Apparently brake fluid

[reddirtrider]

melts plexiglass.

I tested it out overnight by setting piece in some brake fluid and nothing happened - so, I thought I could use it for a sight glass. After 2 weeks now I went to trial fit the header and felt something drip on me. Since it's raining I checked the ceiling - nothing. Another drip and I traced it to the master cylinder.

That's the last straw for that POS. It's goin in the trash followed by a barrage of cuss words. New paint and rebuild kit go with it.

Anyone have any reccomendations on a replacement? I'm not real keen on getting another OEM as it will probably be in the same condition. How about a Bandit? This is an '83 GS750ES.

[TheCafeKid]

There is a guy on ebay that sells some VERY nice replacements for tween 50 and 80 bucks (just depends on when you catch him i guess) Ive seen one in person, they are nice units, and I plan on replacing a couple of my MC with them as well. I think the bore is SLIGHTLY larger, and some people complain that it makes their lever feel a little mushy, but if youve installed SS lines, this becomes less apparent.

[SqDancerLynn1]

He's got one up now

http://cgi.ebay.com/ebaymotors/FRONT-BRAKE-MASTER-CYLINDER-GS1000-GS1100-GS1150-GS750_W0QQitemZ140327307805QQcmdZViewItemQQptZMotorcycles_Parts_Accessories?hash=item20ac28ca1d&_trksid=p4506.c0.m245&_trkparms=65%3A12%7C39%3A1%7C72%3A1171%7C240%3A1318

[robertbarr]

He's got one up now
http://cgi.ebay.com/ebaymotors/FRONT...1%7C240%3A1318

Looks downright Bandit-like. Pretty sure it's the identical item he has listed for the Honda Nighthawks as well -- they're very similar, with almost certainly the same pivot bolt arrangement & contact heel. Terrific photography, too!

[Nessism]

That ebay master has a 14 mm piston. Suzuki fit a 14 mm piston master on bikes that have single disc brakes, dual disc bikes received a 5/8" piston (approx. 16 mm).

Partnsmore sells a new master with 5/8" piston for a reasonable price. I think they list it under the Yamaha section.

[tejasmud]

usa-motorcycles-inc, yep the one in the listing appears to be the 14mm.

I purchased a larger piston chrome MC from them a few months ago for the 700E, 95 bucks. Pretty decent, with a new switch. The switch is the blade type connectors, but easy enough to convert.

Went OEM on the rear.

[reddirtrider]

That ebay master has a 14 mm piston. Suzuki fit a 14 mm piston master on bikes that have single disc brakes, dual disc bikes received a 5/8" piston (approx. 16 mm).

Partnsmore sells a new master with 5/8" piston for a reasonable price. I think they list it under the Yamaha section.

This must be the one you are talking about.

"Dual Disc Master Cylinder Assembly.
Yamaha Style - Alloy body Master Cylinder Assembly with Lever, Banjo Bolt, Banjo Bolt Washers and Brake Switch. High Quality , Low Profile Design featuring 16mm cylinder with 10 x 1.25 threaded outlet. Fits 7/8 inch Handlebars, Accepts Yamaha Style Left Hand Thread, Right Side Mirror."

Unfortunately the thread is wrong for the mirror mount. Why would Yamaha use a left hand thread on the right side?

[reddirtrider]

BTW, DO NOT use PJ1 Fast Black on any parts that can even remotely have contact with brake fluid. This stuff literally melts upon contact. It's the worst paint I've ever seen in this regard. The primer is still ok, but the PJ1 is wrinked, soft, and worthless. (Hmmm, wrinkled, soft, and worthless - damn that's not good to think about)

[reddirtrider]

usa-motorcycles-inc, yep the one in the listing appears to be the 14mm.

I purchased a larger piston chrome MC from them a few months ago for the 700E, 95 bucks. Pretty decent, with a new switch. The switch is the blade type connectors, but easy enough to convert.

Went OEM on the rear.

I went to their web site and didn't see anything larger that 14mm. If you have any info you can pass on for a 16mm version from them, please post it.