What bike what Carb?

Hutzpah · Posted: October 24, 2008, 11:13 pm Post subject: What bike what Carb?

I'm wanting to know what bike and carbs I've got, the frame and motor numbers are matching.
I know its a 1979 special (was black) looks stock standard.
The frame has -XS 650S stamped on it.

Is that the same as a XS650SF?
What carbs would it have?

ikesXS Carb Rebuild Kit Part #48-7879
Fits: XS650E/SE/F/SF/2F (1978-79) (Who's selling the best kit?)

Spent most of my time up till now painting, as she was rough as.
It was going to be a winter project and I was going to ride it through the summer but each time I looked at it in the garage I just thought that bike looks s--t, lots of surface rust.
Anyway she's starting to look sweet now.

thanks again

Hutzpah

Retiredgentleman · Posted: October 24, 2008, 11:46 pm Post subject: Re: What bike what Carb?

Have a look at this link for serial numbers. There were 3 models in 79.
www.biker.net/650parts_index.html

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

Just because the engine and frame numbers match that doesn't mean the carbs are original. Pretty much any year carb set can be fitted. You'll need to provide more details on the carbs or some pictures, then an I.D. can be made.

The best rebuild kit would contain genuine Mikuni parts. None of the ones out there that I know of do - they're all generic kits containing repro parts. Some of these parts don't fit and work as well as originals. It's best to salvage and re-use as many original components as possible, only replacing what's absolutely necessary. I don't buy the full rebuild kits very often, only getting what individual parts I may need like a float bowl gasket or float needle seat assembly.

Hutzpah · Posted: October 25, 2008, 8:55 pm Post subject: Re: What bike what Carb?

Thanks for the replies.

Retiredgentleman that link was spot on funny thing I
found a similar list on the XS650 Club of Australia buyers Guide www.xs650.org.au/general%20info.HTM (bottom of page)

Anyway looks like she's a SF 1979 model.
Had trouble posting pictures as there resolution was to big will try and sort it out.

Hutzpah

bluebikerblan · Posted: October 26, 2008, 9:52 am Post subject: Re: What bike what Carb?

Who knows if they've been changed from stock? but if not they should still be the BS 38's. Stock changed to BS 34's in 1980 just in time for XS John
to fall in love with them when the XS 650 also went to TCI Ignition.

That's my story and I'm sticking with it. Best, Blue

drifter · Posted: October 26, 2008, 10:36 am Post subject: Re: What bike what Carb?

Don't the 38s have the cast lid and the 34s have the chrome lid? Should be easy to tell that way which one you have.

Dave

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

Yes, but the 38s came in at least 4 variations (externally). Jetting specs changed no fewer than 5 times, pilot jet style changed in '76, and slide type in '78.

drifter · Posted: October 26, 2008, 10:55 am Post subject: Re: What bike what Carb?

Ahh, 5twins. Sorry, I wasn't aware of that.

Dave

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

There were many changes, some minor some major, over the 10 years that the BS38 came stock on these bikes. I know of quite a few but am still discovering new ones from time to time.

You would think that a simple old engine design like this would have simple carbs that would be easy to tune for mods. I've found that's not the case. I've done minor mods and re-jetted the carbs on pretty much every bike I ever owned. Most took just an increase on the mains of a size or 2. On these 650s, it seems you need to change mains, pilots, and fool with the needle setting.

You should see the giant box of jets I've accumulated over the last few years from playing with mine. Oh well, it does keep me out of the bars at night Smile

What Happened to 650rider.com?

Yamaha xs650