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Euro Jetting

Started by Night Vision, February 20, 2007, 10:24:20 PM

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Night Vision

I found this and thought it was interesting. Keep in mind that the Euro's did not have the vacuum modified flapper. I believe they also had the stumble....

"IM Translator 3.0" translation/interpretation is in blue.
Feel free to add any corrections or insights.....

Hauptdüsen main jets
Vorn front   : #130 (Deutschland) (Germany)
                   #122,5 (andere Staaten) (other states)
Hinten rear   : #135 (Deutschland) (Germany)
                   #127,5 (andere Staaten) (other states)
   
Leerlaufdüse pilot jet    : #60
Leerlauf-Luftdüse air pilot jets   : #130 (Deutschland) (Germany)
                                              #120 (andere Staaten) (other states)
Leerlaufschraube pilot screws   : 2  ± ½ Drehung rotation
Leerlaufdrehzal RPM?   : 1100  ± 50 U/min

Might be worth trying on a twin nickled un-modded carb V (like my brothers  ::) ). All I'd have to do is swap the mains to 130/135, keep the air pilots at 130/130, count out his pilot screws (so I could put it back to where it is) put them at 2.5 and see if he notices anything when he picks up his bike this spring.............  8) 8) 8)  ;D ;D


if it ain't worth doing it the hard way....
it ain't worth doing it at all - Man Law
;D


if it ain't broke..... take it apart and find out why


don't give up.... don't ever give up - Jimmy Valvano

Lucky

I believe Leerlauf translates to "idle"...
1982/3 XZ550 Touring Vison, Gold on Black

tremalzo

Quote from: Lucky on February 20, 2007, 11:06:59 PM
I believe Leerlauf translates to "idle"...

Your translation is correct: leerlauf = idle.


XZv2

#3
Hi, Night Vision and Tremalzo,
The 82 Yamaha Service Manual for the Euro version XZ550 gives some more and slightly different information on page 8-10 than yours:

The carbs for 11 specified Euro countries (that is France, Holland, Belgium, Denmark, Switserland, Sweden, Austria, Norway, Finland, England and Italy) have  BD34 Mikuni carbs with I.D. Mark 11J-01.
The carbs for the 12th Euro country, Germany, are also BD34 Mikunis but they have an I.D. Mark 11V-01.
The main jets for the 11 specified Euro countries are 122.5 front and 127.5 rear, but for Germany 130 front and rear.
The throttle valve for the 11 countries is 120, for Germany 125
The air jets are 120 for the 11 countries and 130 for Germany.
Also vacuum pressure at idling speed is different for the German models (Above 220 mm Hg for Germany, above 180 for the others).

So it seems German carburettors had a number of different parts and settings. According to tests, German XZ's also stumbled....
XZv2

   

Night Vision

XZv2, thanks for that info... I had forgotten that we have the 36mm carbs and the Euros have 34mm.

My wife even knows they are 36mm  :o [ I now have new glasses... a little inside joke between me and XZv2]

Now I'm not sure the German settings will work good in our 36mm carbs....

.......only one way to find out  :)
if it ain't worth doing it the hard way....
it ain't worth doing it at all - Man Law
;D


if it ain't broke..... take it apart and find out why


don't give up.... don't ever give up - Jimmy Valvano

XZv2

Hi, NightVision,
All 82 XZ550 models, the US, Euro and East Asia models, have the 34 carbs, the 83 the 36. Even the XZ400 has the 34.
XZv2

Night Vision

are you sure US 82 aren't 36mm?

this says they are... http://www.ridersofvision.net/News/RoadTest/roadtest.html

where is it measured? I just measured two set of 82 carbs (the inside throat where it goes into the manifold boots) and got 36mm on both
if it ain't worth doing it the hard way....
it ain't worth doing it at all - Man Law
;D


if it ain't broke..... take it apart and find out why


don't give up.... don't ever give up - Jimmy Valvano

Walt_M.

Measured at the throttle plates, the '82s are 34mm. Doesn't matter what the biggest opening is, just the smallest.
Whale oil beef hooked!

Glyn

Does anyone know if the Mikuni jets relate to their metric internal bore. ie 130 = 1.30 mm, or does it relate to rate of fuel flow?

XZv2

#9
Yes, Night Vision, you are right, the test gives 36 mm for the RJ, but that is not correct.
On page 98 Haynes gives the Mikuni numbers: BD34 for the 82 RJ and BD36 for the 83 RK. That is the same number as the 82 Yamaha Service Manual gives for the Euro 82 XZ550: BD34.
That Mikuni number is related the internal diameter and indeed I also measure 34 mm for the 82 Euro carbs at the throttle plate.
I have no 83 carbs to measure these.
Glyn, old German Bing carbs of the Fiftees and Sixtees indeed had the 100 number for 1 mm diameter, but I don't know if Mikuni uses the same system.
XZv2

Night Vision

yep, I measured the butterfly and it's around 34mm

the specs printed in the road test data are wrong... some stuff in the Haynes manual is wrong...

guess it's a good idea to check with the experts here before believing everthing you read

goodie.... now I just might try that jetting
if it ain't worth doing it the hard way....
it ain't worth doing it at all - Man Law
;D


if it ain't broke..... take it apart and find out why


don't give up.... don't ever give up - Jimmy Valvano

XZv2

Yes, NightVision, some data are incorrect. Fortunately most data in the manuals are correct, 99% or more, fortunately.
I did not believe the Haynes manual when it stated that there is a 70 teeth camwheel in the gear box. I found that the Yamaha Service Manual confirmed this. Taking apart the gear box and counting the teeth it turned out to be 30 teeth.

If you try the German carb settings, take into account that the German carbs use a throttle valve # 125 in stead of the 120 that all other countries (Euro and US) have for the 1982 BD34 carbs.
Probably the jets and settings are only OK in combination with that throttle valve.
XZv2

Brian Moffet

I just did a rough measurement on the bottoms of my carbs (which are 83).  They measure 36 mm.  They don't look like they get smaller, but I didn't do a careful measurement (just procrastinating from mowing the lawn)

Brian

XZv2

Wow, mowing the lawn. It's winter here, I did not mowe the lawn since October! XZv2

h2olawyer

I'd have use the snowblower to remove 6 to 18 inches of snow from my front yard before I could even think about mowing.  Plus, the ground is so saturated by the snowmelt, it would take several days before things were dry enough.  Never mind that my lawn went dormant last September so the mower blades wouldn't cut anything anyway.  May be mowing here sometime in April.

H2O
If you have an accident on a motorcycle, it's always your fault. Tough call, but it has to be that way. You're in the right, and dead -on a bike. The principle is not to have any accident. If you're involved in an an accident, it's because you did not anticipate. Then, by default, you failed.