xt600 55W front master cylinder

[Dolpheus]

Hello All, I ordered a service kit for my 1985 55w front brake master cylinder. Trouble is, it wont fit. Measuring up, the bore seems to be 11mm but the kit diameter is 12.7mm. Anybody got any ideas as to why, is it something to do with the 55w being in the cross over from 84-86 models? Cheers Guys

[BCK_973]

Is that an OEM part?
I know on ebay they offer later models sets from aftermarket.
I got mine for my 55W from ebay germany.It works also for 34L,xt 350,xt-600 but was OEM.
Look for the midle code should be: W0041-00 prefix could be 59X,34L,23L etc.But same kit!

http://www.ebay.de/itm/Yamaha-XT-350-XT-600-YZ-80-YZ-125-Handbremszylinder-Reparatur-Satz-/260958609396

[Dolpheus]

No, not OEM, this is aftermarket service kit I got from Wemoto in the UK,
It should fit a 1985 XT600Z Tenere, but is too big. I've just been looking at more on ebay,
but they say that they're 13mm bore, and mine definately measures 11mm.
I'll have to give Wemoto a ring and sort it. I know the 55W had front brake changes made, just wondered if mine had an earlier, smaller diameter bore from a 1984 model maybe?

[Dolpheus]

Well God bless Wemoto ! Had a look around at other kits for my bike and they all indicated that the bore should be 13mm dia. Speaking to Wemoto on the phone, they told me that the 13mm kit fits the years either side of mine, as I thought. Somehow, mine is 11mm dia bore and they had an alternative that they posted out to me straight away before receiving my returned item. What a service! Now I just hope this bugger fits!
Still need to find out, just out of interest, how mine is 11mm. Was this size ever fitted as standard? Or is it a replacement off of a different bike. It's a Yamaha item, says so on the cover.

[steviebikemad]

Hi there, I've had the same problem with my master cylinder. It's off a 1984 XT600 34L model. The bore measures 11mm inside diameter, but the kit I received was 12.7mm. I did however notice, there is an "11" stamped into the master cylinder when I removed it from the bars. Did your replacement kit from Wemoto fit ok? And if so, what was the part number?