52 FL with stock thru-tank shutoff and Linkert M74B has been running great for the last 6 months.

About 3 weeks ago, I noticed that the bike was getting harder to start. My usual starting routine is:
gas on
choke on full
retard ignition about halfway
3 prime kicks
choke to 1-click on(almost off)
ignition on
open throttle slightly
kick

and it has always started on the first kick.

When the trouble started, I would kick and kick and the bike would not start. Experimentation taught me that if I was in this situation, if I flipped the choke all the way off, and opened the throttle all the way, it would start in 4 or 5 kicks.

Then I found that if I didn't do any of the prime kicks, but just started the bike, with no choke, it would start in 2 or 3 kicks.

I also noticed that I was having a small gas leak problem, around the same time. I would come back to the bike, and the garage would smell like gas-and I would find a small pool of gas on the engine case, behind the timer. I tightened all the fittings as much as I though was prudent, but the leak was still there.

I felt around on the carburetor, and it seemed as if the carb was wet with gas even above the level of the float bowl. This made me start to suspect a combination of my shutoff valve, and either the float valve, or the float itself.

Today I took the carb off, and wit the float and valve still in place, I noticed a few things:
-If I inverted the bowl, and blew through the gas inlet, the valve would sometimes seal the air off completely and sometimes "almost" seal it off.
-the float had a lot of side-to-side play. This appeared to be due to a a large clearance between the float lever and the float lever pin.

Then I took the float out and noticed:
-When I took out the screw for the float lever pin, the screw and the pin were separate. My "Panhead Service Manual 1948-1957 Rigid" shows the float lever pin as one piece with the screw. The screw, though, is definitely built with a bore in the underside to accept the pin.
-the float was big enough that I had to really distort it to get it out of the bowl

So, my questions are:
-is the separate pin and screw for the float lever correct? If not, and disadvantage too using it?
-Should the float be that big? If not, is it swollen from gas absorption? (do I need a new float?). If so, where is the best place to get a replacement?
-What is the best way to make the float lever fit the float lever pin better? There is quite a bit of free play between them. I could make up a brass replacement pin on the lathe, with a larger diameter section in the middle for the float lever.

[FlatHeadSix]

-the float was big enough that I had to really distort it to get it out of the bowl
So, my questions are:
-Should the float be that big? If not, is it swollen from gas absorption? (do I need a new float?). If so, where is the best place to get a replacement?

Andy,
1. Very good description of a very common problem with old floats. The new fuel formulas are attacking the older floats, you are lucky it took this long for it to hit yours.
2. No, the float should not be that big. Again, the bad gas got ya.
3. Yes, but the swelling is not so much from absorption as it is from the composition of the newer fuels, the additives and the older float materials are not compatable.
4. Yes, you need a new float!!!!
5. Cotten's floats are the best available, the Liberty Durable Float. shoot him a PM, he'll hook you up.

After installing one of Cotten's floats all your other problems will disappear, as if by magic, and your bike will return to its old staring routine and life will be good, trust me.

mike

[john HD]

and,

your float lever and pin probably need replacement as well.

john

[Cotten]

Andy!

Pins are easy to find, but quality levers are a real problem these days.
The only decent ones I could find at D-port came attached to a boatanchor float.

I made a die to press the original lever's bore slightly shut, and then ream to a sweet fit.
You really do not want much side slop if you can help it.

Note also that there were possibly four different lengths of pivot nut (the top-hat shaped thing that goes through the float) in 1/32" intervals. And there were two different threads for the screws as well.

If your float was one of my earlier (pre-june of '08) productions, I replace them free of charge,with one of the latest improved material.
You need only to return it to me for verification.
I remove swollen 'Armstrong' floats without breakage by putting the whole bowl under a heatlamp for a minute or so, softening them.

....Cotten

[awander]

Thanks for the replies, Guys!

I sent my order off to Cotten a little while ago.

Cotten:

Thanks for the ideas on fixing the slop between the pivot lever and the pivot pin.

Am I likely to have problems mounting the new float to this pivot pin, because of the differences in the nut and the screw that you mention?

[Cotten]

Andy!

Ideally, there will be a very slight compression of any float by the lever before the screw bottoms it out upon the tophat-shaped pivotnut that inserts within the float.
Hopefully, this compression will hold the float from swinging sideways.

My DURABLEs are quite brittle, so I suggest only ~.020", which can be achieved by either fileing upon the float itself (the closed-cell foam cannot "leak"), or upon the pivot nut.

(The lengths of pivotnuts corresponded roughly to various productions of float materials in the past: When the "Armstrong" float appeared in the '50s, they returned to the long Schebler length of the 'Teens'!)

Finding an 'off-the-shelf' adhesive to lock the float to the lever is difficult with today's digestive fuels.
This was the first year that JBWeld has failed in my local P4gas, so now I am suggesting a contact adhesive from the local hardware store called "Pliobond".
(I use an isocyanate urethane watertower coating from the industrial supplier TNEMEC.)

Before locking the screw, it must be certain that the float does not hang up upon the bowlstem.
The manuals' instructions for offset are critical for all models, but particularly for Flattys whose bowls can rotate:

Often the float will be ~1/8" from the side of the bowl.

OFFSET.jpg (28.37 KiB) Viewed 2605 times

The entire carburetor should be inverted to first listen for the action of the float opening and closing, and then one should suck upon the valve to assure that it is sealing properly.

Some carbs can be pesky.
The portion of the bowlstem most likely to interfere is a ledge at the bottom:

STEMCAST.jpg (52.69 KiB) Viewed 2602 times

This ledge can be safely ground away as shown. By the Pan era, the castings were already relieved in this area. On some occasions, there are even lumps in the sand-casting in other areas much higher upon the bowlstem.

