xbr - recut valve seats

[guest1540]

Hi, I have read elsewhere on this site about the benefits of re-cuting the valve seats on an xbr with the objective of curing engine stall on tickover. Why is this necessary - are the origional cuts wrong? What dose this involve, just freshen up the seats and re-grind the origional valves? Any advice much appreciated.

[guest295]

Engine stall on tickover is due to a poor idle mixture. The valves have nothing to do with it, assuming they're in good nick and adjusted to spec. Beneath the carb is a tiny, hard-to-adjust idle mixture screw. Because it's close to the gearbox housing you can't get a proper screwdriver to it but a small screwdriver bit shoved into a bit of rubber hose will do the job. Try turning it out 1/4 turn. I think that does it, but you may need to play around with it.

[SteveC#222]

The problem was never with the valve seats. As GB500NZ says it was mostly a mixture problem though Honda did release some revised valve clearances later models which was supposed to help.  I also use an Iridium spark plug - NGK    DPR8EIX-9 - which also seems to help. In the end it's something you get used to and just keep the revs up a touch at tickover.  I wouldn't take the head off unless you need to as you'll probably find you have a crack from the plug to the valve seat ....most XBR's do and usually you can ignore it.

[guest1540]

Thanks for the advice on this problem Guy's. Idle screw adjustment and a plug change sounds a lot less hassel than a head off job!