hi mike, just in from the garage, reset timing as follows/ right cylinder on comp stroke/ rotate engine to D line (TDC) reverse fly wheel two teeth then set timing/test light comes on as the second tooth above tdc line moves to center of opening. Same procedure on left (S) cylinder… Plenty of blue sparks at points and plugs/ tried to start her shes having none of it/ plugs very wet. Do you think its carb time? any thoughts would be appreciated kind regards russ
just a thought, had the timing set to the line above TDC line last night which I assume is the advance line, the bike started and ran reasonably well , thought I was getting there but now im none the wiser 
regards russ
Were you using choke? Sounds like it’s flooded, try it without choke.
HEY MIKE when I first tried to fire her I didn’t use choke at all didn’t feel like she was going to start., I eventually used choke she fired backfired and died regards russ
Well maybe timing is still wrong then, are you sure it’s on the compression stroke ~ one way to be sure is take rocker covers off and watch the rockers, when they’re both loose at TDC then must be top of the compression stroke.
HTH (?)
Also as suggested put the old condensers back on, just in case the new ones are causing problems.
hey mike, im going too double check timing tomorrow, fire her up/ if no joy ill swap back condensers and give her another go, thanks for your help mike regards russ
Check resistance of HT caps and compare with a new(er) one, also HT leads (I prefer copper core to the carbon stuff). You can sometimes get a plug sparking in air out of the bike, but high resistance can make it fail under compression.
Ignition coil on it’s way out can give same symptoms, check by substitution if you have/can borrow a spare. Have you checked the throttle stop on the left carb is lifting the slide about the same as the one on the right, and that cables are adjusted so that slides lift together?
    "Ignition coil on it’s way out can give same symptoms,"Â
Agree…poppy bangy ona da guzzi es usuallari coilio…check wiring for chafing etc
Had tank sitting on earth wire once…
This is the difficulty with diagnosing from a distance…
thanks for the above info , all are welcome , I will do mikes re check of timing with covers off ,then condensers, ihave a brand new set of plugs copper core leads and caps on the bench ready to go, with a bit of help ill crack it in the end, I don’t give up that easy regards russ
I had baffling problem with my T3 a couple of years ago. I changed just about everything and even fitted Dynatech 3 ignition. Finally found the coils were failing intermittently. Fitted 2 new ones only to discover one brand new coil was not working at all!!! Once that was diagnosed and replaced all has been well ever since.
Keep smiling,
David.
update, even though you can see the intake valve open and close down the spark plug hole I took the covers off and im certain that all is and was in order/ slack valves at TDC/ timing set at two teeth before TDC for both sides/ next I will swap back both condensers,if no joy all the plugs caps and leads/then the coils, they look old , is there any way that a novice sparky like me can test them? kind regards russ
morning gents, after removing rocker covers I have slack valves at tdc both sides, timing was set correct both sides on the compression stroke (two teeth before tdc) so I will push on one item at a time first and cheapest/ old condensers/ caps/ leads plugs/ coils if I have to, im not a sparky does anybody know of a test for coils that I can do?, I was given a multy meter but don’t know how to use it thought gents please regards russ
You can use Ohms function of the mulitmeter and check if both low Voltage and high Voltage coils have some resistance, if yes then internal wires aren’t broken.
Just seen this again…
Is it still doing this? If sparks, but misfiring, it does suggest bad condenser. Or maybe an insulation problem in the area of the contact breaker wiring.
sometimes I say dumb things/ sometimes I surprise my self getting the balance right is the trick in this life 
Hissing is probably air getting past rings/valve seats under compression at slow engine turnover, remember you checked your compression after the rebuild and it was fine, don’t worry! Not sure how much you know about engines…but valves don’t open at exactly top and bottom of piston travel, it’s more complex than that…if you didn’t touch the bottom end and the engine was running before, then you can’t have affected the valve timing. I still suspect your coils.
Yes you should get hissing (plugs in), as said it’s compressed air blowing past the rings.
Edit: re valve timing, it’s called “overlap”, and is normal. Believe it or not gas doesn’t move very fast when engine is turning over fast therefore valves open in plenty of time before, and close some degrees late as well.
HTH
thank you gents for putting me straight, I need a firm hand sometimes. Still onward and upwards the saga goes on kindest regards russ
I feel your pain. Did you sort it. I have spent 6 months on and off trying to resolve a similar problem. After checking and rechecking everything at least three times went through a systematic check comparing spark on each side as I changes over HT leads, Plugs condensers, cables etc. Did this by using one of the simple in line lamps so that I could observe the spark. Failing intermittently on left. Took tank off and connected it with extension hoses so that I could remove the distributer cap and observe the points in action while running. Turns out that the second set of new condensers were crap as were the first. Old ones back on with a light stone across the points and all seems OK. Now going over to electronic ignition as it is clear that new points are rubbish. Hope you are now sorted cos the bike is fantastic now its back on the road  Â