1977 XS500 points/timing

[petrolhead63]

prior to doing the carbs I will check points/timing accuracy. I have only a Haynes manual and there is conflicting advice on how to turn the engine during work...which differs from that I have used on other machines in the past too ;0) (but then I am probably very wrong)

The Haynes in one paragraph says use a spanner on the nut to turn the engine and adjust points, this is 10mm and to be honest looks a little weedy to trust not stripping a thread?

Then in the timing section it says remove a hex headed bolt and then use a hex key behind that to turn the crank? I have removed the hex headed bolt now and see the hex in the crank end so assume I can turn it with that. Is it better with plugs out?

Any tips to do points/timing check appreciated. I have meters, strobes etc and in the past on other bikes have turned engine with plugs out on kick starter by hand.

I would post a piccy of the beasty but I have not worked out how to make a photo file smaller

[drewpy]

take the plugs out, 10mm is small, I'd use the Hex key to turn engine over

[Cynic]

Plugs out. On centre stand.Top gear and turn the engine with the rear wheel.

Easy accurate and doesent stress anything. Make sure you only turn it forewards though. Dont want timing chain slack messing your settings.

[petrolhead63]

Thanks chaps,  points gaps good but timing is a tad retarded which may be a good thing on modern fuel based on my classic car experience. It seems points just start opening on both cylinders almost on the T marks not on the F marks.

I used the Haynes manual method of hooking up voltmeter with ignition on across moving contact to ground but I think they have got things wrong way round? It says with points closed hook meter on and turn until meter goes to zero, my experience is as the points open the meter goes from zero to reading 12Volts give or take?

The precise moment of spark can be I thought be seen when the points arc/flash? also corresponding to when they break contact and the voltmeter moves from zero volts to 12.

Have I got muddled? I'm so used to strobe timing old cars and I'm getting old haha!

[drewpy]

I thought the T mark was advanced? ie before the Fire (F) mark

I use a dwell meter to set the points the same then strobe to get it spot on (use tippex to highlight the strobe flash)

[petrolhead63]

Turning motor clockwise the F comes before T which is what I would expect, static timing is specified as Before TDC as for most. If it is firing nearer the T it is firing late. My strobe has broken...hoping for a birthday present next week. ;0)

Got my m6 spiggots,,,,typically on left carb the throttle spindle/spring etc is right in front of the balancer plug, so much so I need to open throttle to take it out! it then fouls the vacuum hose and spigot so I cant get it down to idle speed to do balancing, the hose sops throttle fully closing.

[drewpy]

yes, your right, senior moment

[petrolhead63]

its usually me having them ;0) have set statically onto the f marks and it sounds a lot crisper on the throttle...albeit not under load. did carb balance check and they seem spot on without a fiddle.