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.

that's a little cracker and so nice in unrestored condition.

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.

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!

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

OK thanks, as I thought in that as revs open up the pilot has less influence. I will open a new topic on points/timing before I check that ahead of carb set up.

that's interesting if they come off..the limiters. As you say though, it seems to run well, I will know for sure when its mot is done so will simply balance then and set pilot screws sensibly. My understanding is the pilot screws only really alter slow running. The tank looks new inside which is a good sign, the fuel taps too are squeaky clean.

OK, plugs are m6 and have as you suggested sourced spigots so should be able to cobble pipes onto those. What about these pilot screws with limiters on them? this means I can't seat them then back them out, so am I right putting them to the middle of travel and then tweaking a bit to get the 3/8 turn difference between left and right? So far I notice no real difference adjusting the pilot screws within the limited range although I think they are off balance anyway. That said it runs quite well! OK, plugs are m6 and have as you suggested sourced spigots so should be able to cobble pipes onto those. What about these pilot screws with limiters on them? this means I can't seat them then back them out, so am I right putting them to the middle of travel and then tweaking a bit to get the 3/8 turn difference between left and right? So far I notice no real difference adjusting the pilot screws within the limited range although I think they are off balance anyway. That said it runs quite well!

Hi Drewpy, thanks for the answer as to why the different settings! I will play with the thread size as you say. I was being lazy asking if anyone knew what it was! I'm guessing maybe m6, the balancer pipes are m5.

Hi, I now have a 1977 XS500, very pleased with her and can't wait to get my mot on it! It has the later type carbs I believe. looking forward to being on the forum too. Going through the usual things and got onto carbs. Firstly my balancer adaptor tubes are I think M5 thread and too small for the threaded holes. Can anybody tell me what size the hole is? Then the air/pilot screw. The book says 1 turn out on right hand, 1 and 3/8 out on the left hand. Never come across difference before? Also when I look to lightly seat then back out they each have a square lump on them stopping them screwing right in or backing out...tamper proof? I only have about 2/3 of a turn available so have initially set them at midway on each between the stops. Is this normal on this type of carb? Many thanks for any input.