she just died on me !!!!

JUST FINISHED THE RESTORATION ON MY 76 ST70(6 MONTHS LATER) 90% GOOD ALL WORKING WELL WITHOUT HAVING TO TOUCH THE ENGINE AND ELECTRICS ALL WAS WELL UNTIL I VENTURED ON A 15 MILE TRIP(TODAY),AFTER 6 MILES GOING GREAT AND THEN SHE STARTED TO SPLUTER UNDER STRAIN AND SPULTER AND BACKFIRE AND AFTER A COUPLE OF MILES SHE DIED I AM NO EXPERT AT ALL ON ENGINES,I CHECKED THE PLUG AND IT WAS BLACK,BUT UP THIS POINT IT HAS BEEN RUNNING WELL AND THE PLUG HAS BEEN A MID BROWN (NORMAL) COLOUR,UP UNTIL TODAY,THERE IS PETROL PRESENT AT THE PLUG,BUT THE SPARK LOOKS WEAK,IVE CHECKED THE POINTS AND THEY LOOK GOOD AND ARE AT THE RIGHT GAP,WAS GOING TO CHECK THE COIL BUT WERE IS IT?? AND HOW DO I GET TO IT?? ALSO WOULD I NEED A PULLEY TO CHANGE POINTS ETC,CAN I BUY FROM U GUYS ALSO OTHER PARTS IF NEEDED?? PLEASE HELP......... I WAS GOING TO THE SEASIDE ON IT NEXT WEEKEND(SCARBOROUGH) BUT THAT LOOKS DOUBTFUL NOW OFF TO BED NOW UP AT 5 !! WILL LOG BACK IN TOMORROW NIGHT.
CHEERS ARNY.

Hi Arny and welcome to this forum.
First, it's a lot easier to read if you don't type the message in capitals.
Second, I was glad to hear you were talking about your bike, in the title.

There are a couple of possibilities here, I'll try to sum some of them up for you.
- Sounds like your engine got too hot during the trip (how's the weather over there) meaning it's possible there is a thing or two broken inside the engine: Barrel, cylinder, valves and in the most extreme case the crank.
- Check if there's still enough oil in the engine
- Coil is easiest to acces by removing the fuel tank
- Always try to fit a new spark plug (and set the correct gap) first
- Make sure the fuel tank cap isn't closed (try without the cap fitted)
- All gaskets on the top end engine are in good condition?
- Yes, you need a flywheel puller if you want to change the points

Many thanks for that, o bugger sounds expensive!!!,have tried a new plug no joy,also oil level is good (not lost any),would the engine make any kind of unusual noise if things were broken inside?? there is still good compression? o yes it was a very hot day also dont you think it could be a electric fault? i have replaced the fuel cap with a new chrome one looks good but not original,the bike did start but died again after a minute or two after opening up the throttle and putting into gear,any kind of load on the engine she dies ??

Ive just got her out of the bedroom and ito the light of day and tried to start without the fuel cap(as you sugested) and hay presto she fired up and splutted abit but then cleared?? and away she went as if nothing was ever wrong took her for a spin and again after a couple of miles of 30 +mph she started to splutter and misfire,backfire, i slowed down and she seemed ok again it seems she breaks down under continued load ?? any ideas,also was going to try a ridium spark plug,would this help or hinder

No need to waste the money on an irridium spark plug.
These sure didn't exist back in the '70s...

The problem you have is that the fuel tank is getting vacuum, meaning the carb is unable to suck enough fuel.
Check if the cap is set in the 'open' position and clean it.
The solution (when above doesn't help) is simple: drill a small!!! hole in the tank cap and you should be fine. (or buy a new one)
Also, check the fuel lines for any dirt and while you're at it, I suggest you install a fuel filter.

Thanks Waynus,will give that a go.
ps what i have noticed is sometimes there is slight oil drip comming out from the carberetor overflow pipe after continued use ???? normal?

cheers Ian.

Oil? I bet it's fuel?!
Not normal, but if it's just a drop, I wouldn't mind.
It's just a sign of wear / dirt in the carburetor.

yes its oil !! but only a drop after a run out may have happened 3 or 4 times out of dozen or so rides,does,nt seem to affect the performance,and i have cleaned and put back the original fuel cap so will let you now how things go,when the weather fares up i,ll be out there.........
cheers.

change the coil its breaking down !

Coil ?? do you think so,after changing the fuel cap it seems to run very well again short rides out only 2-3 miles, worried about going any distance after breaking down can coils breakdown under load?,could i change the coil by just removing the fuel tank? or do i have to drop the engine ?,what about the condenser worth changing? points look good,spark is weak at spark plug.
cheers