New Carburattors

nb · #1 23 Apr 2004

Hello,
I hope to get more success with this topic than my first one.... ;-))
A friend give a pair of carbs for an old kawasaki (a 500cc ninja I think) and they are 34mm, almost the same that my 32mm Bing from the G/S. The japanese carbs sounds like unbrakeable and almost never adjust.
Well any experience or advice it`s welcome.
Cheers.

nb.

**Grant Johnson** · #2 23 Apr 2004

I would NOT recommend making the swap. It's harder than you think to get it right.

The stock carbs are actually very good on a G/S. The only adjustments I have regularly made have been occasional cable synching. And guess what - you'll have to do the exact same thing on the Japanase carbs for the exact same reason - two long cables, which will never wear exactly the same.

About once every 50,000 miles you should strip the carbs and check the float needle for ANY sign of wear and replace if needed. The slide needle and needle jet should also be replaced at the same time.

Replace the "choke" assembly gasket and tighten the screws well. They have a habit of loosening. A dab of silicone seal on the screw heads/body junction helps.

Check the diaphragm carefully for pinholes. Replace at 100,000 km for sure.

Set the float level carefully, and adjust the pilot screw and idle and cable synch, and they're good for another 50,000 miles. Adjust the cable synch about every 5-10,000km. depending on how it's running and how fussy you are.

Most complaints I hear about the stock Bing carbs are when they have not been maintained properly or at all.

Due to the low mounting postion they are vulnerable to getting water in the float bowls - drain and dump out regularly in bad weather. Nice and easy with the Bings, a pain with Japanese carbs!

Good luck!

------------------
Grant Johnson

Seek, and ye shall find.
------------------------

One world, Two wheels.
www.HorizonsUnlimited.com

nb · #3 23 Apr 2004

Hi Grant,

Don`t you know the correct messures for my bings? Jet neddle, slide middle, main jet, etc. I`m trying to buy to Motorbins or Motorworks a pack for overhaul the carbs but I'dont know what...I have to save money....

Apart from that, I don`t know the correct way to set up floating level, exist a method?

To be honest since I repair the bike I didn`t pay much attention to the carbs, you have right the easier way was think of change the carbs.

Thanks Grant.
Nicolas.

**Grant Johnson** · #4 24 Apr 2004

Go to your BMW dealer, or buy a manual from Haynes for instance if you don't have one.

You MUST have a service manual to do your own work.

All the specs will be in there, including how to set the float level.

You should be able to tell Motobins what model you have and the serial number! - and they should be able to supply correct parts.

------------------
Grant Johnson

Seek, and ye shall find.
------------------------

One world, Two wheels.
www.HorizonsUnlimited.com

nb · #5 24 Apr 2004

I ask you this for a reazon:

Clymer: main jet 130, slide needle in 3rd position, Owner Manual main jet 145, slide needle 2.64 pisition 4.
I can't get a Haynes yet. In carburation aspects in my country almost everyone has his own combination for a same carburator, I thought that you maybe have your own. Here doesn't exist BMW mechanics for 2v, only in buenos Aires 330kms from here. So I don't what to do.

Thanks anyway Grant.
nicolas.

**Grant Johnson** · #6 24 Apr 2004

Go by the owners manual, always. ASSuming the bike is stock - exhaust, carbs, etc.

Should work fine.

Set the float level so that the seam on the float is horizontal when the valve just closes off the gas flow. Do it with the carb off the bike and very carefully horizontally and vertically oriented straight!

------------------
Grant Johnson

Seek, and ye shall find.
------------------------

One world, Two wheels.
www.HorizonsUnlimited.com

**bryan** · #7 27 Apr 2004

Hi Nicolas,
i have some info re 80g/s carbs...the settings/jets/needles did vary from '81-'86
if you e-mail me what year your bike /carbs are i'll send you the info i have.
i know from experience

the needles etc..are not fully interchangable....so it's important to order for the correct year
bryan

**John Roberts** · #8 27 Feb 2005

I've just e-mailed bryan as follows.............

Hi Bryan,

I've just seen your reply to nb's thread re new carburators back in April last year, where you said you had information about carb settings. As my bike, an '82 R100RS BMW has done 55,000miles (90,000km) I am changing the needles and jets as Grant and others say that they will be worn by now, and I'm getting in the low 30's mpg, although, to be honest, it has always been around that figure. There are two different positions quoted between the BMW workshop manual, the Rider's Hanbook and Haynes' Manual, but none of them say how the notches in the needle are numbered i.e. whether the top notch is no.1 or if it's the bottom notch.

Briefly:
BMW R100RS
First registered Sept 1982
Believed manufactured late 1981
Frame and Engine no. 6079524
Inclined Bing constant-depression

You did say to nb to e-mail you, so I hope it's ok for me to do so too. I'll put this as a new thread on the HUBB as well in case you've changed e-mail address.

Many thanks

John
......................................
Does anyone else know, please?
J.

[This message has been edited by John Roberts (edited 27 February 2005).]

**Grant Johnson** · #9 27 Feb 2005

Needles are always numbered from the top.

In other words, putting clip in the top notch means you're in notch #1, the LEANest position.

(Easy to remember which is lean and rich - the needle PLUGS the hole more or less. Less fuel of course means leaner.)

**John Roberts** · #10 27 Feb 2005

Grant,
Again, my thanks.
John

**dc lindberg** · #11 25 Sep 2008

How did it go ?
What happened ?
How did they operate ?

I have dell'orto PHM 40mm to my summerbike. Far better than Bing (my personal opinion).
Try get the correct info on from which Kawa they came. I would like to look into it to. Was it Keihan or Mikuni carbs; slide/throttel or CV ?