Archive for the ‘Carbs’ Category

XS650: Carbs … Dell orto   Leave a comment

Over a few biers and bullshit-i dont drink the topic turned to Dell’Orto carbs…was interesting so i started taking notes as i have thought about going there myself…i havent tried these so dont take this as gospel.

The general consensus was that PHF DD-destra or right and PHF DS-sinistra or left as 30, 32, 34mm are better suited for the XS, some have used 36, 38 40mm versions but found them over the top…get them paired DD and DS otherwise setting problems arise.

The 32 and 34mm versions were successfully mounted in XS-SE 650 and SR 500 manifolds, the SE 650 had the advantage that vacuum barbs are present-unless you have done Gorans vacuum port mod.

For second hand carbs look for ducati or guzzi models

  • lever choke not cable, and is only required on the LHS
  • you want the models with the round plastic or alu cover, not the tubes, cables enter at 45° or 75°, some have side cable mounts and are better for space
  • get the version with an accelerator pump
  • brace against vibration
  • use softer return springs
  • get the 2 into 1 cable fittings as found on Ducati California III and Guzzi Le Mans IV

Some Info: XS650 Dellorto

this old tractor some info here too…dont really find this too interesting though

ducati meccanica interesting site…the following are found there

dellorto tuning guide

factory jetting guide

dellorto jetting/dellorto parts book

needles charts

setting float levels

factory set-up for singles

PHF parts list and diagramme

from stein-dinse.de

needle chart PHF

slides

jets

from dell orto

english version of manual found here

some settings
PHF32
Slide…………….60-3….50-3….50-3….50-3….70-2
Idle jet…………….50…….57…….55……….. ……57
Main jet………….170.. …125…..125…..135…..125-130
Atomiser…………265……262…..265………. …..262
Needle……………K16……..K6…..K18…….. ……..K6
Starter jet………..75……..75…….80…………… ….
Needle Ventile..250……250….250…………….. ..
Pump jet…………..?………35……..35……….. ……..
Float………………………………….10g @ 18mm

………………..PHF30………………PHF36
Slide………………………………………..50-3
Idle jet………..55……………………….57
Main jet……..125…………………….120
Needle……….K23-mid setting…..K5-top setting
Atomiser…….262……………………262
Float…………8.5g

– dont forget this was liberally lubricated with mind altering substances so reader beware.

 

1 .. dell orto PHF36 ... from Kalle ... says they fit like they belong

dell orto PHF36 … from Kalle … says they fit like they belong

 

2 .. dell orto PHF30

dell orto PHF30

Posted January 10, 2011 by xscafe in Carb - Dellorto

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XS650: Carbs … Mikuni   Leave a comment

I’m not a carb expert. I can strip, clean and tune my own carbs fine but if I was relying on my powers of fine tuning for a living I’d be in trouble. It’s just as well the original CV carbs are fairly straight forward.

Many of their problems are related to dirty tanks leading to blocked Pilot circuits, float valve, float level setting, airleaks in vacuum barbs, boots, butterfly shaft or air filter.

Good discussions of these have come out of the Garage.

Mikuni_BS-CV_Carburetor_Rebuild_Tutorial … a nice pictorial guide

BS34 and BS38

VM 34-36 Roundslide Mikuni

Here is a Mikuni VM manual

vm carbtune

Interesting read on CV carb setting up

Basic carb theory

 

jet crossover

 

Repair hints

Sudco

VM Jetting chart

Topham resource site

2 types of original carbs, both CV, see the Oz site too

  • BS38 – early types were not linked and bolted perpendicular to the head, later models were linked and the boots were angled to the head
  • BS34 – linked and angled to the head

 

Basic CV carb ID pics

 

US XS650 carb guide

 

pilot jets

 

float setting

 

CV cut-away

 

CV schematic … BS34 pilot jets are fed directly from the main so must be plugged

 

VM dimensions

 

Goran Perssons vacuum port mod

 

This is handy for providing vacuum points to balance your carbs if using boots without vacuum barbs, simply plug when not being used.

Posted January 10, 2011 by xscafe in Carb - Boots, Carb - BS, Carb - VM

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XS650: Carb Boots and Diaphragms   1 comment

Some time ago I had to rebuild my carbs, BS34s from a 3L1 motor, was really no big deal, they had been sitting a while so I cleaned them and tarted em up. Rejetted, new needles. boots, diaphragms etc.

The original Yamaha boots were hard and cracking after just 30 odd years. Anyway I ordered new boots etc and installed the carbs. After 3 months the boots had cracked to shit on the outside and begun to melt on the inside. WTF? And European fuels dont have the same ethanol content as North American-I see the other day that this will be changing in the near future. This was my first experience with that particular supplier I cant even bring myself to name, but we all know who he is with his cheap chinese crap.

 

1 .. damage like this

damage like this

 

2 .. and this

and this

 

Anyway, to cut a short story longer, JBM Industries came to the rescue. Theyve been making stuff for the aircraft industry.

These boots dont use the original metal cage and will secure your carbs unsupported. They make BS38 boots both straight and angled flange and BS34 boots. Also the diaphragms.

 

3 .. NOTE. These will have no problems with ethanol containing fuels.

NOTE. These will have no problems with ethanol containing fuels.

My BS38s are running great. It’s a shame as I prefer the BS34s. I guess it’s good that Paypal is my friend.

JBM’s first carb diaphragms were for our Mikuni CV BS 38mm. Next were those for the BS 34’s. They’ve gone on to design and manufacture parts and compression molding tooling for a variety of vintage motorcycle carburetors. Don James, head of JBM, uses only a specified quality TSR heat cured compression molded rubber compound. (Not that crap recycled, zero quality control crap we are becoming used to from my favourite low service partner). Molds, tooling and production are all done ‘in house’.

TSR … Technically Specified Rubber, a system for describing rubber compound formulations. Graded according to dirt, ash, nitrogen, volatile matter content and the Plasticity Retention Index (PRI).

A first rate design, tooling and molding operation with excellent customer service!

Cost is very reasonable. Reflects a lack of ‘middlemen, mark-up merchants’  (distribution/wholesale/retail links). Products sold directly at a reasonable margin to the customer/user. A sound business model.

JBM Industries – thumbs-up – keep up the good work guys.

Posted January 10, 2011 by xscafe in Carb - Boots

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