48U – Linkert Bowl & Float Alignment

[wideglide38]

I’m having trouble with fuel leaking from the bowl (M51 setup) on a ‘48U. Carb has the brass float and round steel tipped needle in brass seat (single square-type hole machined in seat tube for fuel delivery). I have pulled apart a dozen times, reassembled, only to have fuel run out carb throat & vent hole backing the venturi. I’ve tried the rubber-tipped needle and rubber ducky float as well same issue. I successfully stopped leaking (original components) and after rebuilding I let her sit over night (bowl full & shut off rod closed) – no leaks or wet carb/bowl the next morning. I rode to a watering hole (18 miles away – 7/8 full tanks) and parked her – no leaks down or sitting. On the way home, she lost power and I look down at carb and fuel was running out of the carb, even pissing out the small vent hole in brass cap over the needle/inlet like Old Faithful. I think my float is hanging up on the carb body through the float (yep, the float screw was tight).

I followed the float set-up with the offset (attachment). I assume float offset setup is same for both OHV and SV? I’ve checked for leakage (bowl upside down and could not suck air through the inlet fitting). The U has a lot going on under the carb (spark advance cable, speedo cable, tank shift rod, fuel filter/inlet line and cylinder fins) so there’s not much room to rotate the bowl. Anyone know where the sweet spot is for fuel inlet alignment?
Thanks,
William

[41craig]

Wideglide38; If you have a Kokesh brass float, the setting is different than stock. They are heavier than the cork float. Attached is the setting that came with the Kokesh floats. If your float is Taiwan, then check your float. I have seen many pin holes in them.
Craigimage0.jpg

[T. Cotten]

Wideglide38; If you have a Kokesh brass float, the setting is different than stock. They are heavier than the cork float. Attached is the setting that came with the Kokesh floats. If your float is Taiwan, then check your float. I have seen many pin holes in them.
Craig[ATTACH=CONFIG]24236[/ATTACH]

Wow Craig!

The float looks upside down!
(Shouldn't it at least be level?)

Kokesh's were ~13g, and Eversure's (DIXIE) were ~11g, and OEM was ~3g.

Brass floats don't.

....Cotten
PS: William!

With any float, the only way to set up the bowl with certainty is if you have both carb body and bowl in hand, so you can invert it for the suck test.

With a sidevalve model, the pivotnut screw will need to be at the end of the lever slot, and the float often offset as far as possible to leave at least an eighth of inch of clearance with the side of the bowl.
(Slop in the lever upon its pin is another issue.)

Note also, the bowl should be indexed with the valve portion under the power needle, or closer to the choke assembly when possible.

[41craig]

Cotten; I'm guessing that Kokesh didn't employ any of Rembrandt's offspring to draw the float bowl.
Craig

[duffeycycles]

I never got a Kokesh to work above 3/8" without running over.
They also lasted about 4 yrs max before they got pinholes.

[wideglide38]

Thanks Guys for all the good comments & advice.

Craig - not sure source of brass float. It’s not heavy with fuel or sloshing. Looks soldered well.

Cotten - Thanks, makes sense testing carb/bowl together. I was lazy & didn’t wanna pull the carb. Float level was set at 5/16” since I knew it was heavier than cork. Float screw was set in center of lever hole and (roughly) 3/64th offset. For indexing, I had heard same at/under the power needle; my problem is the straight shift rod down to the trans prohibits placing fuel inlet under or near the power needle. Maybe I have the wrong rod.

Mark - appreciate the height. Need to set my float no less than 3/8”.

[T. Cotten]

Cotten; I'm guessing that Kokesh didn't employ any of Rembrandt's offspring to draw the float bowl.
Craig

It must have been the inspiration, Craig,...

For all the Tedd "beanpots" on ebay with the float upside down.

(Its bad enough that they think its an HD bowl!)

I never got a Kokesh to work above 3/8" without running over.
They also lasted about 4 yrs max before they got pinholes.

And Duffey!

I never found a Kokesh that 'pinholed', but plenty of Dixies.
And then there were those productions where the screw wasn't sealed.

The real mystery is why anyone would produce nitrophyll floats that are just as heavy!
(Shown on the bottom of my D-port display; I've a horseshoe Schebler float on the bench that is only a modest twice as heavy as it should be...)

