1979 Restoration

[tbschupsky]

Hey guys, newbie here. I bought a 1979 XS1100 Special “fixer upper” last year for $200. I just successfully finished a bobber project with a 1985 XJ700 and wanted to move onto something with a bigger engine. The 1100 sat for a year in my garage and I just pulled it into my shop about a month ago to have a detailed look at her. Now doing a tip to tip reassembly of it but hoping not to have to dive into the engine. It kind of ran when I bought it (3-cyls anyway) but got her to purr after a good carb cleaning. She spent years being pushed around by previous owners (official and unofficial) looking for someone to spend the time and effort she needed for restoring. I’m determined at this point to be that person. Fortunately, no one messed with it much and everything still seemed to be relatively in tacked. Mostly the elements were getting to her. And, other than cutting away a little of the frame in the back, I don’t want it to lose its ability to be returned to a stock configuration for future owners. However, stock is not a look I care for with these older Japanese bikes so I plan on bobbing the seat and lowering the bike.
I’ve never ridden or actually even remember seeing one of the bikes in real life so I’m hoping I haven’t made a mistake choosing this one to restore. Getting all info on it through the internet, everyone says they’re an awesome bike with tons of power but there are many things that can also go wrong. Guess I’m hoping to be one of the lucky ones that won’t be frustrated with it.
In order to keep the cost of the restoration down, I’m removing all non-essentials like gauges, some electrical devices, fenders, etc. My goal is not to make anything look brand new. It’s just to make her run smoothly and reliably and stop any further deterioration of this piece of Yamaha history.
Here are a few initial questions I have for you guys:
1. Why are there two fuel petcocks?
2. Is there any other place the VIN would be cause it’s not on the steering head.
3. Can the OCTY valve be tossed and just one fuel filter be used?
4. Is the engine VIN and frame VIN supposed to match?
Here are some pix at various stages;
http://i1049.photobucket.com/albums/...5/IMG_2958.jpg
Purchase day!
http://i1049.photobucket.com/albums/...5/IMG_2956.jpg
Purchase day..
http://i1049.photobucket.com/albums/...5/125_2003.jpg
Exploring a new look...
http://i1049.photobucket.com/albums/...5/125_1996.jpg
http://i1049.photobucket.com/albums/...5/125_2012.jpg
http://i1049.photobucket.com/albums/...5/126_2132.jpg
Still want the idiot lights..
http://i1049.photobucket.com/albums/...5/126_2138.jpg
Just a nub on a stand right now
http://i1049.photobucket.com/albums/...5/125_1972.jpg
Finished XJ700 project.
http://i1049.photobucket.com/albums/...125_1969-1.jpg

[Laptop_geek]

Welcome to the forum. I've got a 79F that I've been working on, she's been a lot of fun so far.

1. One petcock supplies the carbs 1 and 2 and the other supplies 3 and 4.

2. If the bike has the original engine the VIN on the frame and engine should be the same.

3. Yes, probably want to use two filters (one for each petcock). Just make sure to shut off the fuel after your done riding it cause it may leak through the carbs into the oil.

4. See answer to 2.

[jwhughes3]

Vin stamped

Tom the VIN is stamped into the neck so you can still read it unless its been ground off. If ground off id get a new frame before putting a bunch of work in it.

John

[jwhughes3]

I cant read it

But i see the vin in pic 2138 on stands stamped in neck.

John

[jwhughes3]

I cant read it

And dont pitch seat and tall backrest. Some folks here looking for that. Put it up for sale in parts forum.

Nice so far.

John

[mikubuilder]

yeah, octy can be ditched in trade off for safety just make sure your carbs are clean ....one petcock will feed all carbs, so you can go to only one fuel filter, but you would loose about 3/4 gal of usable gas in your tank, as the tunnel separates both halves...
that's all I remember nice find, enjoy the ride

[tbschupsky]

My intention is to use both petcocks. Just teeing them together, then into one filter, then splitting off to the 4 carbs. So does anybody know why Yamaha designed the system as each petcock feeding 2 carbs? What was the thinking? Will my system fail if they are tied together? What is the "tunnel" thing? Love this website btw.

[DAVINCI]

My goal is not to make anything look brand new. It’s just to make her run smoothly and reliably and stop any further deterioration of this piece of Yamaha history.

Really?

Then why cut it up?

[lee_dutcher]

Some of us on this forum frown on people cutting up these monsters. But the way i think of it as its your bike so what u want. Make it your own thats what make our hobby fun. Please post more pics of your progress. This IS the best site for our bike. Alot of talent on the board that would love to help when ur bike is down. Helped me out alot!

[mikubuilder]

your set-up should work...just don't understand why would you do it? can't afford two fuel filters? it definitely helps you with troubleshooting if you have fuel separated, meaning left side feeding 1&2 carb, right side feeding 3&4...

a tunnel is a metal piece that separates two halves of the tank, and wraps around the frame....

[tbschupsky]

I think now I'll stick with two separate fuel systems. Probably a better thing in the long run especially since every tee is a chance to develop a leak and all the clamping will look like crap, too. Thanks.