Archive for the ‘rocker’ Tag

XS650: Rocker Shafts   Leave a comment

Been building myself a couple of XS motors lately. 277° and 360°. Have had the blocks together for some time – gearbox and crank, new bearings and seals etc.

Got round to stripping down an old XS1 head the other day. Just to check her out. Actually not too bad, some leakage around the top of the inlet valves, guides ok, valve stems straight. Cam ok. Rockers starting to wear a little. Decided to replace them and the shafts as I had a new set lying around and I have a new cam.

First you need to remove the 4 press fit sleeves that seal the outer-headstuds. You can simply bash these out but I wanted to remove the rockers and the shafts sit pretty tight (unlike the SR500) so I popped the rockerbox in the oven for a while.

The sleeves knock out easily with an 8mm socket.





Then you can get to the rocker shafts. These are tight.The puller I had rustled up for the SR500 wasnt up for the job but still had the longest 6mm thread I had on hand so I simply packed the outside with a socket and an old gearbox bearing and wound the shafts out.





Total time, less than 5 minutes once heated (if you heat use the oven and not a torch – no point in risking warping the box).

Slapped her back into the oven for a few minutes before inserting the new shafts and rockers. Dont forget to blow out the oil galleries first, and lube.

If wanting to reuse remember to bag and label: left/right, inlet/outlet


Posted May 29, 2016 by xscafe in Motor - Head, Uncategorized

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XS650: Rocker Shaft Removal   Leave a comment

Have been cleaning up a couple of SR500 heads. Ready for porting, new valves and rocker shaft bushing. Needed to remove the shafts. Rooted around in the odds’n’sods bin.

  • 2 x pieces 6mm threaded rod
  • 1 x long open ended 6mm joiner
  • 2 x 6mm nuts
  • 1 x 6mm dome nut
  • 12 x large 6.5mm washers
  • 1 x piece duct tape

5 minutes. No cutting. A perfectly good 6mm slide hammer.


Screw into the rocker shaft. Off you go.


Same principle for the XS.


XS650: Buying Heads or How to Throw Away Your Cash   Leave a comment

Our beloved XS650s have become pretty popular these last few years. They look good. Sound great. Ride well. Classics.

This has driven prices up. And created a market hungry for parts. A market of often inexperienced buyers. Unfamiliar with these machines. Unfamiliar with their idiosyncracies.

Slowly, backyard and enthusiast businesses are beginning to cater for this market. See for example, the Australian XS650 Club here, and JBM Industries. One of the main reasons I started this blog was to promote such endeavours. I have personal experience using most of what you find written about here. The other reason was to provide options to those useless crap new parts as sold by the supplier whose name rarely passes my lips.

Ebay has also provided a ready venue for bike dismantlers (often these bikes are worth a lot more as used parts than as complete machines). Many of these online sellers are straight-up. Others NOT.

One of my pet hates are assholes that sell Heads and Rocker Covers as separate items. If you buy these you are literally wasting your cash. You would do better going downtown and buying some homeless person a meal. Karma rules!

You need to be aware that Heads and Rocker Covers were machined by Yamaha as a matching pair. And stamped with matching numbers.


1 .. matching numbers ... 6198 ... found behind the oil feed pipe

matching numbers … 6198 … found behind the oil feed pipe



2 ..mismatched cam bearing mount

mismatched cam bearing mount



3 .. mismatched numbers ... J1954/9450

mismatched numbers … J1954/9450



4 .. surfaces dont match

surfaces dont match 



5 .. valve inspection port misalignment

valve inspection port misalignment



6 .. single head ... €85 wasted ... and no cam

single head … €85 wasted … and no cam



7 .. single rocker cover ... $72.99 thrown down the toilet ... at least it has the rockers and inspection covers

single rocker cover … $72.99 thrown down the toilet … at least it has the rockers and inspection covers


These sellers know very well that these should be sold as matching sets. How do I know? I have made it a point to let them know. Does it make a difference? Obviously not!

The current Ebay Hall of Shame:

Took me 5 minutes to find these ………

  • thebikebarn … head only, valves and springs, no cam … £60 wasted
  • Impala66k … cover only, no rockers etc … $72.99 blown
  • Impala66k … head only, valves, springs, no cam … $149.99 down the toilet
  • wilto54 … head only, no cam … $125 you may as well have given to a thieving banker
  • independent-cycle … cover only, rockers … C$44.95 don’t you need snow boots?
  • elkhntr6x6 … head only, no cam … $99.95 you should have given to the homeless
  • juan.fernandez … head only, valves, springs, no cam … $99.95 throw a party instead
  • motorcyclesalvation … cover only, no rockers etc … $25.49 you should have spent on new oil
  • bigfootedalien … XS2 cover only, rockers etc … $100 ??wtf??
  • bigfootedalien … cover only, rockers … $57 your ex could have done with
  • bigfootedalien … head only, springs, valves, no cam … $95 do you need a tyre?
  • thecyclebarn1 … head only, no cam … $79.99 worth of BC Buds you missed out on
  • thecyclebarn1 … cover only … $49.99 you paid for scrap metal
  • yourtrashmytreasure … head only, springs, valves, no cam … $195.99 better spent at a brothel
  • yourtrashmytreasure … cover only, rockers … $79.99 worth of condom insurance

Be aware that Engine Cases are likewise machined as a pair. And also stamped.


8 .. matching case numbers ... 3062 ... found behind the clutch pack

matching case numbers … 3062 … found behind the clutch pack



9 .. look here ... 9426

look here … 9426



Photos from Terry, Australian XS650 Club.

Posted December 16, 2011 by xscafe in Motor - Cases, Motor - Head

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