M51 for a 46WL

[Austy]

I picked up a Linkert M51, 3 Line, for my 46 WL as from what I have read it is the correct carb for this year and model. Since I restored this bike almost 30 years ago, I have been running an M88 Linkert on the bike with no issues. The M51 came with a crab bowl that sits entirely flat against the bottom of the carb which if I am not mistaken is actually for OHV model motors. The M88 has a carb bowl that sits with the needle and seat offset from the carb with a raised portion that has a nut on top.

So, the two question I have are: 1) When I set this carb up to put it on my 46 WL do I set it up with a Side Valve Bowl just like the M88 or with the bowl that came with the carb?? 2) Should this carb be painted black or left raw brass?? Thanks for the help

[T. Cotten]

Your instincts are good, Austy!

It needs the sidevalve bowl, and painted black.

(The most fuel resistant was https://sigmfg.com/. I have yet to see evidence that L&L ever produced a bare body.)

I have observed earlier M51s machined for the OHV bowl, and even dowel holes. But my late example on the wall is not; Photos would be appreciated!

....Cotten

[Austy]

Thank you Cotton. Well apparently, the 1 that I picked up must have been machined at some point flat across the entire bottom of the carb to accept the OHV bowl and has 2 dowel pins that sit on either side of the bowl where the needle and seat are set. So, I take it from what you are saying is that the M51's were actually machined like the bottom of the M88 Carbs to accept the SV Bowls only?? Well that sucks!!!

[T. Cotten]

..Well apparently, the 1 that I picked up must have been machined at some point flat across the entire bottom of the carb to accept the OHV bowl and has 2 dowel pins that sit on either side of the bowl where the needle and seat are set.

We don't know when L&L stopped machining them, Austy!

So your later example may be our best clue, and that's why we need good pics....

So, I take it from what you are saying is that the M51's were actually machined like the bottom of the M88 Carbs to accept the SV Bowls only??

M88s were machined like virtually every other SV carb. The exceptions are early M51s, with a meatier casting to accept the OHV bowl, matching the contemporary M5. Apparently, it continued into the 3-line era, which your pics might show us, by numbers, etc.

Well that sucks!!!

Don't throw the OHV bowl away.

....Cotten

[Rubone]

My guess is it is a late replacement body which could also have been stamped as an M55 for OHV use and was machined to work for either end user.

[Austy]

[Austy]

Sorry forgot to attach what was what. These 3 pics are of the M51 and it appears as if it was machined from the get to accept either the SV or OHV Float Bowl

[Austy]

This picture is of the bottom side of an M88 Carb and it is only machined to accept the SV Float bowl

[Austy]

1st time ever posting any pictures here so forgive me everyone.

[T. Cotten]

We need to see the casting number on the 'idle' side, Austy!

(Please note that even 3-348 castings will have different conformities, such as: Is the '4' stamped on a pad while the others are cast, or are they all cast in the pattern?)

And the machined gasket surface is much easier to observe with the gasket removed....

....Cotten
PS: That's a mid-'50s replacement HS needle for OHVs with a 45º point, probably works, but the SV angle is 30º; Choke lever subject to change I bet... and maybe the throttlelever, if "correct" demands it.

PPS: A SV bowl will "fit" upon an OHV carb, but an OHV bowl will only fit upon those odd SV examples machined such as yours. The machined M51s I have encountered were drilled, but did not have dowels installed.

[Austy]

M51 Idle side and bottom with the gasket removed. Should have had my glasses on when I took that 2nd pic, LOL

[T. Cotten]

I fear, Austy,...

We shall have to add it to the endless Linkert Mystery List!

Meanwhile, I suspect your small LS knob is later, and it originally came with a thin spring collar.

And that military chokelever might hit your aircleaner.

.....Cotten

[Austy]

Thank you Cotton for your help and attention to the details of the photos, very much appreciated. Yes, no doubt the choke lever will need to be replaced with the proper 1. A few other items will need to be replaced to make sure that they are correct and get it as close to correct as possible before it gets put on the bike.

[T. Cotten]

Please beware, Austy,..

Just making them AMCA "correct" doesn't always make them run.

But I always preached that to my customers anyway.

....Cotten