Xs1100e Carbies

[petejw1966]

Carbie issues with mine are at the point where i'm about to burn the bloody thing! I have 3 sets of later carbs and could someone draw a pic of exactly where you measure the float hight? have been trying to find some BS36 carbs but to no avail, emails to wreckers in sydney and melbourne just don't get answered !! am at my witts end! Does anyone want a nice 78 std with heaps of new stuff, new tank, new paint, new tyres, with 4 basket case bikes to go?? cos if i can't get it sorted soon it's going! will replace it with something modern so i can go for a f-----g ride when i feel like it!!

can very much relate to that.  :-)
i cant remember reading anything about ur bike max,
whats happening with it?

[excess.11]

I agree Geoff........there is a reason for everything..........the fault simply has nt been identified  and it s a matter of elimination and logical thinking with test results.......
All it takes is time and perserverence.
I would love to be there to help out.....

If it was built in this world....it can be repaired in this world !!

I admire the efforts Maksy has gone to so far with what he s done.....
Fred recently posted what he had to do back in 1997 when he rebuilt his motor............a stellar effort re manufacturing valve guides and gears...

In the meantime..........let me tell you Maksy.......and anyone else that gets to the end of their patience regarding problems with these bikes.........
When you get them running as they should..........there is nothing else like it.
Buying a more modern bike does nt exempt the situation something can go wrong with that bike........and be just as painful.........and financially expensive  to repair.
You also have to relearn and resource all the knowledge associated with that bikes issues.

And where in the world would you get such a magnificent bike with "Heart and Character and Looks" ?

People approach me all the time to strike up a conversation when they see my bike......just as they did with fellow owners at the Rally.
You rarely get the same appeal with the public regarding newer bikes........

This appeal is not lost with  manufacturers either........hence their range of new vintage style bikes on offer.....

But there definately is no substitute for the real thing........

[steptoe]

that,s been done,,not sure what it will take,, ::)but we will win

[melbxs]

I'd definitely swap in a TCI from another bike. Takes 30 seconds and intermittent running issues are very much a TCI symptom.

[steptoe]

the three and the same,, although am thinking it,s been electrical from the start now,

are having trouble lining times up to start swapping things from both bikes, that,s all left to do,, process of eleimination and all that

[Jonesy]

Hey Max
is this the same set of carbs you and steptoe were fiddling around with several months back? looking at the air fuel screws or something.

[excess.11]

Maksy.....here s some references for you off our own site as well as the UK site.
I do recall seeing a line drawing somewhere relating to that.
I ll keep looking for you.....unless someone else helps out on that one.

http://xs1100.com.au/forum/index.php?topic=174.0

Ohhhh...silly me.....the line drawing is on page one of that topics postings.......

[makzy]

Carbie issues with mine are at the point where i'm about to burn the bloody thing! I have 3 sets of later carbs and could someone draw a pic of exactly where you measure the float hight? have been trying to find some BS36 carbs but to no avail, emails to wreckers in sydney and melbourne just don't get answered !! am at my witts end! Does anyone want a nice 78 std with heaps of new stuff, new tank, new paint, new tyres, with 4 basket case bikes to go?? cos if i can't get it sorted soon it's going! will replace it with something modern so i can go for a f-----g ride when i feel like it!!

[pgnz]

that "jetting guide" off the yank site is a crock

of crap, ignore it.  truth is two sizes up on main jet is maximum you go

on those 78E 34mm carbs, even then you're wanting a performance pipe and heaps of

extra airflow with it.   137.5 140 and 142.5 is where it's at.  140's are what you try first., 

145 and over is big drop in fuel milage and a drop in power with it

[petejw1966]

ive read all that before, ive had my carbs
off so many times and jetted rejetted and then jetted more,
all i needed to do in the end was bump the main jets up by 2,
and the bike ran very well, that was on the later carbs tho,

the early carbs id try the same thing anyway    bump the mains up by 2 sizes
and see how that goes,   142.5      i also used uni foam filters and ran them on the
outside of the stock rubber velocity stax from the air box.
with the vent t's, link them together and run a good length of hose, it
wont run as well down low as the later carbs but should run well enuff.
also make sure the float heights are set at the correct heights 25.7mm

[SCARFEY]

This doesnt translate to this format well because it was a table but you get the drift

Yamaha XS 1100 Carb Specs
 
Standards
                    
   US 78(E)   US 79(F)   US 80(G)   US 81(H)   2H9, 3X0, 3X1
                    
Type   BS34-II 2H7-00   BS34-II 2H7-10   BS34-III 3H5-00   BS34-III 3H5-01   BS34-II 2H9-0
Main Jet   137.5   137.5   115 / 120   115 / 120   132.5
Needle Jet **   X-2   X-2   X-2   X-2   X-2
Jet Needle   5GZ6   5GZ6   5IZ7   5IZ7   5Z1
Clip position   3rd groove   3rd groove   Fixed   Fixed   3rd groove
Pilot Jet   42.5   42.5   42.5   42.5   42.5
Starter Jet   40   32.5   26   25   32.5
Main air jet   140   140   140   140   140
Pilot air jet   180   180   185   185   180
Throttle valve   135   135   135   135   135
Pilot screw (turns out)   1¼   1¼   Preset   Preset   1¼
Float Height   25.7 ± 1 mm   25.7 ± 1 mm   23 mm   23 mm   25.7 ± 1 mm
Idle Speed   1050 - 1150 rpm   1050 - 1150 rpm   1100 rpm   1100 rpm   1050 - 1150 rpm
                    