....Cotten

[awander]

Thanks, again, Cotten, for all of that info.

What about float height? Does your Durable float get set to the same height as the stock float?

[Cotten]

Andy!

Absolutely!
One quarter of an inch like the Book.

Although my ultralight floats are smaller than the originals, their volume is calculated to approximate the original buoyancy.

"Square" in the bowl is more critical than a precise level opposite of the lever. Although brass floats' settings proved critical to operate "reasonably" right down to the gnat's patootie, and only then by tedious trial-and-error...., light floats can be measured with a dime-store ruler.
Strangely, I have had folks report back that they have had remarkably good results with my floats set anywhere from 3/8" to 3/16"!
To me, this means that the need for extreme accuracy drops out of the equation if the float floats.

....Cotten

[awander]

Thanks, Cotten.

BTW, I made a die for the pivot lever last night, and successfully swaged it tighter, followed by reaming with a 3/32" reamer. The pivot pin was then tight at one end only(one end of the PIN, confirmed by flipping it around). So I stoned the pin on a fine flat India stone and now it fits great!

I made my die by drilling holes in a piece of 3/8" steel bar, and then bandsawing off about 1/3 of the hole, then deepening the cut slightly with a fine round file. The hole diameter(or, I should say, drill diameter) that ended up working for me was a #12 (0.189"). This gave me a piece that I could use against a vise jaw, to press the pivot lever pivot into the cut. Not the prettiest tool I have made, but it seems to have done the job!

0905111741a.jpg (23.67 KiB) Viewed 2577 times

(the tapered shape is because I used a scrap I had laying around.) You can also see some of the other drill sizes I tried first.

Thanks again for the idea! I was kinda' thinking of just squeezing it with pliers, but I am sure that would have caused more problems than it cured.

[Cotten]

Andy!

Yours looks a lot like mine.

....Cotten

[awander]

Got the Durable Float today in the mail. I must say, it was packaged nicely.

I spent a few hours this afternoon and evening getting the float mounted, and setting the correct level, as well as making sure the float was "square" in the bowl.

My hollow nut was too long, and I had to remove about .030" in order to make it fit the float with a .020" compression. Filing the nut was easy, and I got it to about .015" shorter than the float, so I figured that was good.

Next, I assembled the valve, valve lever, pivot pin and screw, and float, and checked the level-it was way off (about 1/2" below the top of the bowl), and not square, so I pulled it apart, bent the lever, re-assembled, and checked again. I repeated that process about 17 times, an each time the float would be different from where I expected it to be.

Then a light bulb went on-I wondered if the end of the nut, that I had filed, was square to the shank? Of course, it wasn;t, and assembling the float would sometimes rotate the nut, so that it ended up differently every time.

How to get that thing square? Obviously, my hand and eye didn't cut it. I toyed with trying to put the nut in the lathe, inside an split collet, but couldn't;t think of an easy or elegant way to do it. Then I decided to drill a close-fitting hole through a piece of 3/16" aluminum I had laying around. A #19 drill gave me a hole that the nut shaft would just pass through. This let me push the shaft down through the hole, while moving the aluminum plate over a piece of 1000 grit sandpaper, and taking off another .005" got the end nicely square.

i reassembled, took it apart for a few more tweaks, and got the float nicely square in the bowl, and almost exactly 1/4" below the top of the bowl when the valve was closed.

Next, I used some Permatex Aviation Form-a-gasket to cement the float in place to the lever and screw. I could't figure out what else to use; I don;t know how well it will work.

FInally I assembled the entire carb, with a new bowl gasket and crush ring under the bowl nut. I did the "flip over and listen for the float moving" as well as the "suck on the fitting"" test, and passed both. Then I mounted it on the bike, hooked up the gas lines, snugged everything up, turned on the gas, and reached for a beer...but before I could take a sip, I smelled gas, and noticed it was coming out of the joint between the carb body and the bowl. I checked the snugness of all fittings, and they were good. It looks like the float is hanging up somehow and not closing the valve.

By this time I had inhaled enough gas fumes (not to mention that beer) so I decided to call it a night.

I'm going to take the carb off the bike tomorrow, and test it that way-and disassemble it and see where the float might be hanging up. Also thinking of testing just the bowl with float and valve, using parts-washer fluid, with a cork in the hole in the bottom of the bowl.

Any advice on what else to look for?

[john HD]

andy,

sounds like you are getting close. i swear i had mine apart 20 times before i got it right!

keep at it!

john

[awander]

Thinking some more(could be dangerous!), I sort of disregarded Cotten's advice on making sure the float does not hang up on the bowl stem. I was thinking, well, it never did before, but of course the new float is smaller in diameter than my swollen one, and it is set differently on the lever.

So that''s the first thing I checked. Not easy to do, between holding the crab shut, inverting it and sucking on the fuel inlet-but it was definitely hanging up on something-not all the time-but about 1/2 the time.

So I moved the float a bit further toward the valve, and a bit less side-to-side offset(the permatex did not dry hard, so it let me move it after loosening the screw).

2 or 3 tried did the trick. The bike is now back together and not leaking any gas out of the carb. Now I just need to get the throttle spiral adjusted correctly....

Anyway, I am wondering if the "soft" Permatex gasket sealer is going to keep the float in place-and if not, what I can use instead.....I'm tempted to drill a tiny hole or 2 in the float lever, and poke a couple of straight pins through the float and the hole, and bend them over at the end.....