Master cylinder

[latexeses]

Is there any difference between the 80 special front master cylinder and the 79 special front master cylinder???

The part number varries only in the 2G2 prefix to the part number and a -01-00 on the 79 vs. a 3j6 prefix and a -00-00 suffix.

Any help???

Thanks in advance,

Rodger

[CatatonicBug]

Both front MC's for the SF and the SG use the same rebuild kit. Part number 1J3-W0041-20-00. That tells me that the guts are all the same. Not sure what makes the outsides different though.

[latexeses]

Was watching one on e-bay. Mine sort of looks like an old bale of hay. Was thinking it might be a good chance to help the look of the bike.
This is how it is described...

Fits-1981 XS650H/SH,1982 XS650SJ,1983 XS650SK-1980 XS1100SG,1980 XS1100LG,1981 XS1100SH-1980 XS850SG,1980 XS850LG,1981 XS850SG,1981 XS850LG....

Don't know where that came from.

I'm pretty sure I will be bidding against someone here too.

[Rasputin]

They could have found that info from a site like ...

http://www.benefiscal.co.uk/index.php

I never looked it up but many parts are interchangable for sure.

[latexeses]

Acording to that site they do not interchange.

I was really hoping to get rid of that oogly thing on that handlbar.

Thanks.

[CatatonicBug]

They could have found that info from a site like ...

http://www.benefiscal.co.uk/index.php

I never looked it up but many parts are interchangable for sure.

That's exactly where I got the part numbers for the rebuild kits from. I don't see why they wouldn't interchange. They may be a little different, but they both do the same thing, and have the same guts, so why not?

[latexeses]

The fact that they were one year away from each other had me thinking that any difference would almost have to be cosmetic.

Hopefully it won't cost me too much to find out

Rodger

[fredintoon]

Was watching one on e-bay. Mine sort of looks like an old bale of hay. Was thinking it might be a good chance to help the look of the bike. This is how it is described...
Fits-1981 XS650H/SH,1982 XS650SJ,1983 XS650SK-1980 XS1100SG,1980 XS1100LG,1981 XS1100SH-1980 XS850SG,1980 XS850LG,1981 XS850SG,1981 XS850LG....
Don't know where that came from.
I'm pretty sure I will be bidding against someone here too.

Hi latexeses,
it depends on what the seller means by "fits". Yes, the m/c will look right on the 'bar of each of those bikes but I know for sure the m/c bores are different between XS650s and XS11s so no, they won't work right on all of those bikes.
Best find out the actual bore size before putting your money down.
BTW, if your existing "bale of hay" works OK, think about giving it a coat of paint instead.

[latexeses]

Well, I guess this begs the question. Does anyone know the bore diameter of a 650H front master cyl bore or a 80 1100H master bore????

Anyone???

Thanks,
Rodger

[fredintoon]

Not SH but H?

Well, I guess this begs the question. Does anyone know the bore diameter of a 650H front master cyl bore or a 80 1100H master bore???? Rodger

Hi Rodger,
I was just in my Garage with a mirror on a stick and checked the numbers on the underside of my XS11SG front m/c and my son's XS750SE and XS650G front m/cs.
XS11SG and XS750SE say they are 11/16" (0.6875") bore.
XS650G says it is 14mm or 0.5512" bore.
What the m/c bore of an XS11Standard may be I dunno, but as the XS11Standard and a dual front converted XS650 have the exact same calipers and the 14mm s/c works them just about perfect, my own supposition is that a 14mm m/c will work on an XS11Standard but would have a real soft feel and long travel on an XS11Special, perhaps to the extent that it might not fully apply the brakes before the lever hit the grip.

[latexeses]

Thanks Fred,

One thing I don't need is a set of brakes that won't "fully" stop the bike!

That is good information. I appreciate your measuring those bores. I owe you a cool one.

[bikerphil]

The bore on a Standard (79) is also 11/16". I believe the only differences in the Standard and Special MC's are the slope of the reservoir to accommodate the different styles of handlebars.

[fredintoon]

M/C swapping

Thanks Fred,
One thing I don't need is a set of brakes that won't "fully" stop the bike!

Hi Rodger,
yeah, had that happen to me when my fork seals finally quit to let fork oil drip onto the disks and calipers.
I developed a right forearm the size of Popeye's by the time I got the rig home.
But as Bikerphil sez the Standard & Special have the same 11/16" bore, as a dual front brake converted XS650 has the same calipers as an XS11Standard and as Yamaha are notorious for fitting their bikes with m/cs with too big of a bore; an XS650 14mm m/c would theoretically work OK on an XS11
Provided you put s/st-braided brake lines on it.
My experience with the two XS650 dual front brake conversions I have done is that the "feel" with a single caliper was really wooden, reef like a bastard to make the brake work and no hint at all as to when the brake would lock up.
Adding the leftside disk & caliper improved the brake from a "frenzied grip" to a "reasonable squeeze" to give the same braking effect but the lever felt all soggy. Replacing the stock fabric brake lines with s/st-braided lines fixed the soggy feel.
And finally, did you ever find out the bore size on the m/c you were bidding on?

[latexeses]

I didn't find out what the bore dia. was on the e-bay master cylinder. The auction ended while the discussion was going on. At the rate of nice bikes being parted out these days there will be another one as good or better on there before too long.

Is there a source for this sort of info without having the part in-hand?

According to the list of cross-overs the seller had listed in the auction, it would fit the 80-81 special.

I never even considered the angle of the bars being a factor.

Thanks again, Fred , Phil....