Fitted a new battery this morning, with the intention of firing it up briefly before i progress with the work required. It wouldn't fire up, plugs check wetted up, quick dry off and spark checked outside the pots not the most brilliant of sparks but both sparked. Several in and outs but to no avail, with the ignition on the pump in the tank works continuously is that right ? Cranking seems ok but have re- charged the battery to keep the amps up. The fuel seems ok, but not much in the tank. The headlight and instruments are all off the bike but i don't think that would be an issue. Any thoughts lads ?
Pump always runs. Wet plugs suggest flooding, but unless it is running out of the overflows maybe it isn't that. When the float valves shut, the low pressure fuel returns to the tank. Make sure that the return hose isn't blocked. Make sure the tank breather tube is clear and that the breather valve is fitted the right way around (when not actually riding it, you could actually not fit the breather valve). Make sure you have enough decent fuel in the tank. Fit NGK plugs and caps. Change the HT leads for wire core (if the coils will accept that type, OEM ones should). If all else fails, have the carbs off for a damn good clean.
If you have a weak spark with the plug outside the cylinder it may not still spark when in the cylinder under pressure.
Thinking the same as plugs have been fouled even though the looked dry when i tried them again and again , could it be plugs or cranking taking the brunt and ignition spark weak as a result ? bearing in mind it's a new battery.
Could be, but with a new battery it should operate normally, try new HT lead, caps, after that coils etc
Ha, sorry thought I’d read you’d said it was new, people (me included) are a bit odd when it comes to buying batteries , new tyre £130 “no problem I’ll have it”, battery £60 “erm, I’ll think about it, might get a bit more life out of this one”, save yourself some grief Portboy, buy a battery!
I'm sure you know this but if sticking a new battery onto a bike that is reluctant to start give the battery a charge first to make sure it is tip top
cheers Harry, yes i had to fill the battery with elecrolyte, let it stand for an hour, and then charge. I have a pair of new plugs on order now.
When a carbed SS doesn't want to start and run properly, but just fires for a few seconds or doesn't fully get going; it is fairly common to find the horizontal plug is wet. I never worked out why they do it, but it always seems to be more likely in cold damp conditions. Mine would do it on occasions like that, but if I got into into the sunlight (if any) it would run straight away.
I would definitely get rid of them asap. They caused no end of trouble to my Guzzi and that was in the 80s. But I'm not even sure if they were OEM on the SS.....The ones on mine were crap black rubber.
I seem to recall that the metal caps on the plug leads were to shield the waves that interfered with car radios and nothing else. A common cause of miss fires on 70 & 80’s bikes and always removed.
you need to look at the plug rating. IF the plug has an R in it, then it has an inbuilt resistor. If you then replace leads and caps with resistored leads you end up with a very weak spark, so the resistor is either in the plug - most common, or the leads/cap - uncommon.
I thought we would be on the same page as usual Sev, the std ignition system needs all the help it can get, The number of times I’ve checked for a spark during daylight and thought that there was a problem only to find that the spark I was looking at was standard! I purposely remove all resistors with this I’m in mind, and I remember checking close to a television and it made no difference. Most plugs come with a resistor (as you said) and I think the standard recommendation has one.I haven’t run an early two valve for a couple of years but i use D8EA. (no ‘R’)
I have ordered DCPR8E 's for it , the metal clad caps i would say are original, the bike has only 17k on the clock.
