interactive carburator map on my xj900 page

Hi Chaps,

currently I'm working on a interactive carburator map. It's in english too, well it's going to be. In case you like to help or you wanna take a look you'll find it here. Getting some pics of those nitty gritty parts would be helpful too.

http://www.xj900.kliwebdesign.de/vergaser01.php

 

Nice work, Ramon,

about pics you might wanna check out Alives extraordinay work here:

http://xjbikes.com/Forums/viewtopic/t=3 ... ikuni.html

 

Finno, that looks nice, very helpful! I would make the following suggestions:

a) The Jet Needle (or "Main Jet Needle") certainly does fit into the "Needle Jet", but for clarification pruposes, you might want to note that many people refer to it as the "Emulsion Tube", and that Yamaha calls it the "Main Nozzle" (which really should be called the "Main Jet Nozzle"). The Yamaha nomenclature is horribly confusing, especially for people who are first trying to leaarn about these carbs!

b) The "Pilot Screw" is usually referred to as either a "Pilot Mixture Screw" or "Idle Mixture Screw".

c) Along the same lines, you might want to label the "Diaphram" and "Spring" as "Piston Diaphram" and "Piston Spring", as both of those parts are directly related (and attached to!) the "Piston" (which you have labelled as a "Piston Valve" and which Yamaha refers to simply as a "Diaphram", acting as though the diaphram was the main descriptive function of the part, rather than acting as a vacuum slide piston!).


Beautiful site you have. Wish I knew how to read German........!

 

Where's the Enrichment Valve and the Starter Jet. Siphon Tube and well?

THOSE are where everybody runs into trouble with a bike that won't Cold Start!

 

Hi there, thanks for your reply. Made suggested changes.

"Where's the Enrichment Valve and the Starter Jet. Siphon Tube and well?"

Yes, what parts are these? Do I have them on my pic but not decribed?

 

Hitachi HSC32 and HSC33 carbs used such parts, and they are not in the cross-sectional diagram that you are using, which I assume you got from a factory Yamaha service manual, the XJCD, or a Haynes/Clymer manual (all of which lifted that diagram from a factory Yamaha manual). That diagram is very close, and is a good rough guide to a true Hitachi cut-away sectional view, but it is missing those key components (at least those components, maybe a few more upon closer study).

Don't be discouraged, though, it's a great intro for people who haven't torn into lots of Hitachi carbs. But you may want to note that such components are missing from the diagram, or try and find a good sectional view of a Hitachi carb (I don't know where to obtain such an animal........).

 

Also, I just looked at the updates (you're quick!), you might want to label the fuel jets as such, "Main FUEL Jet" and "Pilot FUEL Jet" to further distinguish them from their up-top cousins, the "Main AIR Jet" and the "Pilot AIR Jet". People tend to leave out the word "fuel" or "air" when talking about the jets, and say "you should have a #40 pilot jet".....well, there are two different pilot jets in the carb, pilot fuel and pilot air......you get the point.

Also, again, here in the States most people refer to the Pilot Mixture Screw as the "Idle Mixture Screw"......although "pilot mixture screw" is technically the correct name for it (Yamaha just calls it a "Pilot Screw"), this needle is, in practice, used to adjust the pilot circuit air/fuel mixture AT IDLE, and that's why the real-world name for the part is "idle mixture screw".

We're nit-picking, I know, but again---for people who are trying to learn about these carbs---maybe in an attempt to understand what they're going to be looking at when they take their own carbs apart for the first time....the differences in terminology can be VERY confusing at times. Many people use these terms interchangably, and without further clarification, a person may think there are more parts on the carb than there actually are (for instance: because one person mentioned adjusting the pilot mixture, another person said to tweak the pilot screw, and a third person tells you to set the idle mixture screw.....a "new" person might think there are 2 or three different screws to look for and adjust, when it's just a interchange of terminology being use to describe the same screw).

People who have gone to the dark-side and actually dug deeply into their carbs----which is the only way to PROPERLY rebuild them!!----already know what the parts are and are comfortable with whatever they are called (in fact, I make up my own names for many parts, like I call the starter jet "that stupid f****ing thing down in the bowl"......).

About the only truly confusing things/hard-to-remember about the Hitachi carbs are that:

a) the copper shim washer goes under the MAIN fuel jet, not the pilot fuel jet (it could physically fit under either), and.....

b) up top, the pilot air jet goes in the forward hole, the main air jet in the center hole. This is easier to remember if you recall that it's the same relative positioning (forward vs. back) as the main and pilot fuel jets down below...

c) the float pins into the carb with the black floats fitting upwards (towards the carb body) rather than hanging "down" into the float bowls!

 

And that the Pilot AIR Jet ... although it's the Pilot Air Jet and Not a Main Jet ... has the LARGER of the two Metering Ports. The Bigger Hole.

Unlike Fuel Jets which are the opposite!

 

Hello and again thank you for being nit-picking. Guess we have to cause many names are used for the same part all around. So I made another update including your suggestions. Consider that this should be a Mikuni BS35/BS36. Maybe I can introduce an overlay showing the real carb as a photo witg a low transparency. However let's make it real good even for beginners.
Let's collect information as much as possible and then I will see how this can be presented best. Hmmm, I think it's work for you too, cause you need to check each update....

 

They ought to have a Plastic Model ... like the Models that Doctors have inn their offices. So you can see the parts and get an idea of the interrelationship of the limited moving parts to the whole system.

 

OK, another update has been made. Please check.

http://www.xj900.kliwebdesign.de/vergaser01.php