      Specials      Sport   XJ
   US 79(SF)   US 80(SG)   US 81(SH)   5K7, RH   XJ1100 (J)
                    
Type   BS34-II 3H3-00   BS34-III 3J6-00   BS34-III 3J6-00   BS34-III 5K7-00   BS34/Hitachi/4 10M-00
Main Jet   137.5   110   110 / 120   110   112.5
Needle Jet **   X-2   X-2   X-2   X-2   X-2
Jet Needle   5GZ6   5GL16   5GL16   5GIZ30   5GLZ-34
Clip position   3rd groove   Fixed   Fixed   3rd groove   Fixed
Pilot Jet   42.5   42.5   42.5   40   47.5
Starter Jet   32.5   25   25   25   25
Main air jet   140   140   140   70   140
Pilot air jet   180   185   185   185   170
Throttle valve   135   135   135   135   N/A
Pilot screw (turns out)   1¼   Preset   Preset   Preset   Preset
Float Height   25.7 ± 1 mm   23.0 mm   23.0 mm   3± 1 mm*   3± 1 mm*
Idle Speed   1050 - 1150 rpm   1100 rpm   1100 rpm   1050 - 1150 rpm   1100 rpm
*Fuel level 3mm below the carb mixing chamber body edge.
** Emulsion tubes (needle jets) fitted to No. 2 & 3 carbs may have fewer holes.  Even though they have the same part number and X2 spec.  This apparently was aid in cooling the inner cylinders by having a slightly richer mixture.

[Clutch]

  G'day Scarfey,
 check my earlier post here, as far as I can tell std used the same carby right through but the RH had the later ( with the needle retained with screws and not a circlip in the slide, this is a bit of guess work as I have never seen the later).

   My experience with pods is with std jets ( although I never measured them to see if they had been modified by a P.O ) was that it will run well down low and accelerate well but runs out of puff around 120 -140 , once you get up around there you can only increase speed slowly.
   Needles set at second or last lean setting but always ran very rich ( plugs were always very black / sooty ).
 
 After fitting a std airbox ( with many thanks to Eddie )  with K&N filter, quick sync but no colour tune yet, big improvement up high and plugs are going back to a nice brownish colour.

  I don't know for certain but it may be to do with the float vents as Pete mentioned they are different as with std airbox they are connected back to the box but mine had been vented to atmosphere.

 will let you know how it goes with plugs and colourtune, this weekend if I have the time.

 clutch    aka....dave

[SCARFEY]

So based on all that if Ive got 137.5 jets I can go to 142.5 base on each increment being 2.5. Is that right??

[SCARFEY]

This is interesting......................

Motorcycle Carburetor Jetting Recommendations.

Copied from the xs11 list @ www.xs11.com This should give you an idea of which way to go in regard to different Intake Exhaust configurations.

 

Note:

This document is based on Mikuni Carburetors. But the theory follows through on all carburetors. Be aware that Mikuni Main jets increment in steps of 2.5, Hitachi Main jets increment in steps of 2.0. Hitachi Main jets (screw in style [Yamaha XJ's] are available in sizes from 110-134 in increments of 2.0. All this means that if you find you need to go up 4 steps on the main jets according to this chart (2.5x4) the step up would be 10.0. For Hitachi mains the step up would be 5 jet sizes (2.0x5) since following this chart for Hitachi mains would put you at 8.0 which is very close to 7.5 which would be 3 steps according to this chart.



Jetting Recommendations
by Denny Zander

Here is a simple set of jetting guidelines that have worked for me. For those considering jet changes, this might help select a starting point.

1 jet size for custom 4 into 2 exhaust

2 jet sizes for 4 into 1 exhaust

1 jet size for K&N filter (single inside airbox)

1 jet size for drilling out the bottom of the airbox

2 jet sizes for both single K&N and drilled airbox

2 jet sizes for individual filters

2 jet sizes for no muffler (open header)

1 pilot jet size for every 3 main jet size increase

Add up all the jet size increases and subtract one. (Remember they go in steps of 2.5 for each jet size)

Under a mismatch condition, like individual filters and stock exhaust or 4 into 1 header with stock filter and air box, subtract an additional 1 jet size.

Check plug color often, sync carbs after each jet change, make sure the floats are set correctly, and seriously consider purchasing a Colour Tune. (See "Colortuning Carburetors" in the Maintenance Section).

Make sure your carbs are in perfect working order before making jet changes.

Example from my '79 XS1100 F:
Stock main jets: 137.5

Stock pilot jets: 42.5

2 sizes for 4:1 exhaust (Jardine)

1 size for single K&N

1 size for drilled air box

4 (main sizes) - 1 = 3 or 137.5 + (2.5 * 3) = 145.0
1 (pilot jet size) or 42.5 + (2.5 * 1) = 45.0

With this jet configuration I get 32-38 mpg on the open road, Smooth idle, very strong exceleration from off idle to 80+ mph, and steady pull past 120 mph. My "F" has 65K mile on it, of which I have put 33K with this jet configuration.

I have applied this to the '78-'79 carb set with great success. These guidelines should work for the '80-'81 carbs also. The only part I have not tested is pilot jet changing on the second generation carbs.

Happy Jetting

Additional info: decrease main jet size one step per 2000' above sea level

[SCARFEY]

Thanks for the advice

The engine is a "G"

 I'm not sure what the carbies are off. Probably the "E" I have in the spares department.

I have another set [painted black] possibly off the "G" engine.