The age-old question: If you're going to the trouble to make something, why not make it right?

Thanks Guys for all the good comments & advice.

Craig - not sure source of brass float. It’s not heavy with fuel or sloshing. Looks soldered well.

Cotten - Thanks, makes sense testing carb/bowl together. I was lazy & didn’t wanna pull the carb. Float level was set at 5/16” since I knew it was heavier than cork. Float screw was set in center of lever hole and (roughly) 3/64th offset. For indexing, I had heard same at/under the power needle; my problem is the straight shift rod down to the trans prohibits placing fuel inlet under or near the power needle. Maybe I have the wrong rod.

Mark - appreciate the height. Need to set my float no less than 3/8”.

WLA folks always face the shift rod issue, William!

But I set up a '41 UL no problem.

When you have the assembly off for certainty, you may find that you have to relieve the bowlstem to allow indexing at 90° to the body.
I use a dry-erase marker to find the interference.

You'd save yourself grief, as well as fuel mileage and overall performance, by putting that brass boatanchor on the wall.

....Cotten

[tfburke3]

I dont rely on any method to determine final fuel level,not float level,other than holding a piece of gasket paper over the stem hole while the disconnected bowl is in my hand,connected to the fuel line.
Open petcock and flow, fuel level and any seat leakage,slowly rising level, can be can be observed.Then with level proper and holding you can install and index.
Tom

[aumick10]

One way i have used before is to remove the drain plug, install a barbed hose fitting with a piece of clear hose. Tie the hose so it is above the carb, then turn of the fuel.
This will show you the rate of filling, plus the actual fuel level when the carb is completely assembled.
Is the float level set on a side stand or upright, if you do it on a bike?
Cheers,
Mick

[T. Cotten]

C'mon Folks,...

What fuel level do you use, and how do you accurately measure it?

I found that it "leaps" up to a dial caliper, and reproduceability is nil.

So I made a sight gauge, and found that surface tension affected it too!

....Cotten
PS: I need somebody to 3-D print me a clear body and bowl.

[duffeycycles]

I have used the tube outside to look at fuel level also.
You have to understand that verticle height above if not on the bike hooked to the system is important to how fast they fill the bowl.
My brother used this method 35 years ago when first using the brass floats.
The faster it goes in changes the level without changing the float height.
Also,not all bowls have the drain.
It is much easier with a consistent weight light nytrofil float like Cotton sells

[T. Cotten]

I guess you mean 'head pressure', Duffey?

To produce six different floats accurately, I had to measure the resulting fuel level from as many NOS floats as I could.

Both DLXs and Linkerts appear to be designed with a fuel level 5/8" from the top of the bowl.
If you sink a boatanchor float deep enough to achieve that, you've lost most of the available 'reserve' to the volume of the float.
And brasses and the nitrophyl boatanchor are even fatter than OEM.

Reserve is why there is a bowl.
(And racers needed even more; "pregnant bowl" courtesy of http://www.beautyofspeed.com/)

....Cotten
PS: I found that too small of a tube for the sightglass drew its level higher than inside the bowl.

[duffeycycles]

To some degree I agree 100% with that
The float does drop & open the valve at a different level than a lighter float so to some degree they still work,but your engine longevity depends on it!!!
I do agree it is much better with a lighter float

[T. Cotten]

And I almost agree with you, Duffey!

But I hope the opening and closing would still give 5/8" in the bowl, when the valve is shut.

A heavy float would certainly respond more sluggishly, giving it's 'toilet cycle' refill a lot of amplitude.
A buoyant float would keep the lean and rich periods closer to a straight line.

And that's where fuel economy benefits; Not sure how that affects the motor....

....Cotten
PS: Mick!
Where did you find a 1/4"-32 barbed hose fitting! Hospital dumpster?

[wideglide38]

I received Cotten’s floats last week (Thanks Cotton) so I pulled the M51 off the bike this weekend. The brass float I installed developed a sudden thirst for gas and she became a sinker. I looked all over the brass float, no apparent pin holes or solder breakdown…..maybe the fuel got in where the float is depressed for the screw mount!?!?

Secondly, the brass bowl valve cover cap (27390-33) has a small vent hole. Was the vent hole year specific? I looked through all my caps – no vent hole in any. Searched the web and found no cap with a vent hole. Maybe someone drilled the cap.

Thanks, William