Anyone tried to put XJR carbs on an XS11?

[janwic]

Hi guys,

Tired of trying to figure out which float it is that always gets stuck, and inspired by Piet's post "zur Verbrauchsreduzierung rate ich zum Einbau des Vergasers der XJR1200/1300" (now isn't that poetry ) I bought a set of XJR 1300 carbs for my XS11 today. With the carbs on the table, Piet's post on the computer, and armed with a German Tech dictionary I started my research on what must be the world of motorcycle's equivalent of heart transplant. Unfortunately, it turned out that 'drosselklappensensor' was not a great hype in 1969, the year my dictionary was printed. Also, I figured out that "Eine 6mm Schraube nehmen und ein 1mm Loch reinbohren" must mean 'grab a 6mm screw and drill a 1mm hole' but to me, that knowledge seems to be only a part of the puzzle. What do I do after I grabbed the screw? Where am I supposed to drill the hole?

Now to the question, which I perhaps should have put before investing $300 in the new carbs, has anybody (not counting the German who originally did the 'Verbrauchsreduzierung'-posting which Piet helped us to) done this before? The Truth must be out there... Also, would anybody be interested of me posting pics of my attempt to repeat Barnard's triumph in our wonderful XS11 realm? If I fail, it would be useful to document how to not..., don't you think?

/Jan

[RS Thornton]

I am always interested when others are making modifications, but my first questions is why? I am not familiar with the xjr1300 carbs so what is the expected improvement?

[janwic]

Now that is a valid question. According to Piet, "you can take the carbs from the yamaha xjr1200/1300 it boost your power to 108 horsepowers with a bit lower fuel consumption too". But what I hope to get out of this is, on the first hand to make my XS no longer suffer from the stuck float disease, which combined with the malfunctioning fuel petcock syndrome makes fuel end up on the garage floor which is not a great thing if the garage is in the house. Also, I hope this will solve the hesitant behavior (in search of better words) of the bike around 1/4 of throttle. That is when all the floats float. When one float is stuck, the bike runs like a moped, with attention-raising explosions from the flooding fuel passing through the cylinder and igniting in the exhaust. Yes, I know - a true mechanic would have worked it out. The last thing I did before I stored the bike for winter was to check that the floats were floating. Now one is stuck - gaaaaaahh!

[DiverRay]

The sticking float is an easy fix. Just pull the carbs, flip them over, verify all floats, that is 8, 2 per carb, are the same. Then check the pin for buildup of old gas, etc. Clean as needed, and you should have no problems.

As far as the transplant, measure the distance between the throat center line on the XS and XJ carbs, and adjust by redrilling mount holes, or changing the mounts/brackets between carbs. All you are trying to do is fit the brace of 4 carbs onto the XS head. I have not done that, but it can't be that hard to engineer.

Ray

[RS Thornton]

What Ray said...

I think it would be a lot easier to clean up the pins and get the floats working properly than swap the carbs.

But I am hoping you do the carb swap just becuase I think that kind of work is pretty cool, especially when someone else is figuring out how to do it.

[Geezer]

I agree with the jerky on/off throttle at around 1/4 throttle and mostly in lower gears. I have a set of KZ1000 slide/needle carbs that I'd like to try on one of my XS11s for the same reason but I doubt it would improve mileage.

I studied German for 3 years in college but that’s been a long while back. I’m having problems pronouncing those words much less übersetzend them. ;o)

The only thing I would add is if you have the 78 or 79 XS11, it will have brass floats and one of them may have a crack in it. Remove the floats one at a time and first shake them and listen for liquid inside rattling around and also try holding them under warm (not hot) water for a minute or 2 and look for bubbles. It's pretty easy to solder up a damaged float.

Geezer

Tony

[mro]

"zur Verbrauchsreduzierung rate ich zum Einbau des Vergasers der XJR1200/1300"

to the consumption reduction I guess/advise to the installation of the carburetor of the XJR1200/1300
____________

'drosselklappensensor'

butterfly valve sensor
____________

"Eine 6mm Schraube nehmen und ein 1mm Loch reinbohren"

A 6mm screw take and a 1mm hole clean-bore
_________________________________________________

I take it that your talking first gen Venture carbs?
I guess you could lean em out and they might work on an XS1100
but I don't see how they would be less trouble than original XS carbs.


mro

[RS Thornton]

mro,

Not 1st gen venture carbs, those are downdraft on a V4, either 34 or 35mm depending on the year. Putting those on would be pretty tough.

[SG-Olli]

Hi Jan,
just send me the text and I try to translate. owiebens@gmx.de
@ all others: The use of XJR carbs is supposed to increase HP and gas mileage.
And the carbs should fit without any alterations except the jets.

[janwic]

Thanks, everyone, for your help. During the last few days I have become suspicious. Have a look a the following pics:

XJR1200
XJR1300
XS1100

Make your browser display the full pictures or use the zoom function to look at the carbs (if the links have gone missing, just google for large pics with the bikes in profile using the above search strings)

What about the float levels? The XS carbs are horizontal, thanks to the bent intake rubbers. The carbs on the XJR1200 are leaning, and that goes for the XJR1300 as well, but the latter has a different carb design where the floats are mounted assuming that the carbs are leaning (look carefully and you'll notice). My question is, do you think this is a problem?

[GNEPIG]

.. MAN!, I want one of these!. what a snazzy lookin ride!

[MAXIMAN]

I WOULD KILL...4 1 of those!

I seriously talked to a couple dealers...one in the UK...about buying an XJR1300 and having it shipped stateside. It simply was going to be a nightmare...

So I had to settle for a ZRX1200R. I'm very impressed with the ZRX but I still want that XJR. I can't for the life of me figure why Yamaha will not sell that bike here.

I have heard it will soon become extinct due to the new Euro emmissions. Air cooled engines have a hard time meeting these new emissions standards. That's the reason I hear they won't bring it stateside.

[strom]

Pics dont do XJR justice... looks better IRL. I like the black and dark green ones.
Dunno bout emissions tho... yurp has a stricter policy afaik. Find a yamaha importer and nag till you get one.

LP

[MAXIMAN]

I spoke with an importer seriously. Worl Of Powersports in Decatur, IL. They import and export bikes all over the world. They are also a Yamaha dealer.

They told me Yam wouldn't let them import an XJR to the states...no matter the price.

[turbopete]

You could buy one over here and pay to ship it by sea. It would take about 16 days to ship from Southampton to LA, cost around $2500 shipping plus marine insurance plus handling plus around $500 for a custom-made crate. I could get you some contact info if you need it.