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

enjoy

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.