Pics of my 79 XS400 Cafe Racer Build With Single Carb Setup

[weeza1989]

About a month ago I found this bike in a barn. It had not been registered or ridden since 1990. Tires were flat, paint faded and scratched, carbs filthy, wiring chewed, etc, but it had a clear title. I paid $225 for it. After lurking on here and learning some from drewpy and a couple of the others, I turned it into this over the course of about 2.5 weeks. I cut the gas tank on a CX500 down and turned it into the cowl, got a match on the paint and painted the cowl and blended the paint into factory paint, then mixed some base coat with my clear and cleared everything to pull it all together and match the old and new. I built a 2 into 1 carb adapter(best thing I ever did to this bike!) and run 1 factory carb with custom(IE torch tip file) jetting. Has WAY more torque then the dual carbs. Idles nice and runs FLAWLESSLY. Both spark plugs are nicely brown and match perfectly despite what some claim about the firing sequence leaning one side out. I used the factory dual exhaust, chopped it all up, and turning it into 2 into 1 custom pipe. Re-located ignition to under tank, removes blinkers and associated wiring, removed tach, etc etc. Also, I flipped the top triple tree brace up-sidown so I could drop the front on the forks 2" and still mount my clip ons 2" higher. Sorry this is all the pics I have for now. Bike is my daily driver and I have put several hundred miles on it since I finished it a week ago. Thanks for the info guys!

 

[Greasey Fingers]

good job close up photo of the carb please

 

[Spad]

Nice job, blue looks good...Spad

 

[Pork Chop]

Nice work mate.

Did you offset the carb to one side to fix the 1 lean cylinder problem?

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[Scorpio1963]

Excellent job ,that's what I call a person that has vision with his project.Your bike turned sharp as hell.It should serve as an inspiration for others.

 

[Vloukole]

Great bike WEEZA. More info on the single carb conversion and pics please...

 

[xschris]

More on the carb setup please. How do you know it has way more torque with this setup? Did you drive it a lot with two carbs before you changed it? Also how many miles have you run the bike with this setup.

 

[Scorpio1963]

If you enlarge the pic you can see the manifold setup,its basically a y pipe.The carb is hidden underneath the side covers somewhere.

 

[weeza1989]

I will take some better pics of it this evening hopefully. Yup, just a Y pipe. Slight offset but not much. I should pull both plugs and picture them just for proof haha. I rode it about 100 miles with dual carbs. It had a better top speed with duals. It would run about 105mph. Now it runs about 95mph, but for a old bike with drum brakes, I am happy with that. I sacrificed a little top end, but boy let me tell you what! Everything off the line is NIGHT AND DAY difference. The torque is twice what it had with dual carbs. The bike is in my mind much more driveable and has usable power in the low and mid range now instead of everything being up top. I would pit this setup against any dual carb 400 0-75 and would bet money on smoking them although I did lose a slight top speed. I also like the way it cleared up the side view of the bike. Love being able to see right through the bike where the carbs once were.

Thanks for the compliments btw! I still have little detail work and maybe if I get motovated someday I will powercoat the frame, but the goal was to have a cool cafe bike for $500. I now have about $550 in it but Im still pleased. I sounds WICKED too. I will get yall more pics and details on the carb setup soon..... Thanks!

 

[xschris]

A dyno will only tell the truth on the gains But if it works like you say I am sure a lot of 400 guys would use this setup. You may want to think about making some to sell. I think some of your low end is from the long 2-1 exhaust not all carbs.

 

[weeza1989]

I used the seat of the pants dyno. Its also proven mechanical science that a large high volume plenum(IE dual carbs) will make better HP at top end. A more balanced single carb intake will make more torque on low and mid range. I drove it both ways and there is a very notable difference. The exhaust tone also changed noticeably which I found interesting..... WAY too much work to make the manifold to be able to make money selling one haha!

 

[Scorpio1963]

I read somewhere that you can buy these manifolds from a supplier called Linden industries I think,dont quote me.I seen pictures of it.The rubber intake boots are replaced with aluminum ones that use gasket material inbetween.

weeza1989 wish you were closer I`d let you paint my tank and side covers anyday.

 

[drewpy]

wow, nice build, of course we need more pics

 

[weeza1989]

Thank you sir. I have been doing paint and body work for a few years now.

Here are some more pics. I had to flip battery sideways and fab up a aluminum box for airbox and battery and wiring to sit in. I know... I have more detail work and stuff to do on it, but it runs and drives and is very reliable right now, so all that stuff is down the road... BTW, the Harley XR1200 fork gaiters worked really well on this bike and I thought the limited number of pleats on the gaiters helped keep the retro look....

 

[weeza1989]

When it stops raining here I will go get some better outside pics.

 

[xschris]

Nice paint Wont the battery spill acid out of it on it's side like that

 

[weeza1989]

The pic is kinda at an angle so it makes it look more tipped then it is. Is a tight sealed battery though and since this is a kick start only bike, I dont need to utilize 100% of the cranking amps. So far so good! If it ever does cause any problems then I will just switch to a small AGM battery that I can mount ay way I want to.

 

[Pork Chop]

Hey Weeza, did you test the single carb set up with the original exhaust?

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[weeza1989]

Nope. First mod I did to bike was make the 2>1 header pipe and muffler so all carb mods were done after that.

 

[Pork Chop]

I gotta hear this running.

How about posting a video.